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View Full Version : Musings on building a workshop and a new machine...



irving2008
06-08-2012, 01:04 AM
So, discussions with SWMBO have got to the point where she wants a consulting room to do private practice (she's a psychotherapist/counsellor) and that means converting the front section of the garage so she can have an external entrance and the back section would, if we go ahead, become a utility room with an entrance from the house.

I can't extend the garage back any more cos of the boiler house and also it would raise issues with neighbours on that side as it would cut out their light into their kitchen. So option has been mooted to build a new brick n block workshop at the back of the garden. This is ideal, it would be screened from the house by an existing laurel hedge and could be around 6.5 x 3.5m internal. With some careful planning I can get everything I need in there... including my 3 bikes. A rough floor plan is:

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So, any thoughts on this layout, the construction of the workshop, etc.? Very early days yet... budget exists but isnt infinite, I reckon it can be done for about 3.5-4k if I'm clever with purchasing...

Secondly, that raises the issue of having to get rid of the old 'British' lathes and stick with my Warco as there won't be room for all of them, plus I can't see me ever getting round to finishing the refurb on any of them in the near future. Anyway there won't be room for anything much bigger.

And then that leads to the mill question... do I keep the Warco MD30 and CNC it as was planned but look at options to convert from a round column to a square column, effectively building something in the vertical using some heavy box section (concrete fill?) and big supported rails (has this been done before?). If I went that route I'd need to get the table dovetails remachined as they are not perpendicular at the mo by about 0.6mm in X across the Y travel. But then again the mill might need to go into storage while the garage is cleared so that might be a time to ship it somewhere and get the work done (and get it converted to ballscrews at the same time). Alternatively I sell it and by something else thats inherently more CNC-able or is already done... an X3 or similar...

Further thoughts appreciated...

Jonathan
06-08-2012, 07:30 PM
Where's the CNC Router :thumbdown:


building something in the vertical using some heavy box section (concrete fill?) and big supported rails (has this been done before?).

Have you seen the builds on CNC zone using epoxy granite? Pretty inspirational stuff...by supported rails I hope you're referring to profile rails as I doubt you could get worthwhile rigidity with supported round rails.

Robin Hewitt
07-08-2012, 04:02 PM
Looks very cosy :beer:

My best design features in my den were a 4 meter length of 40mm x 30" beech worktop with ten double mains sockets across the back edge. Down the other wall another 4 meters of 24" Melamine face kitchen worktop. Underneath the worktops, 47 sliding plastic trays from Radio Spares. Sort of removable drawers in two depths.

irving2008
07-08-2012, 06:31 PM
Yes Robin, can never have enough workbench and there will be lots of storgae under the ones in the drawing.

OK main changes to be incorporated... bike store on ceiling to give more wall/floor space, Dutch dryer style but cleverer... maybe with powered lift :) That frees up space to make room for a small CNC router maybe, or a 3D printer, and/or more workbench...

Bigger windows to increase light and make it easier to get stuff in if need be.

But can't decide what to do about the mill... fix/re-engineer current one or buy a new one (the Amadeal AM30LV @ 1300 is a similar size but more suitable for CNCing... or the slightly smaller XJ25 @ 850)? Reckon I could get 250+ for the current mill...

mocha
07-08-2012, 08:24 PM
Not an original idea but I found a complete fitted kitchen on eBay, fitted out the workshops with some of the under counter units, added 2 cheap worktops from a sale at BQ or similar and sold the remaining kitchen parts for more than I spent buying the kitchen units, the worktops and hiring a luton van to go get it! Larger fitted kitchens work better! :-)

irving2008
08-08-2012, 05:26 PM
Bl**dy planning permission... general permitted development says "can't be >2.5m high if < 2m from boundary. Can be 2.5m at eaves and 4m at centre if >=2m from boundary". I need the height for my bike store so means I have to apply for PP :( grumble....

Jonathan
08-08-2012, 06:46 PM
Bl**dy planning permission... general permitted development says "can't be >2.5m high if < 2m from boundary...

Make it taller than the inside on the outside?

irving2008
08-08-2012, 06:54 PM
Make it taller than the inside on the outside?Very helpful J... its not the TARDIS lol... tho sometimes it looks that way...

Jonathan
08-08-2012, 07:04 PM
Very helpful J... its not the TARDIS lol...

Ahh but you don't need timelord technology - just a shovel!

ptjw7uk
08-08-2012, 07:07 PM
Check with the Local Authority as a lot of the regs have changed and dont need to go to the committee, all done under delegated authority.
Still costs yer though!

peter

irving2008
08-08-2012, 08:55 PM
I looked on the government planning portal under the new 'deregulated' permissions. Its possible that the local council are prepared to relax these as the location in question is already screened by matured hedges/trees on 3 sides so will only be visible from my garden anyway... I'll have to ask informally and see how far I can get... if not, its only 58 to get the drawings reviewed... so thats my next task, do some scale drawings... Sketchup should do the job nicely. Been playing with Draftsight, but either its not intuitive or I've missed the point somewhere....

I'm also wondering about how much of this I can do myself... laying bricks/block can't be too hard? Not sure I fancy digging out 3tonnes odd of soil/clay/crap for the base. Clay subsoil so need to go down 1m under the walls and the floor is 20cm of packed MOT type 1 hardcore and 30cm of concrete then a membrane then screed on top of that - or somehting of that nature, still reading up on the actual requirements...


@Jonathan - if I go below ground level inside I'm going to have a step down. Building regs don't seem to like this as far as I can see, also it could be a pain to lift things in and out, I wanted flat access for a number of reasons...

edit: It seems that the old requirement of being at least 1m from the boundary no longer aplies if the construction is largely or wholly of non-combustible materials and bricks are that last time I looked, so i can make the floor area bigger by up to maybe a metre in each direction. The downside being it'll cost more, 30% bigger base area adds nearly 300 more concrete let alone the digging out costs...

m_c
08-08-2012, 10:59 PM
I'm also wondering about how much of this I can do myself... laying bricks/block can't be too hard? Not sure I fancy digging out 3tonnes odd of soil/clay/crap for the base. Clay subsoil so need to go down 1m under the walls and the floor is 20cm of packed MOT type 1 hardcore and 30cm of concrete then a membrane then screed on top of that - or somehting of that nature, still reading up on the actual requirements...


That sounds a bit excessive to me.
All our sheds with concrete floors are on 10-12" type 1, then 6inch of reinforced concrete, with the damproof membrane below the concrete and brought out and up over enough layers of bricks to ensure it's above ground level. And those floors have had a fair bit of abuse (3 tonne forklift running over them, jacking up various tractors)
Only place near us thats got a 12" float foundation is the neighbours newbuild, as the test bore revealed mine workings below. All the original houses are on strip founds and none of them have fallen down yet! And all his damproofing went below the concrete.


One thing I would say, plan for insulation in the walls, but make sure you build the roof with insulation (i.e. suitably vented with insulation below). The one regret I've got is not doing the workshop roof properly for insulation. I do plan on insulating it, however it's not feasible to vent it properly, so it will probably eventually rot the main beams :-/

irving2008
09-08-2012, 12:28 AM
Just been reading Building Regs Part A Section 2E..

Because of neighbouring trees the strip foundations need to be a min of 0.75m deep and 0.5m wide. I might be a little over the top on the concrete and not enough on the hardcore, but the foundations will be 2 brick courses below final floor level, thats 150mm or so, so there'll be at least 150-200mm of concrete. Already planned for the insulating fill between the walls, with special sound proofing stuff so I can work in the evenings. Roof will be pitched with internal dry-wall soundproof insulation and vapour barrier. There wont be a ceiling as such because i want to use the roof space.

