[1wiseguy]

I have a sagging floor. I am going to support and raise it with a beam and jack posts which will rest on the basement floor. I am concerned if the weight on the jack posts will crack/break the concrete floor. The present jack posts in the basement go through the concrete floor and I assume are sitting on footings beneath. The floor is in good condition now. Will there be a possibility of the weight breaking the floor? Should the posts be on some kind of support pads?

 

[de-nagorg]

Yes increase the footprint of the posts.

I suggest a 2'X2' 1/4" steel plate, per post.


ED

 

[Nealtw]

Or cut an 18" square out of the concrete and dig down to 8" below he floor top and fill that with concrete.

 

[chandler48]

If the steel plates aren't practical for you, you can always cut the concrete floor out where your posts will be in a 2' x 2' configuration and pour in concrete grout to a depth of 12" or so. That will give support and won't affect the remaining floor.

Edit: Neal types faster than me.