PDA

View Full Version : "Veneer" Plaster: Did I blow it?



Hans Noeldner
07-14-2004, 11:00 PM
On my current job I decided to flatten some rather wavey wall surfaces in preparation for installing wide, stiff trim (5-1/2" x 3/4" oak). The walls had sound, well-attached drywall on them and they had been primed and painted with good quality latex.

I applied Plaster-Weld to some of the wall area -- where the low spots appeared to be. But after I got going with a 6' darby I ended up skimming almost the entire wall, including large portions without Plaster-Weld. I did roughen the paint by sanding it first, however.

I didn't use traditional plaster. I started the job using all-purpose premixed drywall compound but then switched to powdered lightweight setting compound. I finished with premixed topping. I applied in coats no thicker than 1/8" and total buildup is probably less than 5/16" in all but a few spots.

The drywall compound seemed to stick to the paint just as well as to the Plaster-Weld. Maybe even a bit better. In fact, in a few places where I re-sanded down through the Plaster-Weld surface, the Plaster-Weld seemed to peel off the paper with distressing ease.

Now here is my nightmare. Come winter, or after a few seasons, the joint compound I added over the paint and Plaster-Weld will start to pop off. I can imagine that water vapor, as it moves into and out of the drywall, will encounter the paint layer and Plaster-Weld beneath the mud and this cause the problem.

Am I nuts to worry about this? Right now the surface seems very sound and well-adhered.

Incidentally, if I faced this problem again, I would definitely just tear off the old drywall, properly shim and level the studs, and then put up new drywall. The approach I took was too much work!

Myron, I'm really glad I got your book; it has been very helpful to me. But it didn't cover this matter!

Myron Ferguson
07-19-2004, 09:19 PM
I think the walls will be fine. I have coated over numerous walls over the years. Sometimes large repairs where the compound is thick in places. As long as the surface under the skim coat is sound it will be fine. Just paint with a latex paint.