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Thread: Ask My Old House-Plaster Walls
09-25-2009, 02:16 PM #1
Ask My Old House-Plaster Walls
Bought a 1906 special. The plaster walls were never painted, just wallpapered. All paper has been removed. Besides the repairs, will I really be able to get the walls looking great with paint?
I am planning to have them skim coated with veneer, but would mind saving the cash if I can geta good paint job.
Any experience? Advice?Battle lines being drawn, nobody’s right if everybody’s wrong, old people speaking their minds, getting so much resistance from behind.
09-25-2009, 02:21 PM #2
I have mostly plaster walls and have been working recently on fixing a lot of them (cracks, soft spots, etc...) and I have to say it is a pain in the ass...but comes out nice once you figure out how to do it.
Anyway back to your problem. Feel the wall. If the plaster is smooth and even (all wall paper glue should be removed of course) then just prime and paint. Otherwise you will have to either touch up or do a skim coat.
If you do just prime and paint, buy a good quality primer. A lot of people say Kilz or Zinsser or etc.. is the best, just buy a name brand...not a generic crap primer.
09-25-2009, 02:21 PM #3
Well....what sort of condition are they in now? They probably need at least priming but I don't see the need for a skim coat unless the surface is somehow unacceptable.
09-25-2009, 02:22 PM #4
Forgot to mention, you can sand the plaster pretty smooth so unless there is an underlying or major issue, your good to go with the primer/paint.
09-25-2009, 02:49 PM #5with stoopid
- Join Date
- Nov 2008
- everyday sunshine
I'm a contractor in NYC, and I come across a lot of old plaster walls in varying conditions.
My rule of thumb with plaster walls is that unless it is falling off by itself don't remove it.
fix any cracks by widening them out in a V shape and filling them in with straight plaster of paris, then skim the surface of the repair with joint compund.
use wallpaper paste remover to get rid of the funky surface texture then sand smooth with a random orbital sander and 220 grit sand paper. Do yourself a favor while you're sanding and remove the dust collector bag and tape the exhaust to the hose of your wet/dry vac. (make sure there's a clean filter in the vacuum)
Some older plasters can be super hard and not very porous. To gaurantee a good prime coat use the zinser brand shellac based primer. it'll get you pretty high if you're not wearing a respirator, but it bonds to anything and will help smooth out any last surface defects.
if you have bigger repairs there are easy ways to take care of those as well.
compared to a modern sheetrock wall, an old plaster wall is amazingly solid feeling and a much, much flatter.
09-25-2009, 04:01 PM #6
Wow, something I actually know a little about, having a 1905 house, and having repaired walls in every room.
In short, most work was done by the husband, Paul, of a workmate to my MIL. He is a professional plasterer, and knows his stuff. Basically, if the wall was sound, but had significant spider cracking, and the occasional soft spot, he would repair.
All soft spots were carefully cut back to the wood lathe, taking care to only cut out the bad and leave the still sound, and properly keyed surrounding material. The bare plaster edges and wood lathe were painted with a product called Plaster Weld, which seals and keeps the old material/lathe from sucking the water from the plaster repair material before it has a chance to properly cure. Just like concrete, the slower you can make the cure, the stronger the final product.
If the spot was large, he supplemented the old wood lathe with modern expanded metal lathe, screwed to the old wood with drywall screws. Rough fill, to within 1/16" of the final surface, was done with Structo-lite, a brown coat plaster with perlite. Depending on the location, he finished with a white coat plaster, or Durabond 45. The latter is a setting type joint compound.
Finally, he went over the whole wall with a Glidden product called Glid-Wall. Basically, this is a fine, fiberglass scrim fabric. You can order it through your local, professional ICI Coatings store and it comes in large rolls (something like 3'x900'). In the original Glidden specification, it was to be put on with a special, primer, which I imagine would work. My plasterer put it on with a wet coat of general purpose drywall mud. He would add and extra 16-32 ounces of water to your normal general purpose compound, trowel on a thin coat, lay a piece of the Glid-Wall in the wet compound, then press/work it into the compound with his trowel. Properly done, you could see the joint compound come up through the mat, without completely saturating it.
After drying overnight, he would skim on another tight coat of general purpose compound, and let that dry. Then, depending, he would skim on another 1-2 coats of topping compound. Only use the topping for the final thin layers, as it is softer than the general purpose. The idea is for the topping to fill in all of the minor imperfections.
The last step was lightly sanding the whole wall with a 3M sanding sponge. He did such a fine job of putting on compound, that this last step was more of a light dusting/buffing. I always had to help at this point, and SOP was to hold a task light in the left hand, with a 300W bulb, angled oblique to the surface to highlight any imperfections, and sand simultaneously with the right. Of course, feel free to reverse if you are a southpaw.
It all sounds a little tedious, and I suppose it is, but the final result is excellent, and I haven't had to go over anything. Some of the repairs were done over 10 years ago, and are still perfect. Once you get in the groove, its not too bad, but I couldn't imagine performing the work without seeing Paul perform it first.
