I’m doing a basement remodel because of extensive termite damage. The existing walls are painted but not with a sealer and it is peeling in spots along with lots of cemented on mud by the termites. I want to silicone 6 mil poly to the wall to block any further water from getting to the new insulation and framing.
The customer is worried about mold going between the plastic and wall and suggests I repaint the wall. Since the present paint is peeling a new coat over it ain’t going to make it stick any better, and my thoughts are if mold is going to grow the poly will have little bearing on it.
The water problem is also being addressed outside with improved drainage.
Any thoughts on this or suggestions are greatly needed as I can’t start framing till either I and the homeowner are convinced on a solution.
Replies
I wouldn't let you do it in my house. I think the mold thing is a worthwhile enough consideration, at least. When we get crummy block walls here, enter the guy with the big wire wheel and the dust mask. Strip it all down. Clean, seal. You want some assurances that what's going on outside is going to do the trick. Downspouts, grading, etc all to get the water away. When the wall is clean and painted, if you're lucky, a hurricane will come through and water test the work for you so you know, then worry about the framing. If you have doubts, if the joints are splitting, then you have to consider tuck pointing or excavating outside so you can put a new spray coat on out there. Mold is getting to be a big part of the remodeling conscience these days, and when it gets in and the little spores start to spread, it can be gawd awful expensive to get it back out again. Obviously, I'm not standing there looking at this, but I'd be sure of the water diversion, ditch the plastic idea, and when things are dry and going to stay that way, do the framing.
Ok so what do you reccomend putting on the wall? I put UGL drylock on my own garage walls (raw block)and it's peeling at the bottom. I have no runoff problem, it is soil moisture causing the problem. The same moisture that allows ground loop heating to work. Your solution to dig a 10' deep tench to the footers and waterproof is admirable but exactly how after doing this do you gaurantee it won't leak through to the framing and insulation causing mold? My question is would the plastic cause the mold? I don't think so. My thinking is if it is going to occur the plastic will encapsuleate it keeping it from the framing and insulation.
I have never seen a masonary wall below grade that didn't show water penetration.
The differance in the slab scenerio is that you are not encapsulating but rather providing a barrier between the ground and your slab/ structure. In the basement scenerio you are providing a barrier within your wall/ structure. You are no longer keeping something out but instead segragating it until it has reproduced enough to swollow the basement.
Seal the foundation walls from the outside - after they are dry. Otherwise you will be encapsulating the moisture within the walls. This ain't easy in the fall. Then apply a waterbarrier to the dried out wall exterior. Be sure the dainage around the foundation has 6" crushed stone and perforated pipe which leads to daylight. A layer of fabric goes over the stone allowing water but no dirt filtration. If you don't have the required slope to find daylight you have to dig a drywell. Do a search on drywells. Someone recently posted an excellent explaination of what they are and how they work.
I would leave the interior side of the wall uncovered for the winter. The heat of the house will help further dryout the wall - moisture which would never have found it's way to the exterior side. In the Spring you will know that everything is or isn't dry. If dry, most molds will cease being active. You may be able to find a fungicide however they may be more toxic than the mold. More research.
Once the fungi is dormant, fur out the wall and apply a vapor barrier over the new studs. This is to prohibit moisture from within the basement to come into contact with the fungus stained block wall. If using a Tyvek type material, print side facing you. Be sure to seal the top and bottom plates with a continuous bead of silicone.
If there were/ are termites and moisture is coming via the rotten sill plates you have serious recontruction issues. If your concern is about water coming in through the framing that's a horse of a different color. Nothing to do with ground water. Your sheathing has failed. Be sure it's a top down issue or a bottom up issue. Probes through the GWB on the interior side of the exterior walls should give you this answer.
Piffins solution is as good as any. Costs aside, I'm in favor of excavating. I don't know where you live and am aware soil conditions play a role in not only how much water is in the ground but how much stress is on the wall, but I'm on the other side of the coin here. It's fairly rare for me to see a basement wall that shows water infiltration. The most common issue I see is in older homes with block, the block joints fail and the wall bows under stress. Then we come in with steel I beams to shore it up as a cheaper fix, or excavate and replace the wall as the more expensive alternative. Don't think I'm trying to flame you here. I just disagree with the methodology. I don't think the plastic would work, I think the potential is there to create a breeding ground for mold and spores, and I think doing so only sets you up for legal troubles down the road. But hey, it's your job.
Thanks for all the input. I reseached this and made some calls and solved the problem to both my and the customers satisfaction.
Thanks again.
If the water problem is taken care of outside whjere it should be, you won't need the plastic or anything inside. I wouldn't have it on my house either.
What you can do is to seal with a paintable slurry from Thoro and then plaster or smooth stucco the insides.
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No can do the wall is 30' with electric, tele, and cable in it. The moisture is not running water but more dampness found below grade. Very similar to a crawlspace or under a concrete slab. That's why I'm thinking poly covering it.
If you poly cover dirt in a crawlspace or under concrete does this promote mold growth?