[gpsmith]

Hi all, I'm back again looking for your helpful advice.

I'm adding a door to be able to close off a 42" wide hallway from the rest of the house. It's not load-bearing, and from a construction point I'm feeling confident.

I'm planning to remove the existing drywall to tie in to the walls correctly, and I can tie into the ceiling easily enough. My question revolves around the floor. I have a 5/8" subfloor, and a 3/4" underlayment upon which lies carpeting.

As I see it, I have two options. I can cut out the underlayment plywood before framing the door (which probably calls for an oscillating saw I don't have yet), or can I simply cut out the carpeting and padding and set the side jambs on top of the underlayment.

I can see pros/cons to both approaches, but would like to know what you guys would do.

Thanks!

 

[joecaption]

No need to cut anything but the carpet and padding.
Going to have to add some carpet strip to hold in in place around the cuts.

 

[carpdad]

I don't see a problem with building on top of the carpet. Recarpeting can be done easily and you don't gain anything by cutting the carpet. Protect the carpet with rosin paper. Build on top and cut it out before the trim.

 

[jagans]

Why does he have to cut the carpet? This is an interior door with no threshold isnt it? Why cut the drywall? Just find a stud on the hinge side of the door and pack it out with studs (3 per side) so you can fit drywall and casing. On the wall opposite the stud on the hinge side, cut out the drywall 3.5 inches wide by 14.75" vertical at the top, middle and bottom. Leave the drywall between these cutouts. Work in three cats to span between the studs on the opposing wall, rotate into position and toe screw cats to studs. Patch drywall and pack out like opposite wall. You are making it harder than it has to be. Your RO needs to be 2 inches wider than your door, and 2 inches taller than your door. Buy a prehung door and pack out evenly as needed. You should be able to get a 2'8" in there.

Underlayment and subfloor are the same thing no? Why would you cut them at all?

 

[gpsmith]

I don't "have" to cut the carpet, but I'm trying to think long term. The carpet will be replaced in the next year or so, and I don't want to deal with cutting the old carpet out from under the jambs at that point.

As for cutting out the underlayment, I was looking at the construction of the overall house for nominal. The existing interior walls are built on the 5/8 subfloor, and the 3/4" underlayment was added later (with a bit of a gap between the edge and the 2x4 to accommodate the thickness of the drywall). I'm presuming that's to make floor repairs easier. You wouldn't have to cut out the plywood when it passes under a wall (basically, the same reasoning I'm using on the carpet issue).

Of course, this house has already proven itself a weird and sub-par construction in many ways, so I wouldn't be surprised if that reasoning is flawed...

Thanks!

 

[joecaption]

There is no such thing as 3/4" underlayment.
Just a few reason to cut out the carpet.
It will appear crushed in that area.
How are you going to remove the carpet strip againt the wall without removing the carpet?
Not going to get a 100% solid, never going to move connection to the subfloor.

That's something I'd expect to see in a mobil home.