Danger Signs of an Unstable Wall Surface

These nails were holding picture hooks to the wall. The hooks had an adhesive backing. When they were removed from the wall, chunks of latex paint stuck to them and pulled away from the wall, revealing a crumbly sub-surface. This is bad news for wallpaper that might be hung on top of this.

Other spots. What happens is, this is a 90 year old house. Over the years, many coats of paint and other surface treatments have been applied to the walls of this dining room. These coatings are not necessarily compatible with each other. Plus they may have been applied without the proper surface preparation. Oil based paint, then latex, then someone rolls on a gloss paint, the next guy follows with latex but neglects to de-gloss the previous layer so the new layer doesn’t really stick well.

Somewhere along the line, something got chalky. Here you see I have wiped crumbly chalky substance from inside the wall. This is why the latex paint is not adhering well and pulled away so easily. Nothing sticks to dust or grit or chalk.

Gardz is cool stuff. It’s a penetrating sealer that soaks in and actually binds crumbly materials together, drying into a hard, solid mass. The problem here is, it won’t penetrate the paint that is on top of the unstable layer, so we’re still dealing with a wall that has potential to come apart (delaminate).

Gardz applied. You can see how it has soaked into the porous areas, but is sitting on top of the latex paint.

The problem with an unstable wall and wallpaper, is that, as wallpaper sits on a wall and the paste dries, the paper shrinks just a tad, and this shrinking puts tension / torque on the wall beneath it. Sometimes this is actually powerful enough to pull the layers inside the wall apart, resulting in seams that split open.

These are not “loose seams,” but the paper actually taking layers of paint and dust along with it. Really can’t be repaired.

So best to find a way to prevent it from happening in the first place. More on that later.

Stay Away From Paper-Backed, Solid Vinyl Wallpapers

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Digital Image

Digital Image

Digital Image

Solid vinyl wallpapers are often marketed as “kitchen and bath” papers, because they are somewhat more washable than other types of wallpaper, and because splashed water will run right off the vinyl (plastic) surface.

However, I find just the opposite with these solid vinyl papers, particularly the pre-pasted, lower-priced ones.

The seams generally never look great to begin with. Then the porous paper backing tends to absorb moisture, such as humidity in a steamy bathroom. When the paper absorbs moisture, it expands, and when it expands, it has nowhere to go but to push away from the wall – causing a curled seam. Often the top vinyl layer even starts to delaminate from the paper backing.

This is not a “loose seam,” and it cannot be “reglued.”

Humidity is a factor, but so is improper wall prep. Usually, when there are curling seams like this, the previous installer neglected to prime the walls, and just hung wallpaper on top of the bare drywall.

In the two photos with paper curling away from the top of the baseboards and from the top of the granite countertops, it is not sticking because the surface beneath it is slick – overspray of gloss paint from the woodwork, caulk used around the top of the backsplash. Again, a primer would have prevented this.

I also like to run a bead of caulk around the top of the backsplash, to prevent splashed water from being wicked up under the cut edge of the wallpaper, which would cause curling.

I have blogged a number of times about curling seams due to crummy paper-backed, pre-pasted solid vinyl wallpapers. Choose some key words and do a Search here to read more.

Wallpaper Coming Loose – Bad News for the Homeowner

I was called to do some repairs today, where the wallpaper I had put up two or three years ago was coming loose at the seams. There was one seam a few feet away from the corner involved, and then also the edge of the wallpaper that fell in that corner.

I reglued the loose seam, and then moved to the corner strip. Before fixing something, I like to understand what went wrong to cause the problem. If you know the underlying cause, you have a better chance of fixing it, and you also have the knowledge to prevent it from happening in the future.

But I could not figure out why this paper was not sticking to the wall. After a little investigating, I discovered … that there was a layer of black powdery mold behind the wallpaper.

After more investigating (which involved pulling the entire strip off the wall), we discovered that there was some kind of water leak, probably from the roof or the exterior wall, that was allowing moisture into the wall. Moisture is going to cause mold / mildew, but with the vinyl wallpaper on top of the wall, which won’t allow air to pass through, the situation is exasperated.

Needless to say, I ceased with the regluing. And needless to say, the poor homeowners have a larger situation on their hands, to find the source of the leak and get it sealed up, and the wall repaired.

Bradbury & Bradbury Job – Loose Seams

For more on this story, read previous posts.

After working through a million types of paste (a slight exaggeration), and finally finding one that worked well with the paper and did not leave staining or “dark seams,” I was happy to have the job finished, and the homeowners reasonably satisfied.

But then a few weeks later came the call: “Julie, the seams are coming loose.”

When a job is well done, wallpaper stays on the wall, usually for years and years. One of the main factors that causes paper to come loose is humidity. (And I’m sure I’ll blog on that biggie some time down the road.) But this B&B was hung in a dining room, not a bathroom, so humidity was not an issue.
I was curious to see what had happened.

When I got to the house, I saw that the paper was, indeed, coming off the wall, with large areas of the seams coming loose, even up to 3″-5″ in spots.

Looking at the back of the paper, I didn’t see paste, which is what you would see if the paste had not held tight. Instead, the paper had a thick feel, and had a thin layer of the white primer adhering to it.

I’ve seen this once before – the primer had delaminated. Meaning, that the primer had come apart in layers, leaving one thin layer on the wall, and one thin layer on the paper, held by the paste.

