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(n) pad inside existing residential S.O.G.

(n) pad inside existing residential S.O.G.

(n) pad inside existing residential S.O.G.

Hi All,

I need to introduce some interior pad foundations inside an existing residential remodel. What are some best practices with respect to breaking the vapor barrier?

I do not know yet if there is a vapor barrier but assuming there is, the installation of a new pad will break the barrier. Could this be sealed up during the new foundation pour say in two phases? First pour being the thickness of the new foundation. then phase 2 to include 2" of sand under new vapor barrier under the new s.o.g.?

Or is breaking the vapor barrier for such a small area (say 3x3 feet)not considered much of an issue?

Thanks all for your feedback and expertise

RE: (n) pad inside existing residential S.O.G.

Correct me if I'm wrong, but you want breach the slab and existing vapor barrier to set new footings? They way I do it can be summed in one word: carefully. Also, I don't pour footings on top of the existing barrier. Make your 3x3 opening and remove the rubble, taking great care to not shred the existing barrier. Once exposed, try to slice it corner to corner, and pull the 4 triangle flaps back and secure. Excavate your hole. Cut and attach new barrier material to the existing flaps (trimming as needed) to create square flaps instead of triangles. Right before the footing pour, tape up the interior corners of the barriers (think of it as recreating a paper bag from a bag that had its four vertical edges sliced open). Pour your footing up to the underside of the existing slab. Set your post (if it is a post). Re-cut the barrier and snug it up to the sides of the new post, and re-tape it all. Pour the topping slab after the footing sets.

RE: (n) pad inside existing residential S.O.G.

Thank you PG67,

Would you have any resources you could direct me to look into about this topic? This has been a gray area to me for some time and want to make sure i have my bases covered

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