Know Anything About Concrete?

[HoneyBadger]

I'm thinking of adding a concrete wall or two in my unfinished basement. I have a new home and the basement floor is a floating slab (I think that's the right terminology). Are there any special considerations I need to take before, during, or after pouring the concrete? There is a limited possibility that the floor could shift a little over time. What is the best defense against this? How should I anchor the new walls into the existing concrete floor and walls?

Thanks in advance!

[gnihcraes]

Full sized walls? Floor to Ceiling? (like a gun vault?)

Walls should float with the floor if it were to move.

[HoneyBadger]

Full sized walls? Floor to Ceiling? (like a gun vault?)

Walls should float with the floor if it were to move.

8ft walls with a few inches to spare under the main floor trusses.

[Jamnanc]

The product you want at the bottom of the wall is surevoid. Basically cardboard boxes that squish if the slab moves. Might ruin some of the purpose of your walls though. If my guess is right.

[ChunkyMonkey]

Consider wood frame w/ heavy gauge sheet metal instead?

[ChunkyMonkey]

The product you want at the bottom of the wall is surevoid. Basically cardboard boxes that squish if the slab moves. Might ruin some of the purpose of your walls though. If my guess is right.

To keep it simple..anchor to the bottom but build it w/ its own roof 4 inches short of the basement ceiling (like a safe room), so you don't have worry about settlement.

[HoneyBadger]

To keep it simple..anchor to the bottom but build it w/ its own roof 4 inches short of the basement ceiling (like a safe room), so you don't have worry about settlement.

I was planning on leaving a few inches to spare at the top anyway, but I'm a little concerned because the slab has cuts in it (to guide cracks) and one of them is right in the middle of the room I was planning.

ChunkyMonkey, you're thinking in the right direction. I considered steel, but in my limited research, it seemed that concrete was easier to work with and had a better strength to cost relationship. I could be convinced otherwise... I haven't done enough research yet.

[newracer]

Use cinder blocks

[davsel]

To do it "right"
Bust out the floor where you want the new room.
Dig down four feet
Pour a 16" wide by 8" tall footer where you want new walls
Pour walls on top of footer
Fill in and pour floating floor inside room
Patch floating floor outside room

That 4" floating slab you currently have may not support the walls you want to pour on top without cracking.

[newracer]

I assume this would be to make some type of secure room. Why not use steel studs to frame the wall and then steel security mesh before the drywall? Then you could build a floating wall that is typical used in basements.