I have a French Drain in my basement (Small canal along the basement walls). It still has the styrofoam in the canals along the wall.

Should I remove the foam from the canal in order to have a more effective drain?

Also I plan on finishing my basement. Can I put the walls on top of the french drain or should I offset it by several inches? Will metal studs work better just in case there is moisture that will run through the drain?

Thanks!

 

I would use pressure treated lumber and a construction adhesive to attach plate to floor. The reason for that is, if you try hammering near the edges of the french drain, even if the cement is three inches thick, you might crack the cement. That's why it's advisable to keep the wall away from the french drain. The styrofoam was put there to form the french drain and apparently there isn't a moisture problem because it was never taken away.

 

Thanks.


Should I then remove the styrofoam before finishing the basement walls, or does it not matter?

I have had a couple contractors in and they both said they would nail down the walls to the concrete slab. They will probably use a nail gun to do this. Should I be really concerned about the potential of cracking and mention something to them?

 

If you're going to put up the wall and enclose the french drain, then it would be advisable to remove the styrofoam. But I would tell the contractor to do it when nailing down the plate. If you ever seen these nail guns they use to nail into cement, they actually use a cartridge to shoot the nail. And there are different types of cartridges for different types of applications. In some States, you have to be licensed to use that type of nail gun. If you're a licensed contractor, it's not difficult to get this licensed. All you have to do is show you know the use for the different types of cartridges.

I would show my concern about cracking the cement being so close to the edge of frech drain. This would caution the contractor from over nailing the plate and using the right type of cartridge for that application. If it were me, I would leave the styrofoam there until I finished nailing and then remove it. In either case, the contractor and I am absolutely certain, you're going to check out that floor after the plate is nailed down.