New Construction DIY Foundation Waterproofing
For better or worse I am undertaking GCing our new modular construction pretty good house this spring/ summer in central MA. Part of this endeavor includes doing a lot of work ourselves in order to keep it “affordable”. We’re likely having the foundation poured in the spring, and giving it a month to cure before the modules are set. We will have a full basement with the following: interior XPS insulation, a studwall with sheetrock, subslab insulation, vapor barrier, and a perimeter drain that drains to daylight.
The foundation and site guy have told me that all I need to do for waterproofing the foundation is to roll on some Home Depot tar damp proofing on the foundation exterior and I’ll be good. With the amount of rain the region has gotten in the past year, and number of people I know who’ve had wet/ flooded basements, I’m thinking I should do better than roll on tar.
I’ve been looking at membrane style waterproofing products, but I don’t have any real feedback on what works, what is affordable, what is easy to install, etc. Does anyone on here have a system they recommend, that can be installed by 2 or 3 people, and won’t break the bank?
Much appreciated,
Isaiah
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Replies
this risinger video shows a pretty bomber system. even if you don't use their products the sentiment with all of them still applies. You don't want hydrostatic pressure on your wall and so need to give it a place to go.
https://www.youtube.com/watch?v=r4GdEJal8KM&list=PL677A300A4A7AF125&index=11
Tar can work as a budget option. Wear Tyvec suit, nitrile gloves and boot covers. It does not come off anything it touches.
Your most important step should be an exterior dimple mat that terminates into exterior footing drain in a gravel burrito that drains to daylight or a sump pit.
Tar and dimple wrap with good drainage at the footings is probably the best value solution. Spray on coatings tested and certified for hydrostatic head is a step up. Peel and stick membranes are expensive and often require a primer. I'd be worried about wrinkling and puckering of the membranes at corners and the footings creating channels for water.
Good to know that tar is acceptable. This sounds like the route I'm going, with a dimple mat wrapped down to the perimeter drain. Does the dimple mat need to be brought all the way up to grade? Or would terminating it a couple feet below grade work? Any specific products that people recommend?