My house is 80+ years old and the basement walls are sloughing off. The walls are about 18″ which doesn’t result in a structural problem. The rear wall and 1/2 of the side walls are below grade, as it has a walk out basement under the front porch. From what I gather, the sand used was unwashed river sand that contained a lot of organics and nutrients. A large river is three blocks from my house. This is a very common problem in my neighborhood. The walls also contain river rocks up to 1′ on diameter. The previous owner painted or skim coated the walls with some kind of fiber reinforcing paint like material. In areas without paint, the walls crumble when something is brushed against it and the area with the paint comes off in larger chunks. I’ve invited a number of “professionals” and they all have their own ideas, some don’t have any. One idea is to attache Delta MS to the inside of the wall then pour a 4″ thick concrete wall to sandwich the Delta between the old wall and the new wall. This will allow the water that “may” leak through the original to be transported to the gravel bed beneath the floor. This is a very costly solution 18-20k, which is a lot for a 6′ high basement. Any ideas would be appreciated. Thanks in advance.
Mark
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Sounds a bit like our basement. We have an 80 year old house with cement block walls that were then skim coated with plaster. At some point (I'm guessing in the 80's when they disconnected the gutters from the storm drains) the previous owners decided to 'drylok' the basment instead of properly regrading the exterior landscape.
We've since done that, but the lower 2' of the walls had 20 years of water pressure on them which slowly caused (from what I can tell) moisture migration which degraded the surface of the plaster and has caused it, along with the paint, to flake off small sheets.
It's pretty ugly and short of sandblasting, I'm not sure how I'd fix the wall itself. What we've done was to fix the water problem, knocked as much loose stuff off as we can, and added one coat of drylock just to hold what was left in place.
We're now putting up interior walls to cover the ugliness of it, as well as to add insulation and then finishing the basement.
What is happening also happens on a conrete block wall. There is a wetted side and the other side is the drying side.
The drying side ends up with an accumulation of salts that breaksdown the cement or block.
Painting or sealing on the drying side usually result in big chunks, in the wet areas, peeling off.
One solution is to stop sprinkling the other side of the wall or dig out the wet side and waterproof it.
An easier method is to stucco the wall. The stucco allows the drying side to deal with the moisture. It provide a new surface to allow moisture to evaporate without it breaking down.
Disadvantage is that it will be blotchy in color between moist and dry.
Sounds similiar to a problem shown on TV "Holmes on Homes". Fairly new house foundation was crumbling because too much water was added and it didn't cure right.
Solution was to dig inside perimeter, pin and add new footer. Then build block wall, spray foam insulation on old foundation wall. At top of new inside perimeter wall, non-shrinkable cement grout was used to hold up the house.
Sounds like you also need to insure that the outside drainage issues are all cleared up.
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Is the wall 18" thick or 18" tall?
Is this "sloughing" on the inside or on the outside?
Is the lot graded away from the foundation to keep it dry or does it allow water to drain or collect at the wall?
Are these walls built of rock, brick, poured crete, or....????
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The basement wall is 18" thick and 6' high. It is composed of river rocks (smooth rocks) with most being 1" - 2" diameter and the largest diameter is 8" - 10" or so. The concrete is breaking down in about 50% of the basement. There are no leaks as the ground slopes away from the foundation and the downspouts are all tied to dry wells 50' +/- from the house. A brush on application will not work since the concrete crumbles as it is touched. I was thinking of some type of spray emulsion or chemical and overlaying it with fiberglass sheets. Similar to Nuwall, which unfortunately won't work. Any Ideas?MarkIt is sloughing off on the inside...
Edited 11/23/2007 12:19 pm ET by Mark46
Probably a very slow degfeneration duew to moisture working through from outside. I don't know if there is an epoxy type injection solution or not
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The breakdown is due to using unwashed river sand that contained organics. It is very common in our area. Mark
Do not use an epoxy, paint or sealer. The wall is very porus and needs to breathe. Its breathing cannot be stopped and it include passing of moisture.
Stucco is the answer. It is trowel over the moisten surface and will let the moisture out.
Try this to test my method. Patch an area with stucco, paint and epoxy. The stucco (conventional type colored finish coat) will keep it from crumbling.
Painted stucco houses are the ones that peel and blister.