I need to check with Planning I can have the pitched roof nearer to the boundary than normal; I cant see why not, its already well screened as i said. If I cant get that then it puts the rest of the works in doubt, or i'll have to rethink.

Web Goblin
09-08-2012, 12:13 PM
The council dont like you building below the surface because of water ingress I think. If you did that you might need to tank the walls inside below the ground level. I built mine up two courses of concrete block and then timber framed it. Saved quite a bit of money because I did it all myself. I didnt fancy trying brickwork that high but a couple of courses was easy enough with my Brickies Mate laying tool. Insulated all the walls and roof with 100mm thick polystyrene and then clad the outside with plastic cladding. Looks nice even though I do say so myself. I also made the roof trusses from 100mm x 50mm to take extra weight and I use the space for storage. I also modified the roof structure to allow a bigger access to get larger and longer stuff up there.
I will try to post some photos later.

Ian

irving2008
09-08-2012, 06:28 PM
Done some rethinking and some replanning and put some tent pegs and string in the garden where this is likely to go (not so much a garden as a unkempt undergrowth behind the trees). Reckon I can get 6.5 x 4m external which is 6 x 3.5 internal and I can keep it to 2.5m high by putting the door in the end and better utilising the space. So here is plan B in Sketchup this time...

Give me a continuous run of 6m of workbench with the lathe and grinder at the end, lots more windows and therefore light and room to put the bike trainer up when I can't get out and ride... and i could make it 0.5m narrower if need be (but I dont want to). Will make it a single pitch, 2.5m at the front sloping to 2.25m at the back (top of pic)

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JAZZCNC
09-08-2012, 06:49 PM
Make it taller than the inside on the outside?

Ye good idea then when it piss's down you have an indoor swimming pool as well. . . . Lol

Web Goblin
10-08-2012, 06:39 PM
I wouldnt recommend a single pitch roof. I had this on my last workshop and I am glad I didnt do the same on the new one. Having the extra storage space is a major bonus on its own. But if you do go down that route go for some decent roof covering like plastic coated metal sheeting. Got that on mine and its great.
Photo of the enlarged access I left myself to get stuff into the roof storage area.

irving2008
10-08-2012, 08:00 PM
I wouldnt recommend a single pitch roof. I had this on my last workshop and I am glad I didnt do the same on the new one. Having the extra storage space is a major bonus on its own. But if you do go down that route go for some decent roof covering like plastic coated metal sheeting. Got that on mine and its great.
Photo of the enlarged access I left myself to get stuff into the roof storage area.
Would prefer double pitch, but if its with 2m of the boundary and I dont want the hassle of applying for planning permission it has to be no more than 2.5m at the eaves, so will slope it to the back to allow water run off into a gutter and thence to a water butt with a overspill and soakaway. I've had all sorts of issues with a flat roof on a garage in the past so dont want a repeat of that. The only issue with plastic coated metal roofing is the noise it makes when it rains hard :) ... also not too sure of the sound insulating properties. I guess once its lined with 6cm of foam it'll be OK?

Web Goblin
10-08-2012, 09:47 PM
If you are going to build to 2.5mts at one side anyway would you not be as well having a pitch roof? It might not be as much of a slope as you wanted but it would Still be there. The metal roof is not really that noisy and the roof sheets are screwed down on top of the outside sheet of timber anyway.
Photo below (left)shows my workshop roof. The photo on the right shows my nearly complete bike shed with the same type of roof. The roof has the outer sheet of osb, 100mm of poly insulation, then another sheet of osb inside so its well insulated for heat and sound.




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Web Goblin
10-08-2012, 09:49 PM
Forgot to add that the air gap between the roof timber sheet and the metal sheet gives it a good way to breath to keep the damp away.

irving2008
10-08-2012, 11:40 PM
If you are going to build to 2.5mts at one side anyway would you not be as well having a pitch roof? It might not be as much of a slope as you wanted but it would Still be there. The metal roof is not really that noisy and the roof sheets are screwed down on top of the outside sheet of timber anyway.
Photo below (left)shows my workshop roof. The photo on the right shows my nearly complete bike shed with the same type of roof. The roof has the outer sheet of osb, 100mm of poly insulation, then another sheet of osb inside so its well insulated for heat and sound.

Yes it will be single pitched but I wanted a double pitched roof with a useful void in it, but the expemption won't let me have that and I dont want to go to the hassle of getting permission.
So the 100mm poly insulation is between the roof joists and the OSB screwed top and bottom of the joists? Did you use T&G or the plain stuff? What did you treat the OSB with before attaching the metal covering?

I was looking at using Bitumen-coated corrugated sheet like this:
http://www.wickes.co.uk/content/ebiz/wickes/invt/240039/Bitumen-Corrugated-Sheet_large.jpg

Web Goblin
11-08-2012, 12:17 AM
Yes 100mm insulation between the joists with osb top and bottom. I used plain osb screwed down. The grade of the osb is structural I think. It was the one with the better preservative treatment but even so I did give it a couple of coats of creosote or what passes for creosote these days. Seeing as the roof is covered by another waterproof layer you should only need protection from dampness.
My last workshop roof had bitumen coated fiber sheets on it and I really didnt like them. If it is the fiber ones they go soft in really hot weather and hard in really cold weather and after a few years they get very brittle and if you walk on them they break. You need to be really careful when screwing or nailing them down to get the right tension on the fixing so that its not too loose or too tight that it starts to crush the profle and makes it prone to leaks. Also used to have a large tree behind the workshop and in high winds some of the broken off branches punctured the bitumen sheets. You dont get these problems with the metal sheets. Metal stuff can also be repainted after a while to tidy it up again.

irving2008
11-08-2012, 12:52 AM
Tree's are my problem too... I have a mature chesnut tree approx 3m away on one side and a large laural tree/bush at the back and I'm going to have to cut through a few major roots that lie on the surface. Not sure what impact that will have a) on the tree(s) and b) on the ground swell...

Jonathan
11-08-2012, 11:47 AM
Tree's are my problem too... I have a mature chesnut tree approx 3m away on one side and a large laural tree/bush at the back and I'm going to have to cut through a few major roots that lie on the surface. Not sure what impact that will have a) on the tree(s) and b) on the ground swell...

Hmm, we had a youngish (5-10 years) plum tree in the way of where we put the workshop 20x10' shed. The plan was to leave it there, hence why we got 20x10' not 20x12', however surpisingly after cutting lots of bits off my Dad managed to move it so we could have had the extra 2' on the width after all! There's also a mature ash tree pretty close to the end of the workshop, but it turned out there weren't too many roots in the way.

My Dad put insulated plasterboard (like this one (http://www.building-supplies-online.co.uk/kingspan-kooltherm-k17-insulated-dry-lining-plasterboard-3718-p.asp)), which was just plasterboard with 25mm of foam on the back, covering every wall and the ceiling which certainly made a big difference to the temperature and damp.

Not sure what exactly the roof sheet is, but it's black and corrugated:

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irving2008
11-08-2012, 04:13 PM
This is the proposed location, marked out with string. As you can see there's a big tree not too far away and if you look carefully you can see the roots (the string bends over the top of one!)

