Do foundations need to breathe?
Hi, I live in Saskatoon, Canada. Our climate is considered humid continental – warm summers and very cold winters. I need some advice quickly if possible as to whether it is okay to pour concrete up to the level of our foundation to grade water away from our house. Our neighbor is away while their newly built house is being landscaped. I came home today to find that their contractor had done prep work to put a concrete pad between the two houses to carry rain water out to the front of our properties and to the street. This is something we had discussed but not finalized. The contractor was planning on pouring the concrete 3-4 inches higher than our stucco siding (our neighbors yard is higher than ours). I rejected that plan. He said that he could pour the concrete to just even with the level of our siding and make a gutter on the property line. This plan will cover our foundation with concrete on this side of our house. I always thought that a foundation has to breathe a bit. Should I be concerned? The contractor is planning on pinning the concrete to the foundation of our 1950’s house. Is this a concern?
Any help would be most appreciated
Colin
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Replies
Colin,
The situation you describe is potentially concerning.
In most houses, the bottom of the stucco corresponds to the bottom of the wood framing. If a contractor is pouring an outdoor concrete slab level with your wood framing, splashback and capillary action from the new slab can negatively impact your house. Ideally, the exterior grade should be at least 12 inches lower than the bottom of your stucco.
Martin
Thanks for your quick response.
Colin
Per code you should have 6" minimum clearence between cladding and ground or concrete; but if it under cover, like a porch, then you are allowed to have 2" clearence.