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Concrete foundation for a basement

Concrete foundation for a basement

Concrete foundation for a basement

I am getting ready to build a home in Kentucky.  I have done most everything else except for a basement/foundation.  What size footer should you make for a house that is sitting on a 8'x 8" block wall basement.  Or would it be more economical to go with a poured wall?  Then after the walls are up, what should be applied to the exterior for water sealant?  

RE: Concrete foundation for a basement

Your footing size will depend somewhat on local soil conditions, but will likely be in the 24 inch wide by 12 inches deep range.  You should use a footing whether you decide cast-in-place or masonry walls.

As for waterproofing, remember this is your best shot at getting it right...after you are in the house, fixing a bad waterproofing job will be expensive and a royal pain!

I would start with the footings and then the slab. The best waterproofing you can get is coal tar, followed by asphalt.  There is nothing on the market that compares favorably with a hot applied, built-up waterproofing just like a built-up roof.   There are many pre-made materials on the market that are in a "peel and stick" form.  Some of these are excellent, some are pretty bad.  The best I've worked with is Kopper's Bituthene.  These are obviously more convenient and easier to place than the built-up system.  Be sure this is placed on a cleaned surface only.

Anyway, whichever system you select, make sure the bottom and walls are sealed together.  I don't know where your water table is in your location, but if your footing is ever below the water table, this joining of the waterproofing is critical.

Don't bother relying on just an unreinforced coating for adequate waterproofing below grade.  This won't work for the long term, no matter what the guy selling it says....again, you don't want to have to do this twice!  Also, there are a couple of systems out there that rely on reinforcing tape at corners and joints and just a coating everywhere else.  These are no better than just a coating.

Good luck and do it right the first time!


RE: Concrete foundation for a basement

Thanks for the advice Ron.  Where would be the best place to get coal tar and how hard is it to apply it?  I definately want to do it right the first time because this is going to be my home.  Thanks again..

RE: Concrete foundation for a basement


Please follow up on Ron's advice to the fullest!  You can't underestimate what a little work and material can spare you later down the road!  And your in the perfect situation by not having some contractor tell you what he wants to do...he's not living there; you are!

RE: Concrete foundation for a basement

The coal tar I referred to is a hot applied roofing material.  Most roofers can do either coal tar or asphalt, though many of them don't know how to properly do below grade waterproofing.  Find one who has experience in waterproofing as well as roofing and you should be OK.

Good luck.

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