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Odd crawlspace, top of footer is below slab, water seepage

coredaus's picture

Hey everyone--

house is 1963 ranch, basement is 1/3 crawl, then 1/3 full basement, then 1/3 (another) crawl. crawlspaces have rat-slabs in them (1-4" thick). each crawl is roughly 600 square feet.
In the crawlspaces, the top of the footers are ABOVE the slab-sloor, by about 5". So, usually when it rains water seeps through the construction joint where the footer and foundation wall meet. then this water runs onto rat-slab, pooling in the crawl. 
I understand now that the footer is typically buried below the slab, that way the water would just run below the slab.
So, the crawlspaces are frequently wet, inviting mold, not a good situation.  just to keep the basement RH under 55% takes two 70-pint dehumidifiers most of the time
I'd like to prevent water from coming in. options i can think up;

a) do exterior waterproofing; excavation, etc.  lots of work and $.  would be at least 120 linear feet of exterior wall.

b) add ~7" gravel on TOP of existing rat slabs, then pour a new slab on top of that.  effectively raising crawlspace floor to be above footer.

c) try to seal the joint between foundation wall and footer with xypex, koester, or something

thoughts?  anyone ever seen crawlspace built like this?  

My inspector missed this 'feature' when we bought the house...
thanks for any thoughts.

I'd probably try to seal the (post #215991, reply #1 of 1)

I'd probably try to seal the gap first and see how that works. Maybe some kick out flashing above the gap and some urethane caulk in the gap. If you can caulk it I'd follow with faom in the gap from the inside.  Photos of the outside and inside would help

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.