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Web Goblin
11-08-2012, 09:52 PM
The roots might cause you a problem but you wont find out till you start digging out the foundation and see how they are growing. Another problem is that the tree roots will continue to grow so could be ok just now but could damage the concrete in the future thats why I removed the tree next to mine, I just knew that it would cause problems so it had to go. I think you might need some expert advice on this one.

irving2008
12-08-2012, 01:48 AM
The roots might cause you a problem but you wont find out till you start digging out the foundation and see how they are growing. Another problem is that the tree roots will continue to grow so could be ok just now but could damage the concrete in the future thats why I removed the tree next to mine, I just knew that it would cause problems so it had to go. I think you might need some expert advice on this one.

Yes, trying to find someone...

The current working BOM reckons this 'shed' is near 8k worth of materials :eek: and they say 'materials is only 20% of the job'... err so either I'm very wrong somewhere (been using prices off ebay as a starter) or this 'shed' is going to cost 40k!!!

Web Goblin
12-08-2012, 09:51 AM
I know mate, building prices are scary. I completed mine for around 2.5K, size around 7.5 x 3.5 mt. But I did all the work myself with some help from a builder friend of mine who. The only materials I had to buy new was the timber framing and the osb sheets, concrete blocks and the sand. The plastic cladding came from ebay, major bargain it was, garage door company selling off a job lot. The roofing sheets were leftovers from a job at work that were going in the skip and I happened to be in the right place at the time to re-direct them into my trailer. Timber frame idea is easy to build yourself. Drew the whole thing in autocad and split it into sections to build. Once the floor level was complete I transferred the cad drawing for the wall from paper to full scale on the floor and cut and made all the sections there, same for the roof trusses.

Web Goblin
12-08-2012, 10:18 AM
The cladding I used was similar to this: Royal Crest Sterling Vinyl Decorative Cladding / Siding 200mm wide x 3.81m Long | eBay (http://www.ebay.co.uk/itm/Royal-Crest-Sterling-Vinyl-Decorative-Cladding-Siding-200mm-wide-x-3-81m-Long-/300757554911?pt=UK_Wallpaper&hash=item46068c16df)

Iwant1
12-08-2012, 12:33 PM
I've had all sorts of issues with a flat roof on a garage in the past so don't want a repeat of that. The only issue with plastic coated metal roofing is the noise it makes when it rains hard :

Have you had a look at GRP roofing. I did a roof with a friend of mine as an extension behind his shop. Its uses fibre glass and resin, its easy to put down and has a 30 year life. We didn't put insulation in between the joists, rather OSB3 board over the joists, then 120mm insulation, topped with another layer of OSB3 board, all screwed down with 170mm screws. Planning actually specified which type and size of insulation we needed to use. We had a flat roof with just a rain slope, but it could be installed on a pitch.

65776578

Regarding building the super structure, did you ever watch a program called 'Tommy's ultimate workshop' on Discovery Network. He builds a timber structure on concrete foundations. Its a good example of how you could do most things yourself. Each side of the shed is built on the floor then stood up into place. I did this on a small garden shed I made for my brother. Took me a weekend to complete start to finish. Its not a workshop shed, just a stick all your rubbish in shed. I even fixed the cladding to the neighbouring side before I stood it up into place. Didn't want to go to his side to fix the cladding.

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You have a Selco's builder merchant near you in Cricklewood, go and just have a browse on the materials you will be needing. They have all the equipment for GRp roofing and even have a demonstration video of how to apply it. Its also a talking point when your mates come to see your handy work, lol. I've found they are also the cheapest supplier of timber, and can ask for discount at the checkout.

Web Goblin
15-08-2012, 02:43 PM
Irving,
how are you getting on with your planning?
Is your warco MD30 the same as the Major milling machine? If so how are they?

irving2008
15-08-2012, 05:26 PM
Irving,
how are you getting on with your planning?
Is your warco MD30 the same as the Major milling machine? If so how are they?


MD30 is roughly equivalent to the later Warco Minor (it was rebadged) which they no longer sell and is smaller than the Major, but not much. Table I think is the same size 680 x 180 or thereabouts but the column is 95mm rather than 105mm or something like that...

re workshop, I've now got costs for materials down to 6300 by virtue of overestimation of the cu meterage of the foundations... been looking at sectional concrete buildings as an alternative as the quote for that came in at under 4000 installed plus base but I am worried it might be a compromise too far... will need extensive mods to the roof to make it insulated (by default they are not nor do they have draught proofing!) and would need to insulate the walls too, plus you can't drill into the walls (else it invalidates the 10y guarantee) so not sure how I'd fix electrics (dont want the socket strips on the benches) plus got VFD for mill, Emergency Stop for whole workshop by door, etc. And I want my whiteboard for scribbling on, wall hanger for the bikes, etc etc.... waiting on a couple of firms to explain how they do that... in the brochure it shows offices made of the stuff with plastered walls but nothing on the walls :(

i2i
15-08-2012, 06:19 PM
Walk in cold rooms may be an option for your build, you can pick up reasonable sized ones with failed or redundant coolers for next to nothing. One went on ebay last week that was 6m x 4m for 800.

i2i
15-08-2012, 06:21 PM
Not the most secure buildings but watertight and well insulated. They normally come in sections of a standard size that lock together so you can probably extend as and when you have the panels.

Jonathan
15-08-2012, 06:25 PM
Not the most secure buildings but watertight and well insulated.


That makes it ideal to have a de-humidifier to stop things rusting.


And I want my whiteboard for scribbling on

If only I had a free space on the wall for my whiteboard!

irving2008
15-08-2012, 06:53 PM
Interesting idea, the cold store.... but no way SWMBO will allow something looking that bad in the garden... I'd earlier suggested a 1/2 container (though that would have needed a crane to lift it in, so the panel idea works better) and I'd have to work out a way to fit windows and a decent door. As you say, not exactly secure either.

i2i
15-08-2012, 10:56 PM
Easy to put windows in, just cut hole with a jigsaw, then clad it all over in t&g.

irving2008
15-08-2012, 11:12 PM
Easy to put windows in, just cut hole with a jigsaw, then clad it all over in t&g.

Its a thought... how would you fix the T&G? and that would make it more secure as well. Seems these panels can be bought for as little as 10/sq mtr and for a 6m x 4m x 2.5m high I only need 53 sq mtr or so, thats under 550... so worth thinking about...

Would need to put a roof on it as these things are not generally intended to be standing outside unprotected from what I've researched. But I reckon thats just some 4 x 2 trusses and some OSB and then some metal cladding so relatively cheap. In fact the form on eBay that sell the panels also seel the roofing 4m x 1m sheets 16, so the claddng for the roof is 7 or 8 sheets depending on overlap or under 128


Anyone any idea how these fix together? And would they be strong enough to hang things from the walls (I reckon it'll be OK to fix trunking etc to). I can't find much about their construction online.

i2i
16-08-2012, 12:18 PM
the fridges have camlocks that pull each panel together, but i doubt the panels you're talking about have this. I had one of these fridges outside for a year with no problems.

irving2008
16-08-2012, 01:16 PM
No they dont, they're just 2mm ali skins over 100mm insulation, held together with self-tapping screws... it would need some sort of timber frame. I've not seen the cam-lock ones advertised

However I've just been to look at a sectional concrete workshop and I think it could be made to serve and it is cheaper... not massively so, been quoted 4848 for a 6m x 4m but it would need some additional work doing to line it. The base is definitely cheaper, been quoted 700 for a 6m x 4m 6" thick as against nearly 2,000 for 'proper' foundations.

Lookng at the way its constructed its just cast panels and although the basic full height panels are stock, they cast the rest specific to the job for openings, etc. Obviously they have moulds with movable sides. The roof is identical to what would be used for a block/brick construction except what they offer as standard is very crude and would need to be augmented.

