I have three columns to support lvl beams under an addition and have a question about proper rebar layout for each (identical) footing.
All specs are already checked by engineer, but there is one area I'm not clear enough. I'll be doing this myself and the engineer is away. I cannot wait due to the other deliverables on the project.
Each column will be below the frost line, 30".
They will be poured 4 square feet by 1 foot high.
A cinder block column of 24"x24" will come up from the middle of that footing to about 7-8' to hold a 4 combined lvl beams to support the weight.
Number 4 rebars will be used in the footing & will come up with the cinder block.
Please help me on how to layout the rebars, such as spacing, how far from edge, from soil, how to come up to the cinder block, etc… All this will be inspected by the county prior to concrete pouring.
Thank you!
Best Answer
Keep the rebar 3”” from the bottom of the footing and 3” from the edge of the footing.
I’d install the #4 bars 8” oc each way. (You’re not concerned with flexural bending of the footing, because the column on the footing is so large 24”x24”).
I would run 4 - #4 rebar vertically in the column and install 4” hook (90 degree bend) in each rebar and extend it into the footing 8”. Make sure the vertical bars are about 1” clear from the edges, so concrete can encapsulate the rebar.
For that height of column, I’d use #3 ties at 12” oc. (#3 rebar you can bend by hand.)
I don’t know what you’re supporting (how much load), but that will support about 30 kips at each footing, unless you’re located in a swamp, like me. And the footing will weigh about 7 kips (dead load) each.
Keep all rebar down 3” from the top of the column.