Posts Tagged ‘delaminating’

Tape Test for Unstable Walls

September 21, 2022

There can be reasons for unstable walls, mostly cheap or poor quality paint, dust, someone applied paint over dust, improper prep, incompatible layers inside the wall built up over years (oil based paint, latex paint, dust, gloss paint, joint compound, etc.).

These can cause problems with wallpaper, mostly with the layers delaminating (coming apart), which causes the wallpaper seams to come away from the wall. Sometimes sheets of wallpaper simply fall off the wall.

This isn’t so much a problem with paint, because it just sits on the surface. But wallpaper shrinks when the paste dries, or expands and contracts with humidity, and can put tension on the seams

Before wallpaper goes up, one way to test for such unstable surfaces is the tape test . Use a razor blade to cut an “X” into the wall, scoring through the paint and maybe into a few layers beneath. Place a strip of blue painters tape over the cut. Pull the tape off the wall.

If paint comes away from the wall along with the tape, or if layers inside the wall come apart, you know you have to do a lot of specialized prep to stabilize the wall before hanging / installing the wallpaper.

This example is an interesting twist. The homeowner used a piece of tape to hold up a wallpaper sample. Then used an ink pen to write notes on it. When removed, the tape took the paint off – in the shape of the writing!

William Morris Strawberry Thief in Houston Heights Powder Room

May 26, 2022

Originally, the whole room was this not-quite-milk-chocolate brown. Dark can look good in a small room like a powder room. But stark dark with no pattern is often claustrophobic.
Since this is a 100-year old bungalow with many layers of paint and potentially incompatible wall coatings, I was worried about unstable conditions inside the wall. Long story short, these conditions can lead to stress on the wall and delaminating layers, which also mean wallpaper seams that don’t stay down. Do a Search here to learn more.
So the homeowners agreed to have the walls lined, as a way to avoid these potential problems. Read previous post for more info.
The photo above shows the walls covered in the white liner.
Finished!
William Morris’s designs, and Strawberry Thief in particular, have been very popular the last two years or so.
His patterns are studies in symmetry and rhythm , and evoke the era of Art Nouveau and even Art Deco .
Last corner magically ended up with virtually no mis-match.

Morris & Co is the manufacturer. This is a nice, supple, non-woven material, and can be hung by pasting the wall , although I prefer to paste the paper. It has a vinyl coating and will be fairly washable – good for this family with a toddler. It’s also designed to strip off the wall easily and in one piece when it’s time to redecorate.
See previous post for a pic of the label of the liner paper.

Paint Peeling Off The Wall – A Bad Harbinger

March 16, 2022

Prior to prepping for wallpaper, I’ve removed a hanging shelf. It had stuck to the paint, and pulling the shelf off the wall also took some of the paint along with it.

This is a bad sign. If paint will release from the wall so easily, it’s an indicator of an unstable surface underneath, that the paint is not able to bond to.

That also bodes poorly for any coatings applied on top of it, such as my smoothing compound, primer, and wallpaper.

The most worrisome of these is wallpaper. Because unlike other substances, wallpaper expands when it gets wet with paste, and then as the paste dries, the paper shrinks a tad and puts stress / torque on the wall. If the underlying surface is unstable, these layers can actually pull apart, resulting in a ” popped ” seam.

This is not a ” loose ” seam and cannot be simply glued back together. It’s layers deep inside the wall coming apart / delaminating from each other, and virtually impossible to really repair.

So what causes this? Do a Search here to read my other posts on this topic. But causes can include incompatible surfaces, such as old oil-based paint covered with newer latex paint, gloss paint covered with new paint without proper prep / de-glossing, chalky or calcimine paint, or coatings applied to a dusty wall.

In all these cases, the top coatings won’t be able to adhere tightly, and can result in what you see here – the top layer(s) of paint pulling off the wall with just a little stress.

Even worse, in my world, is the potential of the surface beneath wallpaper seams coming away from the wall.