Which got me thinking... if you've pouring concrete, how hard would it be to cast your own panels??? a wooden base, some shuttering, a 'lid' to form the indent and some strategically placed rods to create the bolt holes to pull the panels together... If you were doing it specifically, you could cast in bosses for wall mountings including fixing studs and all sorts of useful stuff... how hard can it be?

Anybody any experience with casting concrete?

i2i
17-08-2012, 12:22 AM
Precast concrete Sectional Garage - Marley Major - 6.65m x 3.25m (21ft x 10ft) | eBay (http://www.ebay.co.uk/itm/Precast-concrete-Sectional-Garage-Marley-Major-6-65m-x-3-25m-21ft-x-10ft-/320960238607?pt=UK_BOI_Containers_Pre_Fab_Building s_ET&hash=item4abab8940f)

i2i
17-08-2012, 12:33 AM
Large Concrete Garage With Electric Roller Garage Door | eBay (http://www.ebay.co.uk/itm/Large-Concrete-Garage-With-Electric-Roller-Garage-Door-/251125910138?pt=UK_BOI_Containers_Pre_Fab_Building s_ET&hash=item3a78454a7a)

WandrinAndy
17-08-2012, 12:38 AM
Precast concrete Sectional Garage - Marley Major - 6.65m x 3.25m (21ft x 10ft) | eBay (http://www.ebay.co.uk/itm/Precast-concrete-Sectional-Garage-Marley-Major-6-65m-x-3-25m-21ft-x-10ft-/320960238607?pt=UK_BOI_Containers_Pre_Fab_Building s_ET&hash=item4abab8940f)

Less than 90 and only 2 bids so far... Probably because the seller's not prepared to post the item...

irving2008
17-08-2012, 12:48 AM
Precast concrete Sectional Garage - Marley Major - 6.65m x 3.25m (21ft x 10ft) | eBay (http://www.ebay.co.uk/itm/Precast-concrete-Sectional-Garage-Marley-Major-6-65m-x-3-25m-21ft-x-10ft-/320960238607?pt=UK_BOI_Containers_Pre_Fab_Building s_ET&hash=item4abab8940f)

Yes I was looking at that one and some others... apart from it being a long way away (7h+ drive) that design with 400mm panels is very old and there aren't enough of them for the size I want since I dont want the up n over door either. There are several others on ebay but none quite suitable for my needs but I'll keep looking.

In the meantime I've done some calcs etc and reckon thats its perfectly feasible to create some timber moulds and cast one's own panels relatively simply and its cheaper by a long stretch, about 2000 less than the ready made workshop in its basic uninsulated state. Also it'll be exactly the size I want with the windows and door i want and not the nearest similar size. And I can incorporate fixings for wall battens to hold insulation and wall boarding etc. at no cost whereas all these options start adding up when you spec them!

I've come up with a modular mould arrangement that'll allow me to cast 6 panels at the same time and 3 different heights and 2 widths of panel to accomodate the windows & door. Once the base is laid and can be used as a work area it'll take me 6 days to cast all the necessary panels assuming each panel can be turned out of the mould after 24hr and left to set.

What I'll probably do is make one mould then cast a couple of test pieces and if that works make the rest of the mould sections...

m_c
17-08-2012, 01:23 AM
Are you going to reinforce your panels?
And how are you going to deaerat the concrete in the moulds?


I'll admit it's something I know very little about, but I've seen one of my dad's mates cast a step many years ago, and he spend ages tapping the mould to get rid of air (vibrating pokers exist for this purpose), then you have to make sure it doesn't dry out too quickly.

irving2008
17-08-2012, 07:50 AM
reinforcement using rebar rods and 20mm glass fibre strands in the mix

yes, can get a vibrating poker quite cheap, or another idea I read about was to make a vibrating table

ptjw7uk
17-08-2012, 10:13 AM
The slabs are made using a vibrating table.
Also upside down, inside surface down and outside up so as the finish can be applied, the opposite to paving slabs.
You would also have to gauge the mix well with the right amount of water etc.
I knew someone who tried the paving slabs for a living and almost went broke till he got the mix right!
Is a wooden workshop a no no.
I made mine out of 22mm ply and 4x2 timber, even bought anail gun to make it all easier.

Peter

irving2008
17-08-2012, 02:58 PM
Peter,

Still looking at wooden option as well, had a look at some examples. Main objections to wood is the permiability, its hard to control moisture and everything I've read suggests machine tools in a wooden workshop is the least desirable route to go. Also there's the maintenance. And its hard to make it as soundproof as a concrete or brick structure and thats important. Finally you can't site a wooden workshop within 2m of the boundary because its not non-combustible, so I'd have to make it smaller. Not that sure its much cheaper either! So while its still an option, its least preferable.

Another opton is timber frame but plastic coated metal box cladding over OSB as used on the roof. Again the soundproofing might be an issue unless I use a lot thicker foam.

irving2008
20-08-2012, 10:19 PM
Just an update...

Found 2 companies on the web (not one of the big two suppliers) who will sell me just the panels and fixing bolts and am waiting on their quotes. I'm also in a long email conversation with one of the big garage manufacturers who are close to agreeing the same thing, though its not something they normally do. But their price is only 24 inc VAT for a standard panel 2m x 0.6m... that means the whole workshop will be under 800 for the walls (by comparison the other major manufacturer will only supply 'a limited number of spare panels' at 70 + VAT). All in I'm looking at under 3500 fully insulated and ready to use.... ok I have to build it myself but hey, how hard can that be?

I've looked at acquiring an existing garage... even one thats close to me and is big enough to make it worth considering (arbitrarily set as the number of panels I need to add is no more than 1/2 of what's there already) will need a 3.5tonne van to shift it and thats going to cost me 150+ to rent for the day so I'm looking in total at getting on for 750 to a 1000 second hand... might as well buy new and avoid the hassle and effort of carting it over...

Jonathan
20-08-2012, 10:32 PM
My shed/workshop is wood and it's clear that moisture penetrates it from the amount the de-humidifier collects when it's damp outside. With the de-humidifier and heater (thermostat set very very low) I've never had problems with corrosion, unless you count the time a bottle of ferric chloride dripped on the lathe!

Soundproofing is an issue when the router's running, but the other machines are quiet enough. For that reason I try not to run the router after 9pm, though it's been known for me to still be up there well past midnight...

I wasn't aware of this within 2m of the boundary regulation. Mine is less than that as it's only about 0.4m from the hedge. I think the 20*10' structure cost about 2000 with delivery and installation, plus the cost of the concrete base and insulating it. Maybe it's worth asking some suppliers what they can offer?

Web Goblin
20-08-2012, 10:47 PM
Building it isnt hard but you will need help. You do need to make sure your foundation is fairly level though. Pick a day thats not windy and start from a corner. How are the joints on the ones your looking at sealed?
The prices you have got so far are great. My original plan was a concrete sectional garage as well and I had enough panels to make a single garage but wanted more and I was quoted 80 plus for each panel. I think it was a Marley one I had. Ended up giving it to a mate of mine, then had to help him build it.

irving2008
20-08-2012, 10:47 PM
Wood seems to be expensive... I can get something like this: 20' x 10' Shiplap Tongue and Groove Workshop Shed - Premium Range - Wooden Sheds (http://sheds.co.uk/wooden-sheds/quality-garden-sheds/20-x-10-shiplap-tongue-and-groove-workshop-shed.html) for 1300, heavier duty than the 800 versions... but I'd still need to insulate it and at the end of the day it would need maintenance and the like.

Also would need upgraded windows etc. the 3500 I'm working to includes uPVC windows and door with 3point security deadlock (apart from the mill and lathe theres a few grands worth of bicycles etc.)

