Replacing rotted sill plate in non-load bearing closet wall

[tekmonkey]

I have a basement closet adjacent to my water heater/utility closet which has a rotted out sill plate.

http://imgur.com/a/XPqak

As you can see in the photos, it's mostly the sill plate on the back wall of the closet (facing the water heater) which is damaged; the left and right walls of the closet are less damaged, though there is certainly some rot and there was some mold behind the baseboards.

The wall is not load bearing. It's lower than the rest of the ceiling. No joists sit across it. In fact, the left wall and rear wall both exist purely for the construction of the closet. The right wall is shared with the hallway, so it goes all the way up to the floor joists in the ceiling above (though it shouldn't be bearing much load as there's a big steel beam 8 ft away running across the length of the house.

The sill plate sits on my concrete basement floor. How can I replace it the easiest? I assume the board has been attached to the concrete, but can I cut it out with a reciprocating saw, then knock a new plate in beneath the studs? Since the rear wall is not supporting any weight, can I just cut the old board out, shove a temporary block under the center stud, then gently knock a new plate in?

 

[nealtw]

Yes you could do that, but I would do a little more.
I would remove the drywall up 12 to 18 inches. Cut the studs above the rot, replace the plate and put short blocks along side the old studs to extend them down to the plate.
Any rot that cannot be removed should be painted with a copper based treatment. The sill plate should be protected from the concrete with sill gasket or 6 mill poly sheeting.
Measure things like plates before you remove them and make sure the floor is marked so you get everything back in the right place.
You can do this in peices if you are afraid of taking it all out at one time.
In case that one wall is bearing, removing one or 2 studs like this for a short time will be alright, but after scabbing a block on the side just cut a block to fit under the old stud to add any needed support.
And yes I am saying, fix all three walls or you will be looking forward to be doing it later.
There will be mold on the back of that drywall, keep cutting until you have cleared it out.

 

[oldognewtrick]

Have you fixed the source of the water leak?

 

[tekmonkey]

Have you fixed the source of the water leak?

To be honest, not sure... I noticed the rot and mold issue because I had a pipe leaking above this spot. It's possible the leak has been happening for a long time, but went unnoticed and most of the water was absorbed by the wood. However, just recently the leak became noticeable and I replaced the leaky pipe.

I don't think it's coming from a crack in the concrete slab, as the sill plates on adjacent walls are fine (though I've noticed some other baseboards in other parts of the basement look though they could be rotting--might just be something minor from the humidity).

It is adjacent to the water heater, though it does not seem to be leaking.

Seems possible it might also be from a problem in the past, prior to when I owned the house. I never paid much close attention to this wall, and we have had other water seepage issues on the exterior walls.

 

[nealtw]

It could be as simple as wood sitting directly on concrete, there is moisture that will wick up from below.

 

[tekmonkey]

Yes you could do that, but I would do a little more.
I would remove the drywall up 12 to 18 inches. Cut the studs above the rot, replace the plate and put short blocks along side the old studs to extend them down to the plate.
Any rot that cannot be removed should be painted with a copper based treatment. The sill plate should be protected from the concrete with sill gasket or 6 mill poly sheeting.
Measure things like plates before you remove them and make sure the floor is marked so you get everything back in the right place.
You can do this in peices if you are afraid of taking it all out at one time.
In case that one wall is bearing, removing one or 2 studs like this for a short time will be alright, but after scabbing a block on the side just cut a block to fit under the old stud to add any needed support.
And yes I am saying, fix all three walls or you will be looking forward to be doing it later.
There will be mold on the back of that drywall, keep cutting until you have cleared it out.

Thanks, I was intending to open up the drywall a bit higher to replace.

When cutting the bottom of the stud, I'm not clear how to replace. Would I cut one piece to wedge beneath the cut (comparable to the piece I cut out), then two additional pieces fastened to both sides for support?

When replacing the sill plates, do I need to reattach them to the concrete floor with something like a ramset? Or will I likely be fine without doing that given these are small, standalone closet walls?

 

[tekmonkey]

It could be as simple as wood sitting directly on concrete, there is moisture that will wick up from below.

Agreed. Just odd as I've got a lot of other studs in the basement sitting directly on concrete which are not rotted (or perhaps only minimally and not very visibly). The back piece I showed in the photos is extremely rotted.

 

[nealtw]

Thanks, I was intending to open up the drywall a bit higher to replace.

When cutting the bottom of the stud, I'm not clear how to replace. Would I cut one piece to wedge beneath the cut (comparable to the piece I cut out), then two additional pieces fastened to both sides for support?

When replacing the sill plates, do I need to reattach them to the concrete floor with something like a ramset? Or will I likely be fine without doing that given these are small, standalone closet walls?

If you overlap the old stud with a block by about 12 inches and screw them together, non bearing wall is fine although you could replace the missing peice if you want and you have to replace that peice in the corners. If one wall might be bearing, for sure fit the block under the old stud.
A couple 2 " concrete nails will work fine, they only have to stab the concrete a little, just a poke will stop things from moving.

 

[nealtw]

Agreed. Just odd as I've got a lot of other studs in the basement sitting directly on concrete which are not rotted (or perhaps only minimally and not very visibly). The back piece I showed in the photos is extremely rotted.

Could be accelerated by the leak, once started just moisture in the basement will feed rot and mold.
Check your landscaping, make sure it slopes away from the house, devert downspout water away from house.
If you have rot around the perimeter wall, you may have a waterproof and drainage problem.
That's the kind of thing you want to find before you finish that mancave.

 

[joecaption]

No way would I be just removing only 12" of drywall!
Need to be removing 24" for several reasons.
That would give you enough room to see how bad the rot is.
Give you enough room to attach the needed minimum 24" long splice.
Far more likely there's some water issues coming in from the outside caused from foundation never being waterproofed and no drain tiles before back filling, no gutters, mulch or flower beds forming ponds, not enough slope in grade.
Before those walls went in there should have been 2" foam attached to the foundation.
Bottom plate should have been pressure treated.