Details for exterior excavationless foundation insulation
I’ve been following the development of NorthernStar’s approach to exterior insulation using hydrovac trenching and poured closed-cell spray foam, and it seems it would be an ideal approach for our 100-year old deep energy retrofit project foursquare in climate zone 4 (Manhattan, KS). I’ve attached a picture of the stackup we are thinking of using on the foundation and walls, and would welcome any thoughts/feedback on the design.
We have a full basement with 6′ below grade. There is no footing drain on the exterior, though we will be replacing the existing basement slab and adding an interior footing drain, sump, and passive radon system. Gutters and good grading details have been effective at treating bulk water issues in the basement. The soil seems to drain well – last winter we had burst pipes while visiting family, and the foot of standing water in the basement drained away overnight once the water had been shut off.
Our thanks for any advice you can offer!
References to the excavationless exterior insulation approach:
GBA Detail Library
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