I have only had this happen one time before, when friends talked me into using a water-based acrylic primer. So I was very surprised to see this happen with my standard oil-based KILZ.

Since the problem was only on the bottom section of the room, which was hung with the clay paste (the upper sections, which were hung with cellulose paste were fine), my surmization is that the failure was caused by an incompatibility between the primer and the clay paste.  Indeed, I have since learned that, due to the “green movement,” polymers in oil-based primers have changed, and pastes no longer stick to them, or at least not as well.  This experience seems to bear that out, as least with respect to clay-based paste.

But to deepen the mystery, the only walls with loose seams were the east and west walls. The north and south walls, and two narrow east and west walls, were perfectly adhered.

Weird!

Weird or not, mysterious or nor, the homeowners needed to have a proper looking room. So, after carefully measuring and plotting to be sure we had enough left-over paper, all the loose paper on the worst wall was torn off. There was just enough paper left to redo that wall, this time using cellulose-based Ecofix paste purchased from B&B, being careful to place the seams so they did not overlap where the old seams had been (to minimize stress on the wall, and minimize the chances of the seams pulling up – for a whole different reason, which just might be the topic of a future blog!) That took care of the west wall.

The east wall didn’t have as bad of loose seams (pardon the grammar), and we didn’t have any more paper anyway, so I worked the paste into the loose areas to readhere the paper to the wall.

This sounds like a quick fix, but is in itself tricky, because the moisture from the paste, as well as from my rags wiping the surface clean, can cause sections of the paper to swell and lift away from the wall, causing even more problems. The trick is to use enough paste to get the paper to stick, but not enough to allow moisture to wick to other areas of the paper.

This wall also had some shrinkage of the paper, which left very narrow strips of white showing at the seams. Once the paper was repasted, it stretched enough to mostly cover this. To be sure no white showed, though, I painted the wall just beneath each seam, a color that nearly matched the paper.

The replaced west wall looked good, the repaired east wall looked good enough (but I am not confident that the inner sections of the strips, which are still adhered with clay paste, will not eventually start to come away from the wall).

With the furniture placed back in the room, and people looking at the food on the dining room table instead of the walls, everything will be fine.

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Why the Painter’s Wallpaper Job Failed

In a previous post, I mentioned a home where I had done work in several rooms 22 years ago. But when it came time to do another room, I wasn’t available right away, so the homeowner hired their painter, who was working there at the time, and who assured them that he could do the job.

Well, it was not long at all, the homeowner told me, before his job started to fail. They lived with this for quite a while, but finally, with the date of a special birthday fast approaching, they called me to “reglue some seams” so the home would look nice for the party

Now, people tell me all the time that “All the seams are flapping open,” or “The wallpaper is falling off the walls.” Usually the real translation is that some of the seams are loose and need a little repasting. (Or have fallen victim to the curling common to solid vinyl papers, which I described in a previous post – and which I’ll probably rant about again, as it’s a pet peeve of mine.)

Anyway, when I got to the home, I was stunned to see how very bad the situation actually was. Virtually every single seam was loose, and most of those were loose on both the right and left edges of each strip of paper. The loose areas went horizontally from the edges of the paper from as little as an inch to as much as six inches, and ran vertically from five inches long to the entire length of the strip. Some corners were literally waving at me from the wall!

Whenever I encounter a situation like this, I like to figure out what went wrong, why the job failed. Because I think that if you know what went wrong, you can take steps to prevent it, and therefore keep a job from failing down the road.

In this case, after studying the wall, the adhesive, and the paper, and after talking with the homeowner, I think the problem was caused by FAILURE TO PROPERLY PREPARE THE SURFACE, and to be more specific, FAILURE TO USE A PRIMER.

In fact, the homeowner said that as the painter got his tools and started to put the paper on the painted wall, she said to him, “Our paperhanger Julie did the other rooms, and she smoothed the walls and painted on a primer. Shouldn’t you sand and prime, too?”

And he told her that neither procedure was necessary.

Well, we see where that led!

I don’t have an opinion about smoothing the wall, because I was unable to tell if there was texture behind the wallpaper or not. The paste had turned gritty and crumbly, so it was hard to tell if wall texture was also in the mix.

But I do know that the guy did not use a primer. I believe that this was the crux of the problem.

The original surface was paint. A good oil based primer (I use KILZ) would have sealed off that paint. Why do you want the paint sealed off? Well, wallpaper paste, like many glues and adhesives, reacts with some paints, and when it does – it causes crumbling and crackling. In fact, the adhesive called hyde glue is exactly what faux finishers use to create a “crackle finish.” Hyde glue + paint = cracking.

Moral of the story: ALWAYS USE A PRIMER.

Now, you’re probably curious as to how this turned out. Well, I got on my ladder and spent a couple hours slipping paste into the seams and then squeeging it back behind the loose paper. This is tricky in itself, because the wet paste tends to wick moisture into the surrounding dry wallpaper, which absorbs the moisture, swells, bubbles, and creates still more loose areas!

Long story short, I got all the seams to stay down, and everything will look nice for the special birthday party. I would be interested ot follow up on this project, to see how my paste holds up. Because if my theory about paste reacting with the underlying paint is what caused the problem, then, because both elements are still there, theoretically it could happen all over again.

Let’s sure hope not. The homeowners deserve to have a room that looks pretty, and to not have to worry about wallpaper flapping loose.

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