I was doing some electrical work at my in-laws this weekend and had to
relocate an electrical box. Unfortunately, they have plaster and lath wall
construction that quickly crumbled away as I was cutting the hole (it had
multiple cracks before I even started).

To get things fixed up as quickly as I could, I mounted the electrical box
and repaired the hole with the only supplies I had available at the time,
an old piece of 1/2" plywood. The switch box has a nice sturdy mounting and
it holds the wall together nicely.

Of course, the piece of plywood and the crumbled plaster edges don't look
all that great, so I'd like to patch it up a little to make it blend a
little better. The rest of the wall is in pretty rough shape already, and
we're planning on remodeling that room in a few years anyway. It doesn't
have to be top quality, but I don't want the patch to crumble away in a few
weeks either...

So, I'm curious if I can apply joint compound directly over the plywood
patch? I would use fiberglass mesh tape to control cracking, but will the
compound stick to the plywood? The plywood is very dry and has a rough
texture.

The overall patch is about 6" wide x 9" high.

Thanks,

Anthony

HerHusband wrote:
....
So, I'm curious if I can apply joint compound directly over the plywood
patch? I would use fiberglass mesh tape to control cracking, but will the
compound stick to the plywood? The plywood is very dry and has a rough
texture.

The overall patch is about 6" wide x 9" high.

It will do fine. You could always staple a small chunk of screen or
similar mesh to provide a little more "teeth" but more than likely for
the purpose of a "temporary" patch no larger than that you could get by
with just a skim coat then a finish coat (or two).

So, I'm curious if I can apply joint compound directly over the
plywood patch? I would use fiberglass mesh tape to control cracking,
but will the compound stick to the plywood? The plywood is very dry
and has a rough texture.
The overall patch is about 6" wide x 9" high.

It will do fine. You could always staple a small chunk of screen or
similar mesh to provide a little more "teeth" but more than likely for
the purpose of a "temporary" patch no larger than that you could get
by with just a skim coat then a finish coat (or two).

I know it's practically impossible to remove joint compound I've dropped on
a plywood subfloor! So I figured it would work fine. I just wanted to
see what experience others have had.

In any case, I just want to pretty it up a little. The whole house could
use a complete gut and rebuild, but we can only do a little at a time.

Thanks for the feedback!

Anthony

HerHusband wrote:
I was doing some electrical work at my in-laws this weekend and had to
relocate an electrical box. Unfortunately, they have plaster and lath wall
construction that quickly crumbled away as I was cutting the hole (it had
multiple cracks before I even started).

To get things fixed up as quickly as I could, I mounted the electrical box
and repaired the hole with the only supplies I had available at the time,
an old piece of 1/2" plywood. The switch box has a nice sturdy mounting and
it holds the wall together nicely.

Of course, the piece of plywood and the crumbled plaster edges don't look
all that great, so I'd like to patch it up a little to make it blend a
little better. The rest of the wall is in pretty rough shape already, and
we're planning on remodeling that room in a few years anyway. It doesn't
have to be top quality, but I don't want the patch to crumble away in a few
weeks either...

So, I'm curious if I can apply joint compound directly over the plywood
patch? I would use fiberglass mesh tape to control cracking, but will the
compound stick to the plywood? The plywood is very dry and has a rough
texture.

The overall patch is about 6" wide x 9" high.

Thanks,

Anthony

Hell yes..... believe me...joint compund will stick to anything that
gets in its way... ~:

HerHusband wrote:
So, I'm curious if I can apply joint compound directly over the
plywood patch? I would use fiberglass mesh tape to control cracking,
but will the compound stick to the plywood? The plywood is very dry
and has a rough texture.
The overall patch is about 6" wide x 9" high.

It will do fine. You could always staple a small chunk of screen or
similar mesh to provide a little more "teeth" but more than likely for
the purpose of a "temporary" patch no larger than that you could get
by with just a skim coat then a finish coat (or two).

I know it's practically impossible to remove joint compound I've dropped on
a plywood subfloor! So I figured it would work fine. I just wanted to
see what experience others have had.

Actually, if the plywood patch is behind the plaster so you have the
full thickness to build up, you'll probably get better results if you
have some wallboard around in filling the bulk of the hole with it and
then finish it like taping a joint. A full thickness a plaster wall w/
mud is likely going to crack. If the ply is at or very near the
surface, as I was originally thinking, no sweat.

If the ply is at or very near the surface,
as I was originally thinking, no sweat.

Yep, the plywood patch is screwed over the existing lath, leaving the
surface of the ply less than an 1/8" lower than the surrounding plaster.

Normally I would patch in with sheetrock, but when you're in a bind, you
use whatever is available...

Sounds like the joint compound should work well. Thanks!

Anthony