Lally Column Footing Depth
Dave Keith is working on his home in Syracuse, NY. It's an old one!
"I need to know about footers for LALLY COLUMNS.
I am fixing an 1870's house, two story, water damage. I will be adding many jack post/lally columns to level up floors and shorten floor joist runs(some 18 foot).
Do the footers need to go 4 feet below basement floor or just a foot or what?"
Here's my answer:
Dave, I would assume the basement is heated or the air in the basement never drops below 32 F. If that's the case, the top of the footer just needs to be below the BOTTOM of the basement slab. You have no issue with frost heave in this situation.
When you pour the slab around the base of the column, you help secure it in place.
The footer should be at least 8 inches thick, 2 feet by 2 feet in size and have #4 rebar going both directions about one foot on center in the middle of the concrete.
Be sure the steel lally column is primed and finish painted BEFORE you cover it with concrete. Also, to keep the column from bending in a basement fire, fill it with dry sand after it's installed.
You do this by drilling a hole about 4 inches down from the top of the column under the beam.