I have an unfinished basement where I would like to pour a Concrete floor. The house is built on a slight grade and the footings are not level. On one side the footing drops below the level where the concrete will meet the interior of the wall. This means that the concrete would end up against the wood framed wall. I am thinking that I should put 1.5 inch foam insulation between the wood framed portion of the wall starting at the footing and going up to the level of the finished concrete floor. Is this the right thing to do, or is there a better way of going about this. Thanks for your help,
House Slave.

 

I would look into some type of expansion joint.

 

The foam that you mentioned would certainly work as would most other expansion joint materials. I would also put a heavy gauge plastic barrier against the wall and extending out under the floor for a foot or so to ensure no moisture gets against the wall. You definitely don't want to have the concrete contact the wooden part of the wall especially if it's not pressure-treated material.

 

both have the right answer - use the foam + plastic

 

Thanks, I forgot to mention that I do plan on using a 12 mil plastic vapor barrior beneath the concrete sealed to the footing with a caulking type of adhesive. I will be drilling and epoxying rebar into the footings every 16". Should I take the plastic all the way up to the top of the foam or allow the concrete to contact the footing above the vapor barrier and below the sill plate so that the concrete can adhere to the footing? I plan on sealing between the foam and top of the footing with caulking. Thanks again.
House Slave.

 

why rebar ? unless there's a good reason you anticipate the new floor sliding out of position, i wouldn't,,, fresh conc will NOT bond to old conc UNLESS you prep the old + use a bonding agent,,, in any event, you don't want the new conc to bond - just let them be slightly friendly but NO bonding

 

What is the down side to anchoring to the footing with rebar other than cost. Living in a seismic zone, Southern Ca. I am hoping that when we fall off into the sea, that the house will go down with the ship in one piece.

 

same reason you don't anchor the backyard conc patio to the house,,, they're supposed to ' float ' independently