Kill Point Over Door, Ridge, More

February 25, 2022
After you’ve hung wallpaper on all the walls in a room, the point where your last strip meets up with the first strip is called the kill point . This virtually always ends up in a pattern mis-match. That’s why you engineer to place it in an inconspicuous place, such as behind a door.
This powder room, though, had no hidden corner or handy door. That meant that I would have a pattern mis-match a full 5′ high, to the left of the toilet you see here. I prefer to have the pattern match in a corner like this. As you can see – it does. I will explain how I accomplished that.
I decided to place the kill point over the door. Even though this space is 2′ high and a mis-match might be noticeable, not many people are looking up over the door, so it’s a better choice than in a 5′ or 9′ long corner.
The dark smudges on the wall in the photo are where I’ve spread paint, to prevent white walls from peeking out, should the dark wallpaper shrink as the paste dries.
Here I’ve positioned the strip on the left. This leaves a gap of about 3″. Once I match the new strip up to the piece on the right, its pattern will not match perfectly with the strip on the left.
Now I’ve positioned both strips, and the one on the right is overlapping the one on the left.
Here’s an idea of what the pattern mis-match will look like. To be honest, it’s not all that bad, with this busy pattern and being up over the door. Still, I thought I could make it look better.
I’m going to do a double cut , which is our installers’ fancy term for a splice. I’m going to cut through the two strips, splicing them together, cutting along the vertical foliage elements, to minimize cut-off motifs and to disguise the splice.
When double cutting on the wall, it’s really important that you slice through the two layers of wallpaper only , and not cut into the primer or wall surface beneath. This is because, if the wall surface becomes scored or compromised, when the wallpaper paste dries and the paper shrinks and pulls taught, it can put tension on the wall surface. If the surface is not intact, it can give way and actually come apart ( delaminate ), resulting in wallpaper that comes away from the wall – and there’s nothing beneath it to paste it back to.
I’ve blogged about this before, so do a Search here to learn more. It’s important!
Anyway, to protect the wall beneath where I will make my splice cut, I’ve placed three layers of scrap wallpaper, to pad the wall. I figure I can cut through the two top layers, but not all five.
Note that three layers of non-woven material have some thickness, and can “throw off” the splice cut and prevent the top two strips from fitting together perfectly. In this case, the paper is flexible enough that I’m not worried about that particular scenario.
The strips are in place, and I’m ready to make my cut. I prefer to use a single-edged razor blade held in my fingers, rather than a blade-holder. What’s most important is that the blade be brand new and spankin’ sharp!
Here I’ve made my cut and am removing excess paper from the right side of the top strip. Look carefully and you can see how my razor blade followed the contours of the vertical foliage design elements.
Here I’ve removed the excess paper from the left edge of the bottom strip. You can see they are poised to fit together nicely.
Before fitting the two strips back together, though, I’m examining the wall surface. Check the photo carefully, and you’ll see that I did, after all, score into the primer. 😦 The surface below is skim-coat that was used to smooth a textured wall – and another potential layer that may come apart when exposed to tension from the drying wallpaper.
Shoulda used a Boggess Strip. https://www.steveboggesspaperhanging.com/lexanpage.htm
One way to prevent the wall from delaminating is to put something over the compromised area, to distribute the tension of the drying paper and take it away from the cut wall. Here I’ve taken a scrap of wallpaper, which is a tough non-woven material, and carefully peeled the printed surface from the white substrate (no pic of that process). Now I have a thin material that I can use to pad the wall.
I’m using the black printed side facing out, in case the spliced strips shrink a little – anything peeping out will be black and not noticeable.
Here is the bit of paper in place, spanning across the cut on the wall.
Now I’ve smoothed the two top strips back into place. Since my double cut followed along the vertical foliage elements as much as possible, and because I cut around the gold flowers to keep them full and round, the pattern looks like it matches up just about perfectly.
But wait! … What’s that lump / ridge under the wallpaper, the full height of the seam? That’s my seam padding! Doesn’t look great.
I’m really surprised at this. The non-woven wallpaper material is thick. But that’s why I pulled the top and bottom layers apart, to make my patch piece thinner. I guess not thin enough. Once dried, this ridge is going to be obvious.
But, to be honest, this is up over a door where no one’s going to be spending much time looking. In addition, once I get my 100 watt light bulb out of there and replace the homeowners’ original, small light fixture, this bump under the wallpaper will be pretty much indiscernable.
Still, that lump was buggin’ me. Another invention from my colleague Steve Bogges to the rescue! Pictured is his seam tape , which was made specifically for this type situation. This is very thin – yet strong – paper tape that is used to bridge cut areas like this, and prevent tension from drying wallpaper from tugging at unstable walls.
The tape has a pre-pasted side (the gloss you see), and feathered edges, to make it less noticeable under wallpaper.
Hard to see, but here I’ve placed the seam tape over the cut wall areas
Now the two top strips have been smoothed back into place. Amazingly, no bump from the seam tape beneath shows. And the pattern mis-match is barely visible, too.
Win-win!
All that’s left to do is to wipe paste off the surface of the wallpaper. This overlapping and splicing does mean that wallpaper paste will get on the surface of the strip underneath. Actually, there is a way to prevent that, and it also involves products from Steve Boggess
But … that’s a blog post for another day …
This pattern is called Peonies and is by Rifle Paper.