Hopefully I'll settle on a supplier for the panels tomorrow and I've also got someone coming to quote me on the base... already been quoted 790 for that which is about what I can buy the raw materials for!

irving2008
20-08-2012, 10:55 PM
Building it isnt hard but you will need help. You do need to make sure your foundation is fairly level though. Pick a day thats not windy and start from a corner. How are the joints on the ones your looking at sealed?
The prices you have got so far are great. My original plan was a concrete sectional garage as well and I had enough panels to make a single garage but wanted more and I was quoted 80 plus for each panel. I think it was a Marley one I had. Ended up giving it to a mate of mine, then had to help him build it.

Assembly depends on which manufacturer. The 'generic' ones are just mastic butt joints as is one of the main manufacturers. The other is a T&G arrangement similar to the Marley (which incidentally you can still get as well, but they were expensive too).

Foundation isnt a problem, will be 4" hardcore, 2" blinding sand and a DPC then 8" deep concrete, 12" deep round the sides to 6" out from the hardcore. When they build these normally the sections are free standing and then sealed on the inside with a 1 - 2" fillet of mortar to make it weathertight. I'm considering setting them in a 5mm mortar bed to make it weathertight, then internally I'll put down a 15mm screed and then 5mm of floor levelling compound to get a perfect smooth level finish. And then I'm going to paint it red with floor paint. 'Cos I've always wanted a red floor in the workshop :)

Web Goblin
21-08-2012, 06:58 AM
Floor in mine is red as well but I have a wooden floor. It does look good. Just as a side point red floor paint takes about a week to dry when you put it on top of creosote treated wood.... who would have thought it!

irving2008
21-08-2012, 04:33 PM
So the quotes are in...

Company S. Panels are 6' 6" x 2' and 3' 3" x 2' (seems imperial is rife in the concrete panel industry) 33.6sqm @ 1580 inc fixings, delivery & VAT = 47/sq m

Company N. Panels are 7' x 2' and 4' x 2', 36.5sqm @ 1999 inc. etc. = 54.80/sq m

But the current 'winner' is

Company H. Panels are 6' 6' x 2' and 4' x 2', 35.2sq m @ 1070 inc. etc. = 30.4/sq m


Waiting on one more quote...

Would prefer the 7' panels as less roof working to do, but almost double the price!

irving2008
21-08-2012, 07:10 PM
Well after a long chat with one of the suppliers about how these are constructed and being advised that "it's not rocket science and you'll save about 2,500 doing it yourself", I've being playing with Sketchup, as you do lol....

This is based on the 6'6" panels so there's a few lumps of wood to provide a wall bar and purlins with OSB cladding. Might put some T&G over the cladding to prettify it so SWMBO doesnt get too upset... she wasn't too impressed with the idea of concrete though what she thought it was going to look like I still have no idea...

6636

ptjw7uk
21-08-2012, 07:36 PM
Irving, what do you propose for the roof.
I for one would go for the plastic coated steel sheeting as its really upto the job.
Used it last year when I enlarged my concrete garage by 4' 2" wide and 1' in length and still couldnt get the car in it!!

Peter

irving2008
21-08-2012, 07:50 PM
Roof will be Plastisol coated steel box-corrugated sheet over 18mm treated osb on top of the purlins, 100mm poly insulation between them, and 18mm OSB inside... all sealed with expanding foam... snug and dry :) All sourced off eBay very cheaply :) Whole 6m x 4.2m approx roof will cost about 400

ptjw7uk
21-08-2012, 08:02 PM
Just a heads up on the steel sheet, get the right screws!
I had some from another job but the screw pitch was to fine and stripped when pulling the edging onto the sheet, ended up with bolts!

peter

irving2008
22-08-2012, 01:41 PM
Designing this workshop is as bad as designing a CNC machine, so many ways to do the same thing...

So anyway, I'm reviewing the internal heights and decided it would be beneficial to have the higher side at the back, so I can lift the head on the mill and still get the drawbar out... plus I don't need the headroom over the bench. But that means having the guttering at the front, which isnt so aesthetic but I can live with it. I can't see any negative reason not to have the slope to the front, in fact that way round it possibly makes the building less obtrusive. Also going to bring the purlins directly onto the wall plate at the front, saves effort and only loses 20mm height over the workbench, and makes the fascia smaller, again less obtrusive.

It also means I can run the gutter into a water butt which overflows into a soakaway (there's no room behind for a water butt, only a small soakaway). That potentially gives me a reservoir of cooling water for the future (after filtering). I considered running a cold water feed from the nearby outside tap so I can make tea ;) tho I'd like a sink and a water bath for PCB etching/cleaning but you can't let that run into a soakaway so no washing facilities. (also starting to get dangerously close to 'permanent' and planning permissions).

Web Goblin
22-08-2012, 10:30 PM
You need to be careful about the distance from your foundation to your soakaway drain. When I did my conservatory a few years ago I had to dig it 5mts away from the foundation and also 5mts away from the boundary of my garden. I dont know what the planning regulations will be in your area. You dont want to wash away your foundation in a few years.

irving2008
22-08-2012, 11:56 PM
You need to be careful about the distance from your foundation to your soakaway drain. When I did my conservatory a few years ago I had to dig it 5mts away from the foundation and also 5mts away from the boundary of my garden. I dont know what the planning regulations will be in your area. You dont want to wash away your foundation in a few years.Hmmm, can't see any regulations pertaining to that. At least one of the gutters on the house just exits onto the flower bed with nothing special under it and as far as I can tell has been like that for best part of 80 years. I was planning to dig a hole about 2' round and 2' deep and fill it with gravel and let the overflow from the water butt exit into there. It would be 'downhill' from the foundations but at least 8 metres from the house. 5 metres away in most directions would be outside my garden lol, and there isnt anywhere that's 5 metres from all boundaries! (garden is long and thin)

Web Goblin
23-08-2012, 07:03 AM
I do remember asking the local building officer about that regulation when he stated it and the answer was something like "you need to do it to get your completion cert". I ended up with a 1 cubic meter hole and thats alot of digging. It does come in handy when Im cleaning out the filters of my fish pond though.

irving2008
30-08-2012, 09:09 PM
So I had 2 online quotes for the base and one Romanian guy that came round. The 2 quotes were around 700 but when I queried the detail suddenly they didn't want to quote any more... the third went away and came beack with a quote of 4,500 ouch... just for the base!.. I asked for a breakdown and was told materials are 1800. Hmm, well my ebay costings suggest 1/2 of that. But that means labour is 2700 for 3 people for 5 days... well I suppose if you're going to dig it all by hand... well thats way outside the budget.... so might have a rethink there... anyone got a microdigger they could lend me for a couple of days?

The tree roots aren't a problem.. as long as the tree is thinned about 40%... thats another 700 :(

irving2008
31-08-2012, 08:05 PM
Well one of the 'online' quotes came back and actually quoted for the job I asked for... 5250 :crushed::crushed: since when did digging a hole get so expensive??? And how come thy're materials and plant costs are so much higher than what I found on the web... e.g. microdigger hire, 3 days, from a local firm 65+VAT a day, the quote 122/day??? WTF?

Anyway, suffice to say i dont have the budget for that... so I'm going to have to do it the hard way... dig it out myself. What i need is a way to lift/transport 1 ton bulk bags. I'm thinking of welding up something out of 4 x 2 steel box thats essentially an a-frame hoist on big wheels.... any thoughts?

m_c
31-08-2012, 08:29 PM
By the time you take in 3 days digger hire, at least 2 guys, skip cost, setting up time, wood to set-up, it's surprising how things mount up. Personally I'd go for a mini-digger, as the extra weight makes a big difference. How wide is your access?
A power wheel barrow may also be a major benefit. If you need to haul stuff a big distance, you'll wonder how you'd ever of managed without one!

