footings for posts in a basement

Will1987 · 04-24-2007, 10:24 AM

This is the same hosue as the other post right before this, but a different question.

They want some new posts put in to support the stairs going down to the basement. Its a sump pump type deal in the basement. I figured i'd just get some p.t. 4x4 posts and put them in concrete footings on the bottom, those premade ones. However theyre shaped kinda pyramid like. I usually put brackets down on things like that, like L brackets, but a pyramid is obviously the wrong shape for that. this isnt really a big deal question but I was just wondering if anybody had any recommendations for that. should I maybe pour footings instead, just right onto the basment floor?
I definitely dont want to just have the posts right on the basement frloor because its clearly a wet basement.

Thanks,
Will

glennjanie · 04-24-2007, 11:27 AM

Hello Will:
The proper foundation in a basement is at least a 1' square cut out in the floor, dug down to undisturbed earth (which you should reach in 1' or less) then poured with concrete to the top (flush with the floor). While the concrete is still wet you could take a 16d nail and cut a 1/2" deep groove around the foundation which you can fill with silicone caulk later.
An L shaped bolt could be put in the center and extending 3" above the floor as soon as the concrete is placed. That bolt would give you something to keep the posts centered; you could even drill a 1-1/2" hole through the post centered at 3" up the post for access to the end of the bolt and giving room for a washer and a nut to hold the post securely.
Glenn