Change of plans: basements

[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]

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
...

Once I managed to stop staring at your avatar, the rest of the post was very helpful

"Modern" is relative; when the British Gas guys do their annual check up on the boiler they ask if they can send the younger engineers around to see a "rare old classic that they can't believe is still running."

The basement does not extend under the entire house so airbricks would only be viable for the front wall, making unassisted airflow through the basement problematical I guess. Interestingly, the "major" efflorescense was confined to a small area at the back of the basement, which lines up with where the front room (wooden floor) ends and the back room (concrete floor) begins.

A chat with someone earlier reminded me of the following information that may or may not be useful.

First, the three houses at this end of the terrace have some kind of ventilation link through their basements that seems to be by design, possibly to compensate for the lack of front-to-back in the individual basements? The house two doors down had a fire recently and when it was put out the firefighters positively pressurised their basement to force the remaining smoke out, causing it to escape out of the basement vents in front of all three houses.

Second, the neighbour had an issue with a burst waterpipe that flooded all three basements (up to about a foot) roughly two years ago. It was resolved and the water pumped out, but nothing else was done at the time.

It looks like there was some ceiling in the basement at some stage - in fact the rafters/joists/whatever they are called are full of nails that need come out before I impale myself. Putting in the ceiling/floor insulation and putting up plasterboard should be within my ability. Skimming it might be an education, though! My concern was a comment I heard elsewhere that you needed to let air get to the floor. I have no idea why and bow to greater wisdom (ie you lot).

Another point I've realised is that our gas and electric come in through the basement so any work will have to be done around these. Not sure if that's something to pass on to a contractor for my own safety and my wife's stress levels!

My inspiration comes from looking down into the basement and thinking "I wonder if I could fit an X3 down those steps?"

[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 :)