I have a cellar which has damp wall, not wet, just damp. The existing white paint is coming off in places and there is a white powdery deposit.
I would like to make it into a pleasant room, so need to tank the cellar.
Can anybody recommend any systems?
Thanks
Andrew
If you want it habitable, then you'd need to vent it and seal the walls from the outside to stop water penetration. If you want it pleasant to store things is, then get old pallet boards and lay them on the floor. Cover these with flooring grade chipboard to make a decent walking surface.
Paint all the walls with an Alkaline Resistant under-coat paint after brushing, wear a mask, most of the efflorescent salts off. With a couple of good coats of the AR under-coat on the walls, you should be able to paint a good quality emulsion, not a gloss, on the top to make it all look pretty.
Tanking is an uncertain method, changes the walls from damp to saturated, is bound to fail sooner or later, and when its cement onto victorian bricks does considerable damage.
Try a dehumidifier instead. Lime plastering the wall will continue to allow it to dry and make it all look good.
NT
It may need nothing more than some proper ventilation. The wall temperature will be lower than the rest of the house and damp air will pool there causing condensation. Try running a dehumidifier in it for a month - if that works almost certainly improving the ventilation will work.
Thanks for all the suggestions,
I forgot to add that there is a window in the cellar which has been open for
6 months, so it is very well insulated. It is definately penetrating damp through the walls.I feel I have no option but to stop this damp getting through, but how?
A celler had been converted to a washroom by a basic tanking method of adding sika1 waterproofer to the render mix. It was then just rendered around and the floor screeded all using the water proofing additive. there is also a manhole in the same room. The manhole hasn't got the correct cover on it. The room was ventilated via several air bricks. The room was dry but always smelled damp.Anyways a few years after this was done a water leak developed from the out side mains, leaking into the cellar wall. The waterboard supplied a dehumidifier which was the size of 3 drawer office cabinet (on its side). this had what must have been a 10 gallon drum underneath. This filled up in about 3/4 days. It was there for about 6 weeks. It wasn't emptied regularly and would spill over hence taking longer to dryout the room. From then on the room hasn't smelt of damp. so a dehumidifier might just work but you could also consider rendering with something like sika1 ( it was the architects suggestion to use that product).
It isnt possible, thats the point. Unless youre wiling to dig down outside and apply a membrane there.
You will need to handle the damp practically - if its to be a success.
NT
The message from "Andrew Barnes" contains these words:
Have you garden ground outside? If so, start outside. JCB, deep trench to below level of found and at least three feet away. Field drain in bottom, gravel and fill. You probably want it further away in order to give the machine space to operate. Drain water away to a soakaway if you can do that, if not, take it to a sump and pump it.
Even reducing the amount of wet ouside will make a difference.
I'm assuming you don't want to go to the extent of exposing the outside of the wall, though that's the best way.
Tackling it from the inside, get a dehumidifier going to soak as much water out of the wall as you can. Beg, borrow, or hire a setup for installing an injected dpc and make sure the holes are drilled as vertically as practicable.
If existing concrete floor is sound lay polythene DPC right to outside walls. Lay 2" insulation board on top followed by 2" concrete floor but stop both 6" short of outside walls. Turn up the loose dpc and form a concrete drain channel 3" wide and 5" deep immediately adjacent to outsdie walls, draining into a sump -- concrete side of drain channel to butt against upstand of the DPC.
Keep that dehumidifier running and note how much water you're getting out of the atmosphere down there.
If you tank a damp wall without drainage ... it will probably become wet eventually.
My tanking system is similar to that of a cellar type system. It's inside rather than out. See my ramblings here
HTH,
Alex.
Nonsense. Next time you go into the basement of a shop in one of those trendy restoration areas, ask yourself how they got it so sweet smelling and dry. I can assure you they don't dig up the street.
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smelling
the point sir, which was already made further up thread, is that it doesnt last. It also damages the soft bricks most Victorian houses are built from.
NT
I'm trying to sort of do this by installing a pair of lintels through the walls then injecting liquid membrane onto the outside of the buried walls. I'll let you know how well it's worked next winter :-)
How will you get to the outside of the buried walls? I have seen tanking done solely from the inside. Not quick and certainly not cheap but the results were impressive. A smelly *wet* basement in Notting Hill converted to a fashion showroom in about 10 days. Is this in the best interests of the building? Well, put it this way, I know a beautiful commercial listed building in East London which is quite literally falling down because it cannot be economically restored. Great for the pigeons and the flies, and the bureaucrats
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Get to the problem at source. Dig up around the foundations in stages, and fill with hardcore. This keeps the water away from the walls . While you are at it put insulation against the walls to eliminate heat loss to the ground. Around the walls have concrete on ground sloping away from the walls. This stops water getting under the ground near the walls and takes water away from the walls when drained. If you cannot ring the house with concrete, put thick poly sheeting under ground from the walls slanting away from the walls (do this as a matter of course anyhow). This will drain top water away from the walls. In the US some put insulation about a foot under the ground slanting away form the walls, about to as far as you can go. This keeps the ground under very warm, and les influenced from the cold surface earth colled by the cold air above.
Then paint the cellar walls with about 2 to 3 coats of Sythaproof. You should be fine for ever after that. You may want top install a heat recovery and vent system to permanently vent the place. There are a few web sites around explaining this. One is a council in North Wales, either Clywd or Powys.
The materials are not expensive, but the labour is and doing it yourself a little time and patience is needed. Well worth it to basically add on an extra habitable floor, as that is what you are doing. Far cheaper than an extension and a large cold bridge is eliminated making the house cheaper to heat. You could do it all in a summer and then have an extra floor to your house. Try doing an extention floor to the top of your house in your spare time during a summer.
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