Concrete, I'd get ready mixed. It costs more, but mixing yourself, by the time you've finished, the other end will already be setting.

Have you budgeted in a power float to smooth of the concrete before it fully sets? Might seem pointless, but if you're not putting down an internal floor, they make a huge difference to smoothness.


Have you tried asking around to see if there's any local builders willing to help you for a couple days for suitable tax free payment?
Having an experienced builder/brickie can make a huge difference, and keep you right.


As for 700 to prune a tree???
What they doing, spending days manicuring it with a pair of scissors?
Given those pics, it's no more than a days work, and if you deal with the prunings, they've got pretty much no costs other than labour...

irving2008
01-09-2012, 12:05 AM
Thanks guys.

I had 3 quotes for the tree, all were about the same... 3 guys for a full day they reckoned plus carting it all away... was estimated at between 3 and 4 tons of wood...

The access is only 720mm wide...can get a microdigger in there, just about.. can just about get a 6cu ft (0.6cu m) powered barrow through there - hiring those two is nearly 600 for 2 days

The ground needs levelling and then digging out to at least 400mm deep for 150mm at the edges or so i have been advised by 2 different builders because of the tree roots, only 300mm in the centre (100mm ballast, 50mm blinding sand, DPC, 50mm insulation, 100mm concrete). Thats around 15 cubic meters, or 22tons of spoil to be shifted. Even a microdigger's 0.022cu m bucket will take 2 - 3 days digging. Then I need to barrow in 3.6 ton (2.6cu m) of ballast and 2 ton (1.3cu m) of sand and finally pour around 3.7cu m of concrete... while a digger+powered barrow will make it easier, I will need to do this over the course of a few weekends/evenings because I have no holiday left til Jan. Even if I took the time off work unpaid i couldnt keep both bits of machinery effectively utilised on my own. So its all going to have to be done by hand... the ballast and sand gets delivered in those 1 ton bags and if i take the spoil out the same way i wont need to hire 2 x 6yard skips for a week, I can get a grab truck to come and lift them away, which is only 25% of the price of skips. so its how to lift those bags... else its use a standard 85kg (0.05cu m) barrow... thats 300 trips out and 78 back lol but at least i can take one out and one back in the same journey

irving2008
01-09-2012, 12:44 AM
hmmm... bulk bags are either 85 or 90 cm cubes... they wont fit down the side passage so its still going to have to be a barrow, powered or otherwise, and a spade...

irving2008
02-09-2012, 02:46 PM
Well did a test dig this morning, marked out 1m x 1m in the furthest corner (so SWMBO doesnt get too upset lol) and got a "grub mattock" from B&Q. For those of us of a "gardens are somewhere to look at and sit in" persuasion, this tool is a revelation and great fun to use, until your arms get tired that is... makes short work of roots and anything else (well ok maybe not the 3" ones) and makes it very easy to lift the result with a spade...very quickly took off the top 5" or so apart from two 3" dia roots that were just under the surface... I'm still amazed how much spoil comes out of such a small space !

Looks like I'm going to hire a microdigger and powered barrow for delivery Friday morning, that gives me most of Friday, Saturday and Sunday to dig it out and get the spoil to the front garden, grab truck to retrieve it on Monday.... at least thats the plan...

i2i
02-09-2012, 03:55 PM
this reminds me of the age old question...

How much earth is there in a hole measuring 1m x 1m x 1m. ?

Web Goblin
02-09-2012, 09:03 PM
i2i,
loads. I found that out when I had to dig a 1m3 drain for my conservatory.
Irving, the old grubbing mattock is a great tool. I used one as well for my foundation and I'm currently digging out a pathway at the back of my workshop with one as well. A mini digger and powered barrow will save you loads of time. Would it be easier to hire an 8yarder to dump the soil into? Try not to copy me and pull the track off the digger. Its a right pain in the arse to put back on.

Jonathan
02-09-2012, 09:14 PM
Would it be easier to hire an 8yarder to dump the soil into?

Just dig another hole and put the soil in that...:barbershop_quartet_

irving2008
03-09-2012, 01:13 AM
i2i,
loads. I found that out when I had to dig a 1m3 drain for my conservatory.
Irving, the old grubbing mattock is a great tool. I used one as well for my foundation and I'm currently digging out a pathway at the back of my workshop with one as well. A mini digger and powered barrow will save you loads of time. Would it be easier to hire an 8yarder to dump the soil into? Try not to copy me and pull the track off the digger. Its a right pain in the arse to put back on.

will need 2 x 6yarders at least and thats silly money here in London, over 500 plus I dont know if I'll be finished by the end of the weekend. I'll use the digger/barrow to shift the bulk of it before they go back and finish by hand. The advantage of the grab truck is that it'll come when I'm ready and costs me nothing until I am...

irving2008
03-09-2012, 01:15 AM
this reminds me of the age old question...

How much earth is there in a hole measuring 1m x 1m x 1m. ?Apparently 1.6 tons approx must have been taken out.... but there's none in the hole now lol...

Web Goblin
03-09-2012, 07:01 AM
Apparently 1.6 tons approx must have been taken out

No wonder I was knackered after digging mine out.

At 500 plus no wonder you dont want a skip. I think mine cost about 100.

irving2008
06-09-2012, 12:46 AM
Well tree is now well lopped, much to SWMBO'd dismay as now there is no foliage left. She wasn't/isn't happy, mainly because we can now see the flats at the end of the garden. But on the advice of 4 different tree companies, all who quoted the same price within 20, all the upper branches were dead wood or rotten and all the diseased foliage was on the outside only and there was a strong chance of branches coming down and destroying the fence or falling on someone... Basically it should have been cut back every two or three years, not 10! so now its a much smaller tree and there's no chance of branches falling on the workshop roof...

But it also means I can get on with digging foundations... so there's a microdigger and powered muck truck coming on Friday morning and the weekend should see the hole dug and a big pile of earth on the front drive.... I may have to shore up the back LH corner as it'll be 800mm - 1m deep there by the time I've leveled everything... I'm wondering if I should either build a retaining wall or simply design the concrete pour to provide some butressing in that corner, but still leave a channel between that and the main shed base... ideally the base should be 20-25mm proud of the ground level but thats not possible cos of the slope into that corner. So the plan is to make the hole 75mm bigger all round and after the concrete has set fill the gap between concrete and soil with 20mm gravel so that water run off the soil or off the concrete has a soak away. This should also deter roots from trying to grow back.

I'm hoping if I go down 300mm elsewhere it'll be clear of roots etc. If not I'll go down another 100mm. The centre will be 100mm ballast, 25mm sand, dpc, 75mm insulation and 100mm of concrete - 300mm deep.

So Friday will be using the digger to lift all the big roots and lop them off 100mm or so outside the base... then dig it out starting at the high point at the back. I made a simple clamp with a camera thread to mount my laser spirit level onto a tripod to use as a basic levelling measure. That should be good enough to +/- 1mm.

Still got to find a local source of rebar, either rods i can weave into a mat or ready woven matting... and got to get 21m x ~300mm of 18mm osb for shuttering and a load of 2x2 to stake the ground out and support the osb during the pour...

