“Veneer” Plaster: Did I blow it?
If you know about this issue, please be honest with me; don’t worry about being nice.
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 joint 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 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 that I added, and this will 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!
Replies
Woody,
You are gonna paint the wall again right? Paint it and forget about it... it should hold up just fine.
Davo
Thanks for your input Davo. Yes the wall will be painted again.
Yes you did.
Next time don't use plaster weld.The old and dry paint gets loose by the plaster weld. And don't use premix compound as the first coat, and setting compound as the second coat.
The premix joint compount needs more time to cure and by applying the setting compound in top of it,( that by the way sets faster )(Setting) you don't allow it to cure right and it will push or at list not allow the bonding to take place.
Next time use the setting compount first and before even sets you can use another coat of setting or even a premix joint compound.
YCF Dino
Thanks for your input. It did seem like the Plaster-Weld made the paint brittle.
Are you advising I REDO this job or just that I do it differently NEXT time? Any personal experience with compound eventually popping off under similar circumstances? I suppose I COULD rip off the old drywall (GULP!), properly flatten the rough walls, and put up new drywall. However, I can think of someone who would probably kill me if I did this.
Thing is I will be installing some beautiful (expensive) custom-milled oak trim and it would about kill me to see chunks of compound popping off once the trim is up.
Some times you get lucky. It all depends how good the first coat was dry. In your case you have to worry about the plaster weld too.
I would laminate the walls with 1/4'' drywall and get done.
Let say that you prepare the walls for it. Use special drywall screws made just for that. You don't even have to find the beams. But use some liquid nail at the seams.(just to make sure)
To make the job go fast use fiberglass tape and the same setting compound that you may have some left.
Before the compound sets you can smooth it with a sponge and you can even apply the joint compound in top of it and get done the same day.
In plastering timing is everything.
Good luck.
YCF Dino
Edited 7/20/2004 1:32 am ET by YCFriend
Hi Woody.
YC makes some valid points...setting compound first, and then later use the premix on top.
I know nothing about plaster weld...never used the product. I have used both pre mixed joint compound ( slightly thinned down with water and or paint) as well as the fast setting for skim coating low spots. I've also used the pre mixed for more decorative finishing...all put on top of previously painted drywall....never had any compound come loose and pop off. I've heard of this happening to others, but never to me.
Painting the wall should help seal your skim coat and act as a moisture barrier...the fact that total thickness of skim coating is less than 5/16 of an inch, I would not think this should pose a problem. Now that coating is dry, run your hand over it lightly....does it feel loose? If so, there's your answer...if not, I'd say leave it alone.
It sounds to me like you are talking about a large wall area...right? If so, I would leave it alone if the wall felt tight. Why look for more work if you don't have to.
Just my 2 cents...but I'm not a plasterer, Iam a carpenter by trade. I've done a fair amount of drywall and mud work, but am no expert.
Davo