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Waterproofing stem walls in a slab on grade foundation

carl_f | Posted in General Questions on

Hello All,

I am detailing out the foundation plans for a 1 level modern ranch with a slab with concrete wall foundation (similar to the attached pic.)

While I have plans to seal the foundation to sheathing (probably with Prosoco’s R-Guard Joint & Seam Filler) as well as doing other measures including 3-4″ of EPS foam under the slab (2″ on perimeter), a 10mil Vapor Barrier, the use of  EPDM Gaskets as sill seals, I’ve not found any information one way or another on my need to waterproof the exterior of the stem walls.  I will be incorporating rain screens, french drains and be sure to divert all gutter outflow away from the building.

I’m on a low slope lot with no water issues and am in climate zone 4. (Central Kentucky).  The slab will include radiant..

To me it wouldn’t make sense to add a waterproofing measure to these stem walls, but am I missing something?   

Thanks much!


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  1. carl_f | | #1

    Interestingly, a link to a similar question posed in February showed up as a recommended link after I posted this question... even though I did search on this issue :-) Looks like I'm good with not doing anything, unless someone has additional thoughts...

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