This Week’s Delaminating Walls – Finished Project

January 16, 2022
Re my two previous posts, once the wall was repaired and a liner hung, the next step was to hang the wallpaper. It went up beautifully, and the seams are invisible. No way the seams can open up again!
This pattern is called Brooklyn Toile, and is by Flavor Paper, and is in their EZ Vapes line, which is a pre-pasted paper that goes up easily and also will strip off the wall easily when you redecorate. I liked it a lot.
And many thanks to Flavor Paper, who helped make the replacement paper a little more affordable for this new family and their precious baby boy.

All told, it took me three days to strip the wallpaper, repair the surface, and replace the paper on just one wall plus a few short strips over two doors. There are, of course, charges for materials and labor to factor in. Much better to anticipate this potential problem ahead of time and take steps to prevent it. Liner, seam tape, overlapped seams are all good options.

More Work on Yesterday’s Delaminating Wall

January 15, 2022
Re yesterday’s post … after I got the wall stabilized, I skim-floated the surface to smooth it. That dried overnight, and today I sanded it smooth, vacuumed up the dust and then wiped residual dust off the wall with a damp sponge, and then primed with good old Gardz. I feel pretty confident that that wall is secure enough to withstand the tension of drying wallpaper. But, just to be sure, I applied a liner. A liner is a special paper that goes on the wall under the decorative wallpaper. In this case, the purpose is to distribute tension so that no stress is placed directly on the wall. So it’s important that the seams of the liner and the decorative wallpaper do not line up or fall on top of each other. This way any tension is dispersed and distributed, and any inner surface that wants to delaminate will be held in place by the layers of paper over it. In this photo, the section to the left has the new white liner, and I am moving toward the right to finish this wall.
t’s important that the liner be flat and that the seams lie down tightly, so no bumps or ridges show under the new wallpaper. I was really pleased with how these seams just melted away.
There are all kinds of liner papers out there. This one is a stiff, somewhat thin non-woven option made in Germany.
Using a liner does add to the cost of the installation, for both material and labor to hang it.

Wallpaper Coming Off – Delaminating Wall

January 14, 2022

An Unfortunate Situation

This Brooklyn Toile wallpaper by Flavor Paper on an accent wall in a nursery went up beautifully. The contractor had added new Sheetrock to one wall, and painted the other, old/original wall. I skim-floated both walls and sanded smooth, primed, and hung the wallpaper. Perfect! (Search here to see my original post.) But within less than a month, the homeowner contacted me and said that the wallpaper was ” coming off the wall .” It was a 1920’s bungalow in the Woodland Heights neighborhood of Houston. And therein lies the brunt of the problem.
The wallpaper itself is not ” coming off the wall .” What’s happening is that the wall surface itself is coming apart – or, delaminating . This is because multiple layers of paint and other substances on the wall may not be compatible. A probably scenario: In 1920 oil-based paint was used. Later someone rolled on a coat of latex paint. Then the homeowners redecorated and used gloss paint. Then some ” flippers ” who had watched too much HGTV slapped on more paint without bothering to de-gloss or prime first. And somewhere in the mix you’ve got cheap paint and dust and other incompatible materials.
Over time, and especially when stress is put on the wall surface, such as when wet wallpaper paste dries and the paper shrinks, this stress can tug at the wall and actually pull these layers apart. There are other contributing factors, too, such as humidity, temperature, and location. I find it interesting that the worst parts of the affected seams were toward the top of the wall. This speaks of heat, humidity, and forced air (either hot or cold) coming out of the air vent just to the right of this wall. This photo is of the area over a door, very close to the air vent.
See how thick that is? It’s not just the wallpaper. There are several layers of wall coming apart. Some layers are clinging to the back of the wallpaper, and some are staying stuck to the wall.
Multiple layers, many years of coatings on this wall.
Easy to see the many layers. The paper itself, my blue primer, my layer of smoothing compound, paint, more paint coming off the wall. Then multiple layers of paint and texture still clinging to the wall. This shot is just below the ceiling.
Same thing happening at the baseboard at the floor.
Layers of paint separating from the wall in chunks. Some pulled off easily, and some I had to chop off with my 3″ putty knife.
Most of the paint and unstable surface material clung to the back of the wallpaper. This pile is just three strips – only half the wall. But it’s thick and stiff and heavy because of the paint stuck to the back of the wallpaper. There was so much and it was so heavy and bulky that I had to carry it out to my van in two trips. When I got home, it totally filled my trash bin.
Here’s the wall once all the other layers came off. Brushing my hand over it revealed a layer of dust. No wonder the paint and other coatings wouldn’t stick. Nothing sticks to dust. It’s like flouring a cake pan… The paint or wallpaper will kinda stick – but won’t really stick. Paint on top may be fine. But add a little stress from drying / shrinking wallpaper, and you may end up with layers that pull apart.
Wiping the walls with a damp sponge removed a lot more dust. But the wall still felt chalky. Whatever type of paint this was, it was not holding together.
I had to stabilize this chalky surface. Enter Gardz, a wonderful product – Gardz is a thin, penetrating sealer that soaks into porous surfaces and binds substances together. It dries hard and creates an intact surface. The darker area in the picture is where I’ve rolled on a test area. Gardz is thin like water, and it runs and drips and splatters. It’s imperative that you cover floors, countertops, and baseboards, and roll carefully, and roll upward rather than downward, to minimize runs and drips. A microfiber roller holds the liquid well, and reduces drips.
Gardz is made by Zinsser.
No photo of the finished wall, but I was very pleased with the stability of the surface. No more chalk or dust. Now, there still could be unstable or incompatible layers deeper inside the wall. (Latex paint over oil without proper prep.) But for now I feel pretty confident that this wall is solid and will hold up to the next process in preparation for getting the new wallpaper up.

