What's going on with these plaster walls?
July 19, 2014 8:50 PM   Subscribe

I was planning on repainting my daughters bedroom in our 1920 bungalow. All walls were covered with 2 layers of wallpaper and several layers of paint...so I decided to strip them before repainting. This is what I got.

So the wall seems like plaster on lath that is in reasonable shape...there are some hairline cracks and some holes which I think could be fixed. The glue washes off easily and under that the wall is white, smooth, and hard. Yay.
But, the entire top portion of the wall (like a strip that starts above the door/windowframes) has damage throughout. The top plaster portion (the one that is usually white and smooth) is a different color and...crumbly. The transition zone from the top part to the bottom is in worst shape. There's like a 5 inch strip in the transition zone where the top plaster/gypsum layer just crumbles down if you tap on it (thus a few holes along the rim that you can see in the picture - they appeared when I took down the wallpaper). A grey coat with some kind of fibre (horsehair) is below the gypsum...Not sure what would happen if I were to sand or scratch the whole top part of the room, and I don't want to do more damage than is already done.

This, to me, does not seem like water damage from the roof since it is completely regular - it goes around the whole room and the transition line is completely straight throughout. Also, the ceiling looks fine to me. What on earth is this? Was the top portion of the walls replaced with bad material and then crumbled? (Or, my husband's theory, was the bottom portion repaired and the top is just an old and very out of shape original part of the house?). The ugly pink wallpaper that was the oldest layer on the wall must have been from the 60s/70s the latest (possibly even older)...so that means, whatever happened to the plaster beneath it must have happened before that time.

Have you seen anything like this? Most importantly, can I fix this? Not adverse to bringing in a professional, but of course I'd prefer to do it myself if possible. We would also prefer to keep the plaster and not replace it with drywall. We are in Berkeley, if that is relevant.
posted by The Toad to Home & Garden (10 answers total) 4 users marked this as a favorite
I believe that the upper, rougher area used to be covered by some kind of trim, crown molding, or other decorative element. If you pulled away your baseboards, I bet the texture behind them would be similar to this upper area. This plaster is all unpainted.

To fix it you just need to skim coat - easy for pros but kind of tricky for beginners.

Good luck!
posted by littlewater at 9:16 PM on July 19, 2014 [1 favorite]

Yeah, I have a 1910 bungalow and I would bet money that there used to be crown molding. Either they ripped it out in order to wallpaper the room (ouch!!!), or perhaps it was already damaged and they used wallpaper to cover it up. I would patch it, or patch it and replace the molding.
posted by Violet Hour at 9:40 PM on July 19, 2014 [2 favorites]

That is pretty deep for crown moulding but a plate rail could have been up there and contributed to the horizontal strip of damage. I agree with littlewater you should skim coat it.
posted by saucysault at 9:46 PM on July 19, 2014 [1 favorite]

Here's a link that might explain a bit about the fibrous plaster you have.

The plaster at the top of your wall looks almost exactly like the raw plaster in my 1911 bungalow. In our case, we removed decades of wallpaper over painted-on wallpaper over more wallpaper to find the original, unpainted plaster. Ours wasn't crumbly like yours but there were a few spots here and there that were damaged.

I think that line is too low to mark crown molding, and too high for a plate rail unless I'm completely misunderstanding the scale of the room. What it could be is a picture rail. Or, where a picture rail was. Above the picture rail was possibly some decorative wallpaper, and below the rail may have been paint or different wallpaper. Perhaps two different wallpapers with different glues...

Incidentally, in that picture of my house I linked earlier you see a similar line. That line shows the shape of the original mantelpiece, which extended upwards on the wall from the top of the fireplace. By the time I moved in, that part of the mantel was gone. Only removing the wallpaper showed us where it had been. (And this year, 12 years later, I finally returned it to its original appearance.)

If you look at the top of my window you also see other lines that look like little rectangles on top of the window frame. Those indicate the location of wood that had been cut off the frames (which we could see when we climbed up to look).

So, basically, you have a ghost of the earlier appearance of the house. It's showing that the walls were divided with a possible picture rail or something dividing them. It's also possible that the lower part was wainscoting, but I think less likely. Fragility at that line is not too weird -- if there was any woodwork installed there, the plaster has had nails in it there, making it more fragile.
posted by litlnemo at 10:53 PM on July 19, 2014 [3 favorites]

Here are some images that show what might be similar to your walls:

Folks ripping wallpaper off a wall with a picture rail at about the same height as your line

Two different kinds of wallpaper with what looks like a wide border at the top (though I don't know for sure; I can't see the scale). It's also a 1920s bungalow.

Before -- and after in another 1920s house.
posted by litlnemo at 11:15 PM on July 19, 2014

Since you mentioned the age of the house (1920) and the approximate age of the oldest wall paper (60s/70s), and because it's your daughter's room, here's a reminder about proper lead-based paint clean up. If you don't know whether you've got lead or not, testing is easy. Then you'll know how serious to get about the clean-up process.
posted by klausman at 11:22 PM on July 19, 2014 [2 favorites]

Seconding that this was where a picture rail was removed. Here's a pic of how they look in my house. If you're redoing the room, they're a neat feature to add because you can use picture rail hooks to hang artwork without worrying about making holes in the walls.
Patching and skimcoating over the plaster is the way to repair the cracked/crumbling parts. I'm not a pro, but I've had good luck on minor lath & plaster repairs using drywall joint compound (the kind you mix yourself) and a window washing squeegee for the final surfacing and to blend the patched/skimmed area in with the original plaster.
posted by zombiedance at 11:27 PM on July 19, 2014 [3 favorites]

Yeah, this is completely normal for that era. The picture rails were probably removed at some point. If the top portion was unpainted and unwallpapered it could have suffered more degradation from humidity or other air quality issues.

Work your network and find a reasonable plasterer who can fix this for you. He'll (She'll) be able to do it in a fraction of the time and many times thequality that you could achieve, unless you're fully committed to doing your whole home by hand -- this is in fact one of those things you'll thank yourself for hiring a pro when you can look up and not see every flaw in your own work.
posted by dhartung at 12:11 AM on July 20, 2014 [1 favorite]

Just wanted to add that some plaster from that era might contain asbestos! I would have it tested before you start disturbing it. The presence of horse hair is a good sign (hair and asbestos tend to be mutually exclusive) but not definitive.
posted by The Hyacinth Girl at 3:25 AM on July 20, 2014 [2 favorites]

If you want to skim coat yourself, I have a neat trick: use a notched trowel. You cover the area you want with a notched trowel and let that coat dry. This establishes a uniform depth. Then you come back with a regular trowel and fill in the lows and you have a perfectly even layer.
posted by werkzeuger at 5:46 AM on July 20, 2014 [4 favorites]

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