Web Goblin
06-09-2012, 06:59 AM
Nice to see progress on this one. Happy digging.
Instead of re-bar you could use this stuff: Concrete & Screed Fibres (http://www.concrete-fibres.co.uk/concrete-fibres/xt-fibres-12-18mm/prod_15.html)

I used it on my foundation for the workshop and the bike shed. Big benefit is that you can drill anywhere without worrying about hitting bar.

irving2008
06-09-2012, 02:11 PM
Yes, I've looked at that stuff. If you go on the concrete industry's website and look at the pages that talk about reinforcement they are quite clear that steel is the way to go for anything involving tension so large slabs subject to ground heave, like on london clay, its needed. Fibres are good for other stuff, particularly controlling cracking due to shrinkage and the two should be considered complimentary.

The concrete I'll get pumped in will have fibres in it, but the firm in questions still recommended 'fabric' (thats the industry term for steel mesh). I need type 142 apparently, 6mm wire 200mm mesh. and It shuld be at least 50mm from any surface so you shouldnt hit it with a drill under normal circumstances, a 2" hole in concrete is quite deep.

Looking at using sleepers or 75mm half-poles as a retaining wall rather than concrete, it'll look nicer and is quite cheap.

Web Goblin
06-09-2012, 09:16 PM
Going for both methods should give you a very stable base. The pump method is great to watch. When we did our conservatory we had to get a pump in to over the house to the back garden. Emptied a fully loaded concrete lorry in about 30 minutes. All the kids in the street were out to watch.

irving2008
06-09-2012, 11:56 PM
Thats a lot of concrete! were you doing it yourself? I've never laid this much before, I am, shall we say, apprehensive, about it.

But my first issue is whether I need to build retaining walls or not. the ground slopes up to the left and towards the back. The far left corner is 58cm higher than the datum (front right corner), Frnt left is 28cm higher as is rear right. So if i dig down 275mm (so the top of the base is 25mm above datum) I have a 'wall' of earth 855mm in the left rear corner. I think that needs retaining. and similarly the left and right side need retaining to about 1/2 way along the base and grading from there. Got to find a solution that doesnt take up a lot of space else I either need to move the base over a bit, or make it smaller... and I've already compromised on size :(

m_c
07-09-2012, 01:54 AM
A retaining wall probably isn't entirely necessary, as the worst that would happen is it collapses down against the workshop wall. However that would eventually lead to damp.
If you put in a retaining wall, it stops moisture being held against the wall, and should stop moisture soaking through the wall.

Web Goblin
07-09-2012, 07:09 AM
We got a builder in to do the conservatory but I did do quite a bit of the work myself. The concrete pour wasnt really difficult. Started at the middle and worked out from there. The hard part was walking about in the concrete while pouring it and trying not to fall in it!
How close are you building to your boundary? Can you build the retaining wall at the boundary and leave say enough space to lay a row of 450mm slabs around the workshop for maintenance access?

irving2008
07-09-2012, 07:26 AM
about 600mm from the boundary at the back, 900mm to the LH side. My problem is that adding a retaining wall adds another 300mm to the dimensions and already SWMBO isn't too happy. I think I'll see if i can take it back further, but I cant go any further left because of a laurel bush that I want to retain. If I can level it more on the left and leave just the need for a rear wall and grade the RH side a bit that should be OK. Else I'm looking at 700 of sleepers to make a wall, but at least that won't need a concrete foundation, just some post-crete'd holes. A poured concrete wall is another option at only .7cu m of concrete (100mm wide at top, 300 at bottom, 4.1 m long, 800mm high) but needs some complex form work and wouldn't look so nice.

Web Goblin
07-09-2012, 08:41 AM
A concrete wall will look fine with a bit of roughcast on it and some flag stones on top. Seeing as your getting the concrete anyway you need the foundation and shuttering.

irving2008
07-09-2012, 08:05 PM
Well end of day 1 and not entirely to plan. Digger didnt turn up til gone 10 but I'd spent the first couple of hours chopping up a crazy paving path that cuts across the corner of the dig. With a cold chisel, a 5lb club hammer and the bosch power chisel... hard work... if I'd known how difficult I'd have hired a kangol but i would have only needed it for an hour or so... then the Muck Truck (powered wheelbarrow) got stuck in the garage back door.. the gap was 705mm the muck truck was supposedly 680mm... yes apart from the hubcaps which needed another 30mm, so had to take the door off...

Anyway, dug out about 1/4 of the area at the deepest end, down to 730mm or so... will finshing digging the rest before doing the final 100mm just in case my land surveying is a bit off...

will put up some pics later when I've eaten and dragged them off the camera... but here's the boys toys taken on my phone...

6797

irving2008
09-09-2012, 12:31 AM
Day 2. Digging continues... couldn't start making noise til 9:30 cos SWMBO said it wasn't neighbourly, so was out to Wickes at 7:30 to get a 1800mm spirit level, a folding builders square, and a six pack of 2 x 2 to make stakes from. Had my youngest son helping today driving the barrow so that made it faster, tho the amount of damage to the garage back door frame does make me question that... I was planning to replace that door with a uPVC one sometime as the door itself is going rotten - so might be sooner than later, well have to order doors/windows for the workshop so whats one more door lol (about 250 or so in case you were wondering). Masses of tree roots made digging slower than hoped, each one having to be chopped several times, the digger isn't man enough to lift a 3" dia root and there were about 2 dozen of them under the surface (and still more where I've not yet dug I'll venture). Really needed a chain saw, the circular saw can't handle living wood well, so really only had the mattock/ax and that makes it hard work...

I'm hoping tomorrow will see the end of the digging out, leaving Monday for levelling and tidy up of the sides... at least the digger is in the hole now, was a scary job driving it down the short ramp of earth. Apparently I should leave a ramp in then dig the ramp out after, but that makes it harder, esp as the only place to put the digger will be in a bush I want to keep. I'm thinking 6 pieces of 4 x 3 on end to make 4 x 9, 2.4m long with some 2 x 2 spacers will make a couple of ramps @ 12% (is 4 x 9 overkill for .9ton?) and they can be reused for the shuttering or the out of sight framework for the benches.

Decided to go for a concrete retaining wall, with some extra mesh in it and a DPC between it and the earth, and I'll bury a land drain pipe behind the dpc.

Now, how do you fix a concrete fence post? managed to catch one with the digger when I got confused with my levers :( and it cracked about 6" up from the base... I guess I need to get a new one but how do I get the old one out?? I'm wondering if the digger will lift it out with its cement block... assuming it was post-creted...

irving2008
14-09-2012, 08:08 AM
Well, just an update... today sees the completion..... of the hole...

Even with the digger and the powered barrow, this was a task I seriously underestimated.

Firstly, 1 foot or so down and we hit London Clay... initially that was easy to dig, like spreading butter, but once exposed to the sun it turned into concrete. Even harder were the deep patches of water-worn stones embedded in the clay. Sadly no fossils though I did break open some likely looking nodules of flint.

Then it rained, albeit briefly, on Wednesday night. By Thursday morning my hole wasn't looking like a swimming pool as I feared but the clay had gone all gloopy and walking on it meant you sank in about 2". It was unworkable for a couple of hours til it dried in the sun and then it was unbreakable :(. But I persevered. Damp clay is incredibly heavy so I found I could only half load the barrow else I couldn't manouver it. So now I have pile #2 in the drive (pile #1 was removed by grab truck on Monday) - something like 17 tons of earth has been shifted, all on my own.

68656866

All the wood for the shuttering is now sitting on bricks under a tarpalin, so will assemble that this weekend in sections and do a trial fit. Then have to order the reinforcing mesh and the ballast and sand. No powered barrow this time so willl have to manually shift it all, but theres a lot less of it... biggest problem now is finding the time.

