Advice needed re cellar with slight damp issue

Vindiesel

hi all

i work out in my cellar but it is rather dusty which affects my lungs/throat. I want to get it replastered as the area where the floor meets the floor has in places lost it's plaster i think as it gets damp when it rains.

The damp isn't bad. the plaster turns dark but there is no water on the floor or up the walls. However I can't replaster until it is sorted. Therefore I think I need some kind of damp proof course, would that be right?

If so, can anyone recommend a firm in the Mcr area? I also need advice as to how to get the air circulating down there. There are no air bricks and i don't think i can get any fitted as it is a cellar and below the house/an extension ie no access to outside walls above ground level. Is there any way around this?


Thanks for reading this

cheers

littlesnuggy

Vindiesel wrote: »

hi all

i work out in my cellar but it is rather dusty which affects my lungs/throat. I want to get it replastered as the area where the floor meets the floor has in places lost it's plaster i think as it gets damp when it rains.

The damp isn't bad. the plaster turns dark but there is no water on the floor or up the walls. However I can't replaster until it is sorted. Therefore I think I need some kind of damp proof course, would that be right?

If so, can anyone recommend a firm in the Mcr area? I also need advice as to how to get the air circulating down there. There are no air bricks and i don't think i can get any fitted as it is a cellar and below the house/an extension ie no access to outside walls above ground level. Is there any way around this?


Thanks for reading this

cheers

If you want to make the cellar properly waterproof and habitable, the best bet would be to get some quotes from contractors for installing a cavity drain membrane system. This is a membrane that goes across the walls (& floor) and allows moisture to pass behind it (potentially into a drain / sump chamber, but by the sounds of it you don't have that volume of water) and you can plaster on top of the membrane.

You'll also want to be thinking about radon gas... properties with basements are at increased risk of containing dangerous levels of radon, as there's a large surface area in contact with the ground for the gas to permeate through into the building.

Whatever you do, don't install an extract fan in the basement to try to improve the ventilation as these will often increase radon levels by sucking more gas in, and radon will do you a lot more damage than stale air (which, I agree, is bad enough - esp. if you're working out!)

Hope that helps!

gmgmgm

Vindiesel, I *think* radon gas is only relevant in a very small part of the country. This is one guide: http://www.ukradon.org/article.php?key=indicativemap

Frankly it sounds as though you simply have bad drainage around the basement. May be some simple fixes like digging outside or a sump&pump inside.

Vindiesel

hi all

pretty sure i don 't have a radon gas problem in my area (Manc). Also, i think the sump suggestion is perhaps a little OTT. Like i say, i don't even get any surface water on the floor so it;s not a major issue just that the room is really dusty and have just been diagnosed with asthma so it's a problem.

Wouldn't have thought the plastering would be a good idea as the bottom of wall gets damp but maybe i shuld ask a plasterer? ? Any plasterers around feel like commenting?


cheers :-)

dander

My understanding is that to make cellars into dry, habitable spaces they should be tanked - damp proof courses won't work because the cellar is actually in the ground.
I guess it depends how serious a job you want to do - If you want it to be a serious living space then I don't think there are many options other than professional tanking, but if you want to keep it as basically a cellar, but just try to limit the dampness a bit, you might find a paint on liquid damp membrane would help - but I imagine you would have to apply it to every surface in a cellar - floor and right to the top of the walls because you're below the level of your dpc - so even that could add up and maybe you'd be best off getting it professionally tanked anyway!

littlesnuggy

The radon maps showing 'affected areas' are irrelevant if you're talking about a property with a basement. The Health Protection Agency (whose data is used to make the maps) say themselves that high levels can be found in basements anywhere in the country. And it's for that reason that HSE require workplaces to have radon tests if they're 1) in an 'affected area' or have a basement work area and are anywhere in the country.

The British Standard for basement waterproofing (BS 8102) states that water entry into a basement is forseeable (even if it is largely dry at that moment in time) and so any 'damp' proofing carried out should cope with future water penetration.

