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thepriusowner
11-01-2010, 06:53 PM
I have a question about waterproofing a foundation. I see on the Internet there is a product called DELTA-MS. It appears to be some form of polymer that is corrugated using stubs in order to leave an air gap between the foundation. This idea at first seems very good. You have a plastic that keeps the water away and at the same time you have an airspace to let any leaking water down to the weeping tile. I have a couple of problems with this product in my mind. First of all it is fastened to the concrete using nails or screws of some sort. These nails and screws will introduce leaks in the future. The good thing about the old fashion of using tar as waterproofing is that you can get one continuous seal. In my mind anytime you introduce and nail you are breaking the seal and allowing the possibility for water to break the barrier. Since a plan to build in a relatively harsh winter climate, any water that gets into a tight space in the foundation will yield a crack. With all of the fasteners for this product, there seems to be a lot of opportunity for just that. Second of all, if I were to use this product I would still have to turn the wall to create a barrier for moisture if it should leak and go down after the barrier in the design space for draining. This would keep the water from penetrating. I was also thinking maybe I should put Styrofoam on the outside of the basement for installation. Styrofoam is relatively water resistant and at the same time provides an excellent source of installation. This would have to go between this product and the concrete wall. Then I have to think about fastening the whole thing to the basement. Just wondering if anybody has done this sort of thing? Just wondering if putting Styrofoam insulation on the outside of the foundation is a good idea in the first place? But that is a separate issue of its own. To my mind it's a good thing as it would keep the water from freezing against the basement wall. This would make the basement wall relatively warm and comfortable, at the same time the product should keep the moisture out. Just wondering what people are using as a good source of waterproofing in cold climates. I'm guessing different products work better in the from climates.

I was wondering if somebody put treated plywood separated by a few inches of watch gravel that goes down to the weeping tile. Wonder if that would be expensive, and would it work. I would still have to put tar on the basement, but all the water that penetrates the treated plywood should go down to the weeping tile. Treated plywood would not rot out, but it would pass water. At least that is my understanding, and then maybe put some sort of waterproofing material for feet just underneath the soil around the top of the foundation to keep the water away from the gravel. The gravel with act like a source of double block and bleed. The plywood on the outside should keep the silt in the soil from clogging up the gravel, while letting water entered the gravel and drain down to the weeping tile. There might be some sort of paper that does the same thing.

Just think what you guys think of the idea?

ConcreteTreat
12-07-2010, 03:10 PM
I generally disagree with excavating the exterior of your foundation for the following reasons:

1: Expense/effort -- You have to pay someone to dig up the entire exterior of your home, which just about doubles the cost of the job. Alternatively, you do it yourself and you're doing twice as much work.

2: Disruption -- You have to dig up your gardens, porches, steps, walkways, shrubberies, etc.

3: Hassle -- It's ugly to have mounds of dirt in your yard, and a year later you'll need to return and regrade the soil.

I'm 100% for an interior French drain system and sump pump. Get a good submersible cast-iron one, toss in a good battery backup, and get a drain system that doesn't have that ugly 1" gap around the edges of the floor and you're golden.

As for the other questions:

Styrofoam: Would it be crushed over time by the weight of the soils? Why not use use spray foam on the interior and avoid the excavation?

Plywood: Treated or not, it would definitely eventually rot.