Existing Floor, New Bearing Wall
Existing Floor, New Bearing Wall
(OP)
The wood-framed bearing wall in a walkout basement is inset from the ends of the main-level floor joists which creates a 15" cantilever beyond the basement wall. As part of a basement remodel, I'm looking to move that wall out so that it's stacked beneath the main-level wall framing. Does anyone have any advice for making sure that the new wall is built so that the supported floor is level (initial shimming?) and doesn't have differential settlement relative the the existing structure over time? Thanks in advance!
RE: Existing Floor, New Bearing Wall
RE: Existing Floor, New Bearing Wall
A few important things, though. If you have pressure treated lumber, spec it as KDAT (kiln dried after treatment) or force the contractor to dry it out before they use it. That stuff can show up sopping wet and shrinks as it dries. Not an issue if the whole house is being built at once and it dries evenly, but if they line everything up real nice with the existing while it's wet, you could end up dropping a bit. Use only synthetic shims like HDPE or other suitable plastics.
RE: Existing Floor, New Bearing Wall
Now, it's only 15" so not a great mile by any stretch. But still something will occur.
RE: Existing Floor, New Bearing Wall
Pham - Thanks for the comments, I appreciate it.
Enable - The existing wall will be removed, so I'm not sure why it would matter that the deflection at that point will change? The span would just increase by 15" (which would then match the span of the joists on the other half of the house - the side that isn't a walkout).
RE: Existing Floor, New Bearing Wall
RE: Existing Floor, New Bearing Wall
And as for Enable's comment, you are increasing the span of those joists, therefore you will see increased deflection in those joists potentially causing damage to existing finishes in the area. It doesn't matter that their new span will match the span of other joists in the area, the modifications you are proposing change the loading/support conditions and the structure will react accordingly. Draw the deflected shape of the currently loaded joists, then draw the new deflected shape. It should become quite clear at that point.
RE: Existing Floor, New Bearing Wall