Here's the design of the retaining wall to go across the back.

6867

irving2008
15-09-2012, 12:15 AM
Well the hole is done...

A second grab truck (same firm) removed pile #2 today. Both piles have gone to be landfill to sculpt a new golf course in South Mimms. (not a bad business this grab trucking... you get paid to take it away and paid to deliver it on the same day lol)

6877

This is before I cleaned it up and tidied the edges... its 6.34m x 4.14m and 275mm deep in the nearest corner, 800mm deep at the far lh end. The bottom is flat to within 3cm which I reckon is good enough.

wilfy
16-09-2012, 02:32 AM
loks awesome, can't wait to see it all done and your machines in there.. keep up the good work

Iwant1
16-09-2012, 03:48 PM
Irving, its amazing how fast you work, from drawings to actually getting started. I suppose when there's something on your mind and you're thinking about it all day, things get done. Keeps the pics coming, its a very interesting thread.

I'm surprised your other half hasn't told you to keep digging and make a swimming pool instead, lol forget the shed and concentrate on relaxing.

irving2008
16-09-2012, 05:52 PM
Irving, its amazing how fast you work, from drawings to actually getting started. I suppose when there's something on your mind and you're thinking about it all day, things get done. Keeps the pics coming, its a very interesting thread.

I'm surprised your other half hasn't told you to keep digging and make a swimming pool instead, lol forget the shed and concentrate on relaxing.

Well I'm still not 100% sure how to do the next step. I understand the general principles but the detail still needs hammering out. But the winter approaches rapidly and so I thought I'd make a start on the hardest bit... before SWMBO realised exactly how big it was going to be :). I have to say I am quite proud of my hole.. but I need to get on and fill it. Problem is I can't be home to accept deliveries, I need to be at work (I sort of managed to scrounge some extra days last week by agreeing to be on call over Xmas, but I am now all out of holiday till next Jan) and most places don't deliver Saturdays. So I can work from home some days but the logistics are complex! And I really only have weekends to work - those that are not already allocated to family stuff. So next weekend I hope to finish the shuttering (didn't get any movement on this this weekend as I'd hoped) and, by then, have ordered the ballast, sand, DPM, reinforcing mesh and insulation. I don't have room in the garage to work on the shuttering, it has to be done outside on the patio :(

So the following weekend will be preperation work and hopefully I can get a concrete pour during the following week - 2 weeks out. Then I have to wait at least 14, pref 28, days before I can start on the walls, but that gives me time to order them and the roofing stuff. Once all thats in place I can work on the inside through November and do some evenings so it'll go faster. I'll leave the external cladding and tidying as long as possible... maybe into next spring lol.

irving2008
02-10-2012, 06:49 PM
Well best laid plans etc....

The hole is still there, though its now doing a very poor impression of a swimming pool filled with porridge.

I was rushed with the digger and hadn't realised it was 100mm narrower than I needed and a little wasp waisted. Fortunately being relatively soft due to the water content I've managed to tidy up the edges and now its sides are parallel, vertical and the correct distance apart and I have dug the post holes for the 4 x 3 posts that will hold the retaining wall at the back. That'll be made of 4.2m long 225 x 50 (9 x 2) boards.

In the meantime I have finally completed the design of the steelwork needed in the concrete. Why do I need steelwork, isn't that a bit overkill I hear you ask? Well maybe if you dont care about cracks appearing in a couple of years time, but I want this to last 20years and still be stable and because its on a clay base and near a tree it has to cope with heave and shrinkage. The normal solution to that is to dig deep piling into the clay, about 4 - 5m deep or more and suspend the raft on top. Thats not an option for me, so the alternate is to build a concrete raft thats sufficiently strong to stand the lifting forces and also support itself if the clay shrinks from underneath a section of it.

The research into how to design such a raft has been interesting, there's surprisingly little info. A civil engineering graduate son of a friend said that it wasnt something they covered in his Uni course. But I have persevered and have now a design that meets the demands of BS8110 and I am confident it'll handle pretty much anything. It does come at a cost of 400-odd of extra steel but that was 1/2 the cost of the extra concrete needed in an alternate approach (not forgetting the need to dig the hole deeper as well).

It does make me wonder just how good a job the companies that estimated this work for me would have done. Yes they might have finished now, but the life-expectancy of the work would have been severely compromised. One wasnt using any steel at all ("not needed") and the other said "oh we'll throw some in if you want".

Here's a Sketchup of the steelwork... all 418kg of it!

7031

irving2008
08-10-2012, 03:16 PM
OK, so having stared at my swimming pool/hole for a few days, I tried to work in it this weekend... after an hour of struggling in the porridge I gave up. I now have some inkling of how the soldiers in the trenches felt about the mud! So i need to empty the water from the hole so it can at least have an attempt at drying out. I need a pump that can handle dirty water, can pump close to the base (a lot can pump down to 4", well its not much deeper than that in places) and can shift around 2500litres in a reasonable time... suggestions? or can anyone lend me one for a couple of weeks?

WandrinAndy
08-10-2012, 03:28 PM
Would it help digging a small sump hole in the middle from which to pump?

irving2008
08-10-2012, 04:44 PM
Would it help digging a small sump hole in the middle from which to pump?
Yes, I'd just about figured that idea out myself :) there is actually a sump at one end where i was a bit enthusiastic with the digger but there's a ridge to the other end so I'd have to dig (dredge? lol) a channel...

Peter.
08-10-2012, 06:32 PM
I'll see if we got a spare pump at work Irving, can't promise we have one spare but you never know. It'll be though but I have a transformer you could borrow also. If you had asked last week I could have dropped one round as I was working in Hendon this weekend.

irving2008
08-10-2012, 07:41 PM
Thanks Peter... Mocha has also offered, but its the logistics that always defeat these things... so the more offers the better - let me know if you have one...

Oh btw , heres the paddling pool of porridge... :(

7088

hmmm... not sure where to send the water... the nearest drain/sewer is about 10m or so towards the camera... it cant go left or back as thats uphill... and right means flooding the back of the neighbours garden.... so drain/sewer it is... so I'll need some 10m or so of 1.5" or 2" flat hose or whatever the pump takes...

Peter.
08-10-2012, 07:57 PM
You don't need 2" for that little amount, some 1/2" hose on a little hippo pump would clear that in 30 mins and easily keep up with any incoming. A 2" pump would drain that lot in probably 2 minutes.

irving2008
08-10-2012, 08:39 PM
You don't need 2" for that little amount, some 1/2" hose on a little hippo pump would clear that in 30 mins and easily keep up with any incoming. A 2" pump would drain that lot in probably 2 minutes.Thanks Peter.... I just know that filling a paddling pool with a 1/2 hose takes forever lol :)....

Web Goblin
08-10-2012, 09:15 PM
Small hippo would empty that easily and pump it 10mts to the drain. My small hippo can take a 40mm id hose. Empties my 2000 gallon fish pond in around 1 hour.

irving2008
11-10-2012, 12:22 PM
Mocha's Hippo is doing well .. three hours (limiting factor was the 1/2 inch hose cobbled together with duct tape) and it looks like this:

7108

need to move it to the back to shift the remainder...

D.C.
19-10-2012, 01:34 AM
If you are doing a lot of groundworks anyway you might to dump a load of tubing down there and do a ground source air pump.

irving2008
19-10-2012, 07:44 AM
If you are doing a lot of groundworks anyway you might to dump a load of tubing down there and do a ground source air pump.Thanks. Interesting idea, but the additional depth I would need to dig, some of the regs and the need for planning permission make it a non-starter...