Basement tanking/ Dampproofing

[alprod]

Hi,

I live in a 100yr old mid terraced house with a large basement which is really damp. I think the reason is due to penetrating water through the old brickwork, its pretty bad in some places. It's really the front and back walls that are the problem.

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• alprod
• 8 Jul 2008
• 2

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• alprod
• 8 Jul 2008
• 3

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• alprod
• 8 Jul 2008
• 2

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• alprod
• 8 Jul 2008
• 3

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• alprod
• 8 Jul 2008
• 2

I had a specialist in tonight to discuss tanking and he advised the menbrane method on the front and back wall only and then resetting a new floor. All in this will cost about £4000 which is alot more than I expected and i'm also concerned that the menbrane style of tanking does not address the issue of damaged brickwork and missing mortar.

So i'm thinking od doing the two walls myself using a cement based tanking method. I was planning on needlegunning down to the bare brick, pointing the walls then slapping on the cement tanking. Hopefully this will stop alot of the water penetrating in and therefore reduce the dampness alot.

I've read that cement tanking sometimes has problems regarding pressure build up, but as i'm only doing the two outer walls (back and front of house) i'm hoping this wont be a problem.

What do you guys think, would this be a good idea and would it be worth the time and effort or should i just accept a damp basement if i'm not willing to pay the big bucks for the menbrane. The damp isn't a huge problem at the moment and is pretty standard for the type of house in this area. It just means my basement is pretty useless at the moment

Thanks for any advice.

 

[emphasis303]

what about rendering the wall with a liquid waterproofer mixed in? Not 100% sure and havent tried it so maybe others can comment on this

 

[JohnD]

repairing and repointing the brickwork is a very good move

however, putting an impervious coating on the inside of a damp basement is liable to result in it being pushed off by water pressure.

An alternative approach is to line the insides of the walls with a waterproof membrane with battens. Water will still pass through the wall and drip down to the floor behind the membrane.

You lay a floor with a slight fall and a gutter round the edge and lead the water to a sump, which you pump dry with an automatic pump (or lead downwards to a drain if such a thing is possible)

On top of the floor you lay a sort of paving stone called a drainage tile, which has a gap underneath allowing water to drain towards the gutter.

So everything outside the membrane and the floor tiles is wet, but inside is dry.

You then lay your floor on top of the drainage tiles, and redecorate on cladding on the dry side of the membrane.

You could do most of this yourself at lower cost.

This method is actually used on underground structures made in top-quality modern reinforced concrete, since it has been found that even the best underground structures are liable to water penetration, but this method can cope with it.

Even cheaper, if it is just a bit damp, is to repair the walls and add lots of ventilation, so the moisture dries out faster than it arrives.