Don’t Use Adhesive Picture Hangers

January 6, 2022
Yes, they’re strong enough to hold a 50lb painting.
But removing them may well take layer(s) of paint along with! Here you see a bubble that has lifted from the wall, as well as a break in the paint that was torn off by the adhesive picture hanger.
Several layers of paint have been pulled away from the wall. This is called ” delaminating .”
One reason for this is because the original underlying surface may have been dusty – as in dust from construction, or from sanding new drywall joint compound. Nothing sticks to dust. Other reasons for delaminating walls are incompatible surfaces, such as, an older home that starts out with oil-based paint, then someone comes along and applies latex paint over it without proper prep, then someone adds a gloss paint, then a ” flipper ” buys the house and slaps on a coat of paint without deglossing, ,,, on and on, situations that can cause layers of paint to not stick to each other. End result is that the wallpaper may come away from the wall, too.

Re Yesterday’s Post – Tricks to Stave off Wall Delamination

October 14, 2021
One way to (hopefully) prevent an unstable wall from delaminating to to hang a liner paper. A liner is a special paper that goes on first, and your finish paper goes on top. Usually, liners are hung horizontally rather than vertically. The idea is that the seams of the two papers will not line up, so that eliminates the worry of stress from drying and shrinking wallpaper tugging at the wall surface below. But liners add more materials cost, and also labor cost to hang it, plus time, because it has to dry overnight. This homeowner had already shelled out a lot of money for this Schumacher (high end brand) “Acanthus” pattern. So I devised a method to do a “mini-liner” effect. I took liner paper and cut 2″ strips, and applied them to the wall under where the seams would fall.
Here I am using my laser level to mark where the next seam would fall. Next I rolled paste on the wall, and then I applied the strip of liner paper. The liner will straddle the area where the seam lands, and thus disperse the tension on the wall across its width. Any stress put on the unstable wall will be covered by the liner strip and by the wallpaper, hopefully preventing any chance of delamination (the wall coming apart).
I like the product I used today because it’s “non-woven” material, which has a high polyester content and shouldn’t shrink or tear. But it’s not as thin as I thought … I had hoped the thin strips would be undetectable under the textured grasscloth. But I was disappointed that, in certain lighting, the vertical ridges from this very thin material do show a tiny bit. I was unable to go back and open the seam and remove the strips, because – you guessed it – the surfaces of the wall began to come apart. Tomorrow I will try a different material.
The next day I tried a trick recommended by colleagues on my paperhanger’s Facebook page – to use cash register receipt print-out tape, available at office supply stores. This material is a lot thinner – but it is also not nearly as strong. I hope it holds up to the tension placed on the seams by the wallpaper. It is thin, and much less noticeable under the textured grasscloth … although I did see one area where the vertical ridge was just just barely detectable under the paper.

This is a grasscloth pattern called ” Acanthus ” by Schumacher.

Why Are These Seams Pouching Up?

November 4, 2020

There are a couple of issues going on in this master bathroom, causing the wallpaper to curl at the seams and the layers to delaminate.

For starters, the previous installer did not bother to remove the original wallpaper, but hung on top of it. He did prime over the original wallpaper, which is good,,,, but that primer felt too slick to provide a good surface for the new wallpaper to stick to. I have a feeling it was not formulated for wallpaper.

Second, there has been a lot of steam and humidity in this room over about 15 years. This particular type of paper does allow moisture to find its way into the seams, causing curling and delaminating.

These pre-pasted, paper-backed, solid vinyl wallpapers are among my very least favorites.

Read more about this material by clicking the link below.

https://wallpaperlady.wordpress.com/stay-away-from-pre-pasted-paper-backed-solid-vinyl-wallpapers/