Basement Framing Question

epeterson777

I am framing my basement right now and have run into a snag. I live in Colorado and we have to have "floating walls." Basically I have a plate that runs along the floor, then a gap and then the wall which attaches to the ceiling joists. There are large 6 inch nails at the bottom of the wall that hold the bottom plate to the floor plate, they actually can hold up a lot of weight before the wall will start to slide down on them.

With that said my problem is that I need to put up the bathroom wall and it will run right underneath a heating duct which means I can't directly attach the wall to the ceiling. Is it acceptable/legal to build a soffit around the duct (which I need to do anyways) and attach the wall to the soffit (like in this picture)? The wall on the left by the pipes will sit in front of the pipes and since the steel beam is there I will probably lower the entire ceiling for the bathroom similar to this picture.

Should I post this in the building/construction forum?

AtlanticWBConst.

Simple answer: Yes.

__________________
- Build Well -

Termite

There's no problem with attaching the wall to the underside of the furdown for the duct. Just build your furdown solidly enough to provide good lateral support for the top of the bath wall. As for the floating walls, build it the same way if you want to (it may be a local requirement).

raam

^^^ as stated above. The partition wall is just supporting itself.

epeterson777

Awesome, thanks for the help that will work out perfectly. I really didn't want to move that wall out. It would've ruined my billiards room. I do plan on beefing it up more than a typical soffit so I am not worried about the strength of it, I just wasn't sure if it was an acceptable practice. Thanks for the help I am sure I will be posting on here a lot in the upcoming months.

Termite

We're here to help!

bob22

What is the purpose of a floating wall and why required in CO?
How does it differ from a regular wall that has toe and top plates nailed to floor/ceiling?
TIA,
Bob

epeterson777

A floating wall is required in CO because the soil here is expansive. When it heats up it expands to the point where it can lift the floor in basements. You have a floor plate that gets shot into the floor then you have a gap (1.5" minimum in my town) then you have a bottom plate then the wall then the top plate which fastens to the ceiling joists. Between the bottom plate and the floor plate you need large nails that the wall can "float on." When you hang the dry wall you leave a gap that will be covered up by the trim.

Some places are worse than other here. We have a "higher end" mall that is in an area where the soil moves a lot and a lot of the store owners have sued the mall because the ground moves to the point where it can crumble walls. The sidewalks and roads can get pretty messed up too.

LadyRed

We are here in Co also & are having lots of fun with the floating walls that we are putting in to frame our basement.

The other thing that can happen with expansive soils if there isn't a floating wall, the movement in the cement slab will not only lift & damamge the walls in the basement but can lift the whole house off of the foundatation & then you have more issues.

ron0805

I just moved to Wyoming a few months back and now im going to finish my basement.I came from the east coast and i never heard of floating walls.Ive been told that here its 3" of a gap but i think thats a bit much,do u hav any idea how much of a gap it is in wyoming? Also will i hav to make the gap at the top for the walls that hav doors?

epeterson777

You'll have to check with your local building department. When I was pulling my permit they had a hand out that had the dimensions on it. You might not even need to have floating walls up in Wyoming. It all depends on the soil composition. I would just call and say that you are thinking about finishing your basement and you were wondering if floating calls were required. Another tip I would recommend is if you do pull a permit to finish the framing and other rough ins first. That way you can go at your own pace. If I didn't have my first inspection in the first 6 months then I needed to get an extension.

The gap where I live is supposed to be a min of 1.5" and a max of 3". I went with 3" but you'll need to get bigger trim, which costs more.

Daniel Holzman

I understand the need for floating walls, but just curious, how are foundations built in areas where the floating wall is required? Do you excavate below the poor soil, build a post tensioned slab, install piles, or some other technique?

epeterson777

I've kind of wondered about the workings of it myself. All that I can tell you is that my house has two steel I beams running perpendicular to the joists in the basement. Those beams have other beams holding them up that go into the concrete. So below the concrete I am not sure what it looks like. I haven't actually looked at a house being built here to see how they do it.