I have a monolithic slab on grade foundation. The 7’x23′ porch slab is an intergal part of the house slab. The porch slab is 3-1/2″ to 4″ below the house slab ,
How is the best way to add / pour concrete on top of the porch to bring it up level with the house slab. Thanks.
Replies
Form it up and pour over it. at that thinkness you shouldnt have any issues.
I'd think you'd want to bore holes in the existing porch and insert dowels.
you could
but why?
To eliminate any chance of the new piece shifting.
dont see that ever happening
but better safe than (very unlikely) sorry.
It wouldn't take much -- 6-8 dowels, probably, for 7x23, and you could get away with three. Pieces of rebar are obvious, but one could use old lag bolts or pretty much anything -- drill the holes about 3 inches deep, drop the dowel in, and then cover with concrete.
Note that these dowels would be vertical, into the horizontal surface. There should be no need for horizontal dowels where the edges meet.
Of course, another option, assuming that the space is going to be incorporated into the conditioned space, is to build up the floor with foam board and floor sheathing. The rim could either be treated lumber or you could lay concrete brick along the edge.