Scree Coat or Not to Prepare Walls for Liner Paper

[kdalman]

We just received our wall paper and have gotten different opinions from 2 different installers -- all highly recommended. I called the distributor, Lee Jofa, who suggested I contact the NGPP.

The paper is metalic and flocked. The house was built in 1932. The walls are plaster but we recently completed a construction project and so in the room where the paper will be hung, drywall is patched into the plaster. Also, the plaster looks like it has been repaired -- is has a more bumpy texture in some places. Except where in the location of the dry wall patch, the walls are painted with maybe an eggshell finish.

The question is this -- should we/can we apply a think coast of plaster on the walls to even them out before installing the recommended liner paper. One paper hanger believes this is the course we should take. However, another paper hanger with 40+ years experience has told us not to scree coat the wall before hanging the liner and then the paper -- he believes that the scree coat will cause the liner and paper to eventually pull away from the wall.

Because the 2 paper hangers have such opposite opinions -- I wanted to check with the NPGG to find out whether the concern about the scree coat of plaster approach (which seems most prudent to me) is truly a dangerous way to proceed.

Thank you for your advice on this.

[Lee Epstein]

The first thing you need to know is a metallic faced paper, either foil or mylar, will show any imperfection in the wall. It will even magnify it. So your walls need to be as smooth as possible. Skim coating is not always a great idea. But in your case I hesitate and say do it. Have the person who is going to prepare the walls apply a coat of Gardz to the wall. Then skim them with joint compound. After they have been skimmed he will need to sand them smooth. After that have him apply a coat of oil-based paint or primer. After that apply the Gardz again. Then your walls are ready to line. Use a 32 inch wide lining paper . This way less seams to open. Cavalier Liners carries lining paper in this width. Be sure to cross line the walls. (Hang it sideways.) Then wait at least overnight to hang the top goods. Use Roman's 880 Ultra-Clear Adhesive or a comparable wallpaper adhesive. I had to do the exact same thing to my own sister's kitchen. And there is nothing popping as of yet, 6 months later. Best of luck to you..

[HangingInThere]

... he believes that the scree coat will cause the liner and paper to eventually pull away from the wall.Did the hanger provide the logic for arriving at his conclusion??

[Boston Hangman]

We just received our wall paper and have gotten different opinions from 2 different installers -- all highly recommended. I called the distributor, Lee Jofa, who suggested I contact the NGPP.

The paper is metalic and flocked. The house was built in 1932. The walls are plaster but we recently completed a construction project and so in the room where the paper will be hung, drywall is patched into the plaster. Also, the plaster looks like it has been repaired -- is has a more bumpy texture in some places. Except where in the location of the dry wall patch, the walls are painted with maybe an eggshell finish.

The question is this -- should we/can we apply a think coast of plaster on the walls to even them out before installing the recommended liner paper. One paper hanger believes this is the course we should take. However, another paper hanger with 40+ years experience has told us not to scree coat the wall before hanging the liner and then the paper -- he believes that the scree coat will cause the liner and paper to eventually pull away from the wall.

Because the 2 paper hangers have such opposite opinions -- I wanted to check with the NPGG to find out whether the concern about the scree coat of plaster approach (which seems most prudent to me) is truly a dangerous way to proceed.

Thank you for your advice on this.

I agree with Lee that the walls will need to be as level and smooth as possible. I did an install with a "patent leather look" vinyl over some old plaster walls..of course I advised the designer and the homeowner that the walls were going to show all the imperfections and they both thought it would be acceptable and apparently it was.

However I am a little concerned about a scree coat . When a wall is levelled this way it is susceptible to falling away and I am sure most paperhangers and painters who have been in the trades for a while have seen their share of these failures, I have. I would assume your 40 + year paperhanger has seen this as well. I work with some very good plasterers up here in Mass who would normally go over with 3/8" plaster board then skimcoat rather than go right over the existing plaster. The problem here is you either remove the existing plaster , a very expensive and messy project or build upon your current walls and lose the depth of your trim work which detracts from the overal look of the room.

If it is just the "bumpiness" of the walls you may be able to do a light skim in the heaviest areas and use a bridging liner followed by a blankstock pulp liner to minimize the imperfections of the walls. I would use Gardz or Draw Tite to seal the bridging liner as well as any patching/skimming before installing the blankstock.

I do not see the need to prime with an oil primer over the scree coat if you go that route. I would prepare the walls with Gardz or DT then blankstock. I would also prefer to see a bonding type skim coat such as Dura bond or similiar hot mud coat rather than a traditional joint compound.

Good luck.

Mark

[HangingInThere]

I've seen old plaster walls conjoined with drywall, just as you have described, treated solely as a drywall application. I've not had to deal with all that many of them, but I've not seen any problems when they just went to taping cement to skim smooth. I actually did so in my own home whose walls are plaster. I removed a wainscot of oak beadboard, drywalled, and used taping cement to tie the two together. I then wallcovered the room with a fabric-backed vinyl that to this day has no issues.

It did take a bit of mudding... I found the plaster walls to be deceptively different. Even adjusting varying thicknesses of drywall board, on two walls the drywall was not quite as thick, on one the drywall protruded, and one broke even. A seasoned taper I know instructed me to put a straight-edge onto the plaster to be able to really see the illusion...nope, it wasn't anywhere near as flat as sheetrock!

That said, drywall mud is much easier to handle than plaster. Would it be possible to prime the hybrid wall, and then skim-coat, etc??

