Waterproofing front basement rubble stone wall
the front wall of my brick row house in Ocean Hill – the rubble stone wall foundation in the basement – is letting in water – I am working on how to resolve –
1. clean out disintigrating mortar – and cement over the stones – smooth out and have a semi-finished wall which is now waterproofed from the inside – (does there need to be some type of paint on vapor barrier between stone and cement
2. Point rubble stone – clean out disintegrating mortar – repoint with (portland cement)
3. break up the cement in the front of the building – close to the wall_ dig down 10′ and waterproof stone wall from the outside – I did this on the back wall in my back yard when I first bought the building in 2014 – no one who has looked at the wall has suggested this solution.
4. One waterproofing company suggested we foam seal the front wall instead of cement.
2 & 3 are perhaps the more expensive solutions – can I safely get away with cementing over the stone – is there a reason I’ll need access to the rubble stone wall?
thanks very much for input and suggestions.
victoria.art.director
in General Discussion 1 weeks ago
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victoria.art.director | 3 days ago
to clarify – I’m not actually getting water coming through this wall – I’d like to simply regrout and my mason – and every mason who came through wanted to put cement over the wall – saying it’s the bes – I’m thinking it’s the easiest –
I am getting ground water in front of that wall – I can see it discoloring the concrete floor – I think the solution to that problem a french drain – if/when I want to invest – although i also think about pouring a cpncrete floor above it as well
Brownstone Home Inspection | 1 weeks ago
so victoria:
i think we spoke on the phone a few weeks back. i have read what you are saying and what cate said. obviously, the most expensive solution is going to be to dig up out front of the house and put a membrane on the wall from the outside. the membrane can be rubberized product or a liquid or mastic applied product. as water comes against this product it will push it against the wall and keep it there. this is called positive-side waterproofing.
the cheaper options will be negative side waterproofing as the water will come into the walls and push the waterproofing away from the wall on the inside. this creates a challenge in that the membrane or mastic must adhere to the wall or it will get displaced by the water.
there are several products for dealing with negative side water proofing. but what i have watched several customers do is this: clean the grout joints of loose matter and dust that could inhibit adhesion and consider a cheaper approach and start with hydraulic cement to fill the larger joints. Modern professionals will tell you that there are negative side epoxies that will hold better and everyone admits that some hydraulic cement will fall out over the years and have to be replaced. But initially, it will be the cheapest approach and if it works, you can stop there. Besides, a handyman can pretty much do it without reading a can of directions. I can coach you here as well.
If it were my house, I would start with the hydraulic cement and then if that did not work (if it held but leaked), I would leave it in place and begin using an epoxy-based negative side sealant (the epoxy will have greater adhesion than the hydraulic cement. I can get you the names of some of these. The reason I say to fill voids with hydraulic cement first is these products are specialized and it will cost a bit of money to fill larger voids with them (and some of them may not be thick enough to bridge gaps; there are silica thickeners that can be added to most epoxies).
I do believe you mention having a false wall put up in front of the stone (after some water proofing is done on the stone). Listen, I beg of everyone on this board, if you have moisture issues in your cellars, do not think that building a wall with some kind of membrane on one side of it is a solution to a problem like this; even if you put the trough in and had them drain to a sump and have it pumped out, it is still a bad idea. Why? You wish to be able to monitor the wall over time to be sure a leak has not resumed. You will also need constant air circulation so that damp air does not settle in pockets or behind false walls. The issue with this is, trapped humid air (say a rh of 65% or more will raise the moisture content of wood and if it goes above say 26%, thermites can thrive). For this reason, do not wall a damp basement up in a way that causes air to stagnate. Also, consider getting a dehumidifier.
Steve
Brownstone Home Inspection LLC
resident2 | 1 weeks ago
The best thing is to keep the water from the outside of the foundation wall before it seeps through the foundation.
The cheapest & easiest is to pitch the paving cement whatever in your front yard away from the house. Do not put in a flower patch there. Have tubs if you want a pretty front yard.
The next, more expensive if the first option does not work, is as you have been told; is to dig down the front of the building, exposing the foundation wall and selling it with Tar etc. If you are in a Landmark District this will require a permit or Certificate of no effect, depending on the style of your front yard.
Sealing just from the inside, will only be a temporary solution and the water still getting your foundation from the outside will make a deteriorating situation & a big mess…. eventually.
cate | 1 weeks ago
Hi Victoria. A few thoughts:
(1) We’ve repointed our rubble walls in the cellar from the interior a few times over the years to seal up holes (largely to keep out vermin) but AFAIK that has little to do with waterproofing.
(2) We had a terrible ongoing leak for years coming through a corner of the cellar walls we did everything to try to stop to no avail. Finally, when we removed the PermaStone covering the garden-floor brick and repointed the brick (outside), the leak stopped.
(3) Everyone says to make sure the concrete is graded so water runs away from the house. Is there any water source or pooling near the house, such as a drainpipe that doesn’t carry water away from the house, or water puddling near the house?
(4) Everyone always says that to waterproof a cellar wall, you must dig out the ground outside and waterproof it from the outside.
(5) I don’t have personal experience with them but people often seem to recommend using French drains to direct water away from the house.