Vindiesel

dander wrote: »

My understanding is that to make cellars into dry, habitable spaces they should be tanked - damp proof courses won't work because the cellar is actually in the ground.
I guess it depends how serious a job you want to do - If you want it to be a serious living space then I don't think there are many options other than professional tanking, but if you want to keep it as basically a cellar, but just try to limit the dampness a bit, you might find a paint on liquid damp membrane would help - but I imagine you would have to apply it to every surface in a cellar - floor and right to the top of the walls because you're below the level of your dpc - so even that could add up and maybe you'd be best off getting it professionally tanked anyway!

hi dander. thanks for your reply.

i don't want it to be a serious living space, just somewhere where i am more comfortable working out ie somewhere less dusty.

Can you elabrorate on what 'tanked' means?

cheers

Vindiesel

littlesnuggy wrote: »

The radon maps showing 'affected areas' are irrelevant if you're talking about a property with a basement. The Health Protection Agency (whose data is used to make the maps) say themselves that high levels can be found in basements anywhere in the country. And it's for that reason that HSE require workplaces to have radon tests if they're 1) in an 'affected area' or have a basement work area and are anywhere in the country.

The British Standard for basement waterproofing (BS 8102) states that water entry into a basement is forseeable (even if it is largely dry at that moment in time) and so any 'damp' proofing carried out should cope with future water penetration.

cheers for that LS. TBH i am not concerned about radon. Life is about risks and managing them (I work in insurance which revolves around managing risk).

in terms of the damp proofing, I might investigate danders suggestion re waterproof membrane/paint.

Bob_the_Saver

Did this,
Made the walls & floor stable with a cement coat to flatten off. Dried out as much as possible (used a dehumidifier) Tanked the walls and floor with at three perfect coats of bitumen specifically designed for the purpose. On the last coat threw dry sharp sand over it whilst the bitumen was wet. After a couple of days brushed off extra sand, 3 good sand and cement coats, this holds everything back.then plastered walls and carpeted the floor. Don't drill holes in it through your bitumen afterwards to fix things to the wall or floor and leave a bitumened un-cemented/un-plastered gap where it joints on top any other surfaces at the top. make sure you have plenty of ventilation and no LPG appliances (bottled gas portable heaters etc) heaters below ground level.
10 years so far and no penetrating damp through the walls or floor. You can fix a sheet of wood to the wall with expanding foam so as not to drill through the membrane. Did this and fixed everything to it, strong as houses.

PS. 'waterproofing paint' - forget it

dander

Tanked is essentially where you put a sort of waterproof layer inside all of the room - leaving absolutely no gaps at all, because if you do, then all the water will collect there. Google "tanking a cellar" and you should pull up some usefull information.

It wasn't a 'waterproofing paint' i was thinking of - it's called liquid damp proof membrane (just checked the can). I got some from wickes, but I wasn't tanking a cellar with it! http://www.wickes.co.uk/Liquid-Damp-Proof-Membrane/invt/241217
Sounds pretty similar to what Bob is talking about. I used mine under a tiled floor in a cloakroom which just drops slightly below my damp-proof course, so very different situation but it was very easy to use.

northwest1965

Bob_the_Saver wrote: »

Did this,
Made the walls & floor stable with a cement coat to flatten off. Dried out as much as possible (used a dehumidifier) Tanked the walls and floor with at three perfect coats of bitumen specifically designed for the purpose. On the last coat threw dry sharp sand over it whilst the bitumen was wet. After a couple of days brushed off extra sand, 3 good sand and cement coats, this holds everything back.then plastered walls and carpeted the floor. Don't drill holes in it through your bitumen afterwards to fix things to the wall or floor and leave a bitumened un-cemented/un-plastered gap where it joints on top any other surfaces at the top. make sure you have plenty of ventilation and no LPG appliances (bottled gas portable heaters etc) heaters below ground level.
10 years so far and no penetrating damp through the walls or floor. You can fix a sheet of wood to the wall with expanding foam so as not to drill through the membrane. Did this and fixed everything to it, strong as houses.

PS. 'waterproofing paint' - forget it

Bob - where did you purchase the bitumen from? We are just looking into damp proofing our cellar

Vindiesel - How did you get on?