[Lee Epstein]

The reason I recommended using oil base is to harden everything up. Gardz I am afraid if used alone will still allow moisture from the adhesive to penetrate. I've seen skim coated walls fail like this. All the seams opened up, taking the compound with them. Making repairing difficult if not impossible. Like I've said in the past, I do not recommend hanging over skim coated walls. But resheetrocking can be costly and labor intensive. The method I stated before has been tried and has worked. It may be overkill but material bought from Lee Jofa is not cheap and you can view this like an insurance policy.

[HangingInThere]

I'm also for oil priming if it is available where you live. Although stinky, I prefer to use Kilz oil based primer whenever I want to ensure a substrate is sealed up for drywall work. It may be overkill...but I've never had a failure with this method and I'm just much more confident with an oil product's ability to withstand moisture laden drywall work.

If the job warrants it, I would Kilz the skimcoat (vacuuming sanding dust first) and Ultra Prime atop that for the install. I also prefer the standard premixed drywall muds....the new dust control for sure as an easily sandable top coat. IMHO ;)

[Boston Hangman]

The reason I recommended using oil base is to harden everything up. Gardz I am afraid if used alone will still allow moisture from the adhesive to penetrate. I've seen skim coated walls fail like this. All the seams opened up, taking the compound with them. Making repairing difficult if not impossible. Like I've said in the past, I do not recommend hanging over skim coated walls. But resheetrocking can be costly and labor intensive. The method I stated before has been tried and has worked. It may be overkill but material bought from Lee Jofa is not cheap and you can view this like an insurance policy.

Gardz and DT are sealers ,I am pretty certain you would not have a problem with moisture. I know that sometimes a second coat is used to ensure that the drywall or compound is thoroughly sealed, but that is not the norm , in my experience. They are both very hard upon drying and are better suited for wallcovering than most oil primers not to mention they dry faster and are an easier application and clean up. :thumbup:

Oil primer is sooo 70's ;) and Kilz ??really???

[HangingInThere]

Oil primer is sooo 70's ;) and Kilz ??really???I know...I know, but I've a perfect track record when skimming and I'll soon be 58...:o

[Lee Epstein]

It's O.K., my kids tell me I'm so 1970's also. :roflmao:

[Bill Archibald]

First, your terminology "scree" has me wondering what you mean.

"Screed" is a strip of plaster on walls that are being plastered to guide the thickness of the next coat (That's a brief and incomplete description)

So, please allow me to assume you are talking about skim coating the wall.

Secondly, if the plan is to apply a lime/gypsum finish coat of plaster, will a bonding agent be used to assure adhesion to the existing surfaces?

Thirdly, how thick will this skim coat be?

If the skim coat is applied properly, then I will beg to disagree with the old timer (I only have 37 years experience with paper, paint, and plaster) If he is talking about throwing some drywall mud on, smoothing it, then sanding it, and without proper preparation, OK, then I'll agree that process has a higher chance of failure.

A real plasterer would be better suited to answer your concerns about the possibility of coating the walls with a bonding agent and them applying a real coat of finish plaster, like Diamond Veneer finish plaster.

Plastering is an art that not many paperhangers, painters, or carpenters have mastered. I'd leave the question to the pros in that field.

[kdalman]

Thank you all for your comments, thoughts and recommendations. I have shared the different thoughts with our hanger. Still trying to figure out the best way to approach the project . . . keeping my fingers crossed. Just wish our designer, architect and contractor had raised the issues associated with this project (patching drywall into plaster vs. a plaster patch) . . . I will let you know how it goes. Thank you NGPP for hosting this bulletin board -- as am a homeowner with little knowledge/experience with the art of wall paper hanging and this resource has been great. Thank you again for your help on this. Kristina Dalman

[Chris Murphy]

You've gotten so much conflicting info I hate to add to this discussion, but I'd like to see you come away with a completed project: the paper's bought, and I doubt you could return it.

Plaster and joint compound are different animals: different materials and different chemistry. I won't even get into all the permutations of other materials in the other posts. Plaster and the "setting-type" compounds have no adhesive properties of their own; they need a bonding agent or physical 'key' (like wood lathe) to adhere. Joint compound (and do not, ever, get into "topping compounds" or other junk) does have adhesive properties, and will stick to plaster; it shrinks a lot, though, and can only be put on so thick, like less than 1/4" (or it cracks).

When stuff fails, it's either investigated to find the exact cause, or failing that, finger-pointing ensues and a lot of conjecture and superstition takes the place of good information. Fellas, it doesn't sound like you know why the failures occurred, and I'd consider them irrelevant for this case: you just saw the failure, not the steps previous. They've got a GC on this job, let him vouch for what his subs did. They most likely used joint compound, and that should be fine. Fine.

I'm not on site, but this is what I'd probably do: sand all the uneven wall surfaces, coat the whole thing with Gardz. Then I'd skim with spackle (not the light-weight) if it is small areas, joint compound (JC) for large ones. It may take a couple applications, but JC is easy to work with. If you've skimmed it 'tight' (i.e., not much excess applied) there won't be a lot of sanding needed. Coat again with Garz.

Cavalier's blankstock, of any weight (use whatever width your comfortable with; I like the heavy weight stuff) is a good choice. I don't bother cross-lining, as the chance of the finish paper seam falling right on a liner seam are pretty darn small, but I do keep it in mind on the focal wall.

[jphillips]

If you were on a tight budget, I'd skim with JC, but you mention designer, architech, liner, I'd have a plasterer skim it, around here they use plaster weld to make it bond, then a veneer coat of plaster.
On a tight budget?, I skim coat alot with Joint Compound, seal with gaurdz primer, then pigmented acrylic primer, never had problems; but I always tell homeowners, best way is plaster