I’m building an 2-story addition and would like to make use of an existing 26′ x 18′ slab (6″ and rebar). I would like to use block walls for a full basement on the slab. The walls would then be backfilled approx. 5′ (frostline here is about 40 inches).
Any ideas or comments regarding the connection of the blocks to the slab or on the suitabilty of using the slab as both a floor and a footer?
Replies
I would make sure that the footer under that slab is deep enough to carry a two story wall. 10 to 12" at least. IMHO
As far as the connections of block to slab go I would epoxy 2' peices of rebar every two foot in to the slab, get them into that slab about 6" and make sure the holes are good and clean so you get a bond. Make sure your lay out will center the rebar in the holes in your block.
Good luck, Dave
Dave
Edited 3/29/2002 2:45:05 PM ET by DAVE_MASON
Thanks for the reply Dave. Do you think I could have a water seepage problem at the slab - block joint? There will be conventional drain tile installed around the slab's base but I'm wondering if that will be sufficient protection (in addition to parging the block wall).
Proper grading, elimination of roof water with drains and conventional footing drain will usually take care of it. There is not much you can do about that joint, you can try but lets face it there are bound to be small fissures that water could get through. if not right away then over time. If a high water table is the problem then consider a properly installed sump pump.
But definately check out the thickness of the footings under that slab.
Edited 3/29/2002 4:36:03 PM ET by RICHDES