Change of plans: basements

[Rogue]

1) Ideally in a workshop you keep the temperature above 5 celsius, as that stops condensation and you leave a de-humidifier running to remove the water from the air to ensure you don't get condensation on colder metal surfaces, leading to rust. Since your room is ventilated that could be difficult, or at least very inefficient.

But as it forms part of the house (the living room is seperated literally by floorboards and carpet) is it as likely to drop that much in temperature compared to a seperate building like a shed? This is one of the things I'm wondering.

By the way I was hoping to give you a chunk of my money last year, Jonathan. Unfortunately I had to give it all to the roofers to fix what turns out to be a DIY-dormer job by a previous owner that led to the ceiling in our bedroom coming down! Part of the reason why I'm moving down the project down to the basement in fact :o I hope you managed to find plenty of beer money anyway!

Edited to add: Come to think of it, as the equipment will be in an enclosure that is airtight enough to reduce sound transmission, I guess the baffled airducts could be closed when not in use and a dessicant left in the enclosure. Hmm.

[Treemonkey]

I have the exact same problem! Although my cellar has a brick floor and there has been flooding before. It's been a massive job...

Firstly the walls were covered in some impermeable paint which was allowing moisture to build up behind it, causing condensation on the walls. I have spent several weekends removing the paint, and the room has dried out considerably. Next job (still ongoing) is lime washing the walls, done a few coats this helps the masonry breathe properly it takes 4+ coats for a decent finish.

Also before getting to the brick floor it was originally covered in 3-4 inches of mud / wood which had disintegrated which needed digging out... I've scraped out between individual bricks and will be brushing mortar between them over the weekend. When I inherited the cellar all the vents were blocked so It is still drying out in places. I may need to add a pump at some point in the future, in case of flooding.

There is a problem with condensation although any tools hung up are fine, just anything on the floor when picked up has water droplets on it.

So I can recommend lime washing your walls!

[Rogue]

...Firstly the walls were covered in some impermeable paint which was allowing moisture to build up behind it, causing condensation on the walls. I have spent several weekends removing the paint, and the room has dried out considerably. Next job (still ongoing) is lime washing the walls, done a few coats this helps the masonry breathe properly it takes 4+ coats for a decent finish.
...
So I can recommend lime washing your walls!

Ahh, I had heard comments made elsewhere about moisture issues and paint. So I take it that the key is to use a paint that can let the moisture pass through? 4 coats of limewash should take up a few months but it's all for a good cause and at least my time is free :D

[Treemonkey]

Yep lime wash is breathable and white so good for lighting :P

Before in the dryer part of the my room you could feel moisture on the walls around 4-5 feet up, now the worst wall (external one) only feels damp at the bottom 1-2 feet but it is improving. I think when there is a couple more coats of lime wash it will spread the moisture out so with some extra ventilation / air circulation I hope it will improve.

By the looks of your pics the walls have the white flakey stuff efflorescense so its probably best to go for a breathable paint.

I am also pondering making a simple air heat exchanger for the vents to help improve the temperature, that will likely be a job for next autumn/winter.

[WandrinAndy]

To my mind currently, the biggest (or smallest) problem is that the height from floor to the bottom of the joists is approx 170cm - while I'm approx 185cm tall I'm planning on having everything at a good height for working seated!

I can't help thinking that you will have to don a crash-helmet before going down there.... I know that I would.

[Rogue]

I can't help thinking that you will have to don a crash-helmet before going down there.... I know that I would.

I've already taken a few good knocks today. I'm used to it though - the old workspace had sloping roofs and two bloody great beams at exactly the wrong height. I kept forgetting they were there and walking into them. I think I actually knocked myself out once...

[Swarfing]

I used to srt a lot of this stuff out in a past life. To save you a ton of hassle i tank the whole lot out. You have signs of moisture on those walls and they will bite you later. In terms of ventilation, i will assume you have modern central heating in the house. You can minimise that a bit and get away with a couple of air bricks either end of the house. The breathable membrane is this stuff

Tanking Membrane 20m | Twistfix

you can use silver sided plasterboard straight over the top in battens and some thin insulation behind it. As for the floor above i would go for some insulation in between the joists and plasterboard over the top of that. The floor could be quite expensive if you want a good job done where you will need an epoxy dpm once you key the surface which would allow you to use a waterproof latex based leveling compound which you can add any type of covering you like.

Hope this helps

[Rogue]

By the looks of your pics the walls have the white flakey stuff efflorescense so its probably best to go for a breathable paint.

I gave the whole thing a quick once-over with a stiff brush and cleared the detritus from the vent, even that little bit of work makes a heck of a difference! There is some very clear efflorescence on part of one wall (just the top part though, the bottom part looks very clean. A lot of the white stuff appears to be some kind of flaking paint, it's almost like it was given a very light wash of something.

Thanks to the many fine suggestions from people both here and in PM! This shouldn't take me more than four or five years to complete :)