Your client gets the drywall’s paper wet when he removes wallpaper, causing the paper facing to come loose from the drywall in some areas. When you go to finish the wall, the ripple only spreads, even after you’ve applied the mud and cut out the bad area. Is the board no good? Do you have to replace it, or can you make it work? How do you make it work?
The most cost-effective method we found to achieve the desired finish is to hang another layer of gypsum board over the damaged board. 1/4″ often works but 1/2″ may be necessary if the damage is severe. Also, electrical boxes, window trim and other in-wall items must be reviewed to determine if this is a viable solution for a particular project.- John Hall, Specon Systems, Inc., Pelham, AL
Spray primer over the wall. Then sand it. Any skimming required will not cause “blistering” since you have a new, sealed surface to work with. You then sand the wall to get the rough spots out, since painting the surface will cause some areas to be burred. Our service division just finished a house with this application, and it worked out great.-Tom Boscamp, Palo Verde Drywall Inc., Phoenix
If the face paper has delaminated from the gypsum core, the wallboard needs to be replaced.
-Bill Batting, Emerald Coast Building Materials, Gulf Breeze, FL
Couple of ways to fix problem: First is to laminate a new layer of 1/4″ drywall over old board. Or, you can paint Kilz over the damaged areas and then two skim coats of mud, then sand.-Anonymous
I have taken fast set and coated over the areas. It needs to be heavily coated. It seems to work well for me. But MAB paints sells a paint that keeps it from bubbling. I have not used it as much, but you can paint right over wallpaper with this paint as a primer.-Benny
Peel the paper on that particular sheet back as far as you can and apply mud to the face of the rock left on the wall and reapply the paper, trowelling it in. Let it dry, then continue the patch. If the rock is a fairly new installation-less than five years-this should work. If it is older it will probably be less expensive to the consumer to go ahead and replace the isolated sheet. If it is extensive it will be even more cost effective to laminate a layer of 1/4″ or 3/8″ directly to the face of the existing. The labor to skim along with the longevity of the project (skimming) will be an inconvenience to the consumer, and they will gladly pay the additional money to have their environment back sooner.-Tommy
Remove as much loose paper as possible. In order to bind the surface, coat the damaged wallboard with a high quality primer such as Kilz or Bullseye, allow to dry, then apply two coats of fast-set drywall compound with drying time between coats, sand and finish. Or, use a plaster bonding agent in lieu of primer, then coat with Imperial Basecoat and Keene’s Cement, sandfloat finish or trowelled lime and gauging plaster. Incidentally, we learned this the hard way on a very high-end residential remodel. It is very embarrassing to have this happen. For us, it was the painter that detected the loose materials.-Anonymous
Clearly, the drywall will not take the moisture. Do not even attempt to save. Demo and replace or screw 1/4 board over it if you have the space. Hard long experience talking here.-Bud Schaerer,
Schaerer Contracting Co. Inc., Chattanooga, TN
It may take three skim coats of compound. (If easy, sand mud is used on the bad areas first. It would take less compound and most likely two coats in lieu of three coats). The drywall would not have to be replaced.-Walter Humphreys, Finishes Inc., Sykesville, MD
The easiest cure for bad gypboard is new gypboard. Cut out the affected area and install new. Tape it up and be finished with it. You’ll end up ahead time-wise, money-wise and quality-wise.-Kevin E. Respecki, BEK, Inc., Aiea, HI
You might save the Sheetrock. First cut out all the paper on the bubble spots. Then apply an oil-based sealer on the entire wall, allow to dry, then reskim. This technique has worked well for us.-David McCauley, McCauley & Sons Drywall, Inc., Louisville, KY
As long as the wallboard is still in good shape, you should still be able to make it work. First be very certain that all problem areas are repaired and the wallboard is structurally sound. Then use an oil-based drywall sealer/primer to seal the wall. When you roll on the sealer, you should be able to see if there will be any more issues with the drywall bubbling. If you are re-installing new wallpaper it will serve a dual purpose, acting both as a wall decoration and as the same type of bond the wallboard paper did.-Craig Favors, Owner, Inside Expressions, Dallas, TX