If you decide to jump in, the one key piece of wisdom is several, tight, thin coats are actually faster than fewer thick ones. Paul did very little final sanding, and between coats, just knocked off any slight ridge lines with a flexible drywall knife. A thicker coat would have had more and higher ridges, and may have required sanding between coats. Too thick with compound, and its going to dry unevenly and crack.
09-25-2009, 04:55 PM #7
09-25-2009, 05:51 PM #8
What Staggerwing said. We also have a roughly 100 year old house, with plaster issues. We used an absolutely amazing plaster here in Seattle to replaster one room and repair the plaster in two others. He used the same process Staggerwing describes. I know it well, since I was his "hoddie," and mixed many five gallon buckets of plaster to save on labor and speed the process.
I would consider having your plasterer pigment the finish coat and try not painting at all. We absolutely loved the look and feel of the unpainted plaster, but learned partway in that we could have tried pigmented plaster. If you don't like it you can always paint over the top. Remember it will take quite a while for the plaster to cure before you can paint it.
09-25-2009, 09:43 PM #9
Staggerwing- very good job describing process.
Here are some other helpful hints. Never seen plaster weld, but if you go in the concrete department of any hardware store they should have whats called 'concrete glue', this is same stuff and might be cheaper here. Soft spots(areas that have lost their keys) can be dealt with in other ways than having to cut them out. One involves drilling holes and injecting glue between wood lathe and plaster. Then screwing down with drywall screws in 'stucco' type washers. After glue has set, remove screw and washer and skim coat. Other way is to use 'plaster washers"(metal perforated washers) with drywall scews. Then skim coat.
Any time you fill something deep, use a setting type joint compound, it won't shrink.
Always remove all glue before beginning repairs and sand to.
Never used the glid-wall but have used stucco mat. Then glid-wall I imagine is finer fabric so it would probably work better.
Unless you have staining or the like I wouldn't use the shellac, you'll get better adhesion with a 100% acrylic primer (ICI makes a great one called Hi-Hide wall primer). If you do go shellac, plenty of ventilation and turn of pilots.
Also check into 'DIFS', Decorative Interior Finshing Systems. It will give you the look of old world venetian plaster. Pretty cool stuff.
Anyway, whatever you decide, good luck.
09-25-2009, 10:53 PM #10
This is the stuff you want, similar to concrete bonding agents.
09-26-2009, 12:38 AM #11
09-26-2009, 08:51 AM #12
Yes, forgot about the plaster repair washers. They can work, but see to be more of an item for the DIYer and hard core preservationist (want to remove as little historical material as possible). We tried those is a couple of rooms, but my plaster guy could pull the soft spots out, and repair properly just about as quick, and it was a better repair.
If you use them, be very careful and do the final set by hand. Out of the box, they are slightly convex, and when properly set, are flat to slightly concave. With a coarse threaded drywall screw and a driver, its not too hard to pull them right through the surface of a rotten section of plaster.
Yep, that is the product that I referred to. Doesn't seem much different than latex concrete additive, but, if going through all this trouble, you might as well get the product with a proven record for the job at hand. The pink of the PlasterWeld helps you see where you have applied it.
The Glid-wall to which I refer, is commonly known as a "wall liner." You can Google that term for more options. In the old days, they used to use canvas. I know there is at least one other company selling something similar to the Glid-wall product, but I don't know the details.
09-26-2009, 10:10 AM #13
Our plasterer uses a related product to Glid-wall for lining the walls, a self-adhesive yellow fiberglass mesh similar to that type of drywall tape. He calls it "Yellow Jacket," and used on areas which had been patched or had hairline cracks, including all the ceilings. He never used repair washers. Like Staggerwing's plasterer, he favors taking out anything that sounds out as failed and repairing with Structo and a finish coat.
After working with our plasterer for about a week, on and off, I will say that it is not very forgiving for amateurs. He thinks it takes about three or four months of trowel time to get to the journeyman level, if and only if your little visual-spatial brain can really handle the concept of FLAT. Which includes working from stilts on the ceilings. That awesome, smooth-as-glass finish you get from a master plasterer ain't easy to duplicate.
09-26-2009, 11:13 AM #14Registered User
- Join Date
- Mar 2008
- northern BC
well you got to repair any cracks or holes but then you can do a paint treatment that hides all sins
For about 35$ We got this paint roller& tray set that was split down the middle,the paint tray also has the corresponding split ,you fill the 2 trays with differnt colors ,in my case it was medium green and yellow the darker color will be the predominant color with the lighter highlight ... the effect was like a green cloud and it looked awesome
To apply you just roll like you would for any normal paint roller BUT because of the 2 colors and the mottled cloud effect you will NOT see any imperfections in the surface SO you are covering easily in one coat
there are various rollers and treatment ideas at paint stores ... I would definatley do it again
Last edited by XXX-er; 09-26-2009 at 11:28 AM.
09-26-2009, 11:19 AM #15with stoopid
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- Nov 2008
- everyday sunshine
As a pro here, I'll say...
You guys are all right on with your process, but if this guys walls are in decent shape you're just gonna scare him away!!
Most often it just takes a few patches and crack fixes to get a plaster wall right again, especially if there isn't years of paint layers giving you a really deep "orange peel" texture
we all know skim coating can get very pricey very fast.