Posts Tagged ‘porous’

Fixing Drywall Damage From Where Vanity Was Removed

January 20, 2022
The powder room in this 1990’s home in the Houston Heights is being updated, and that means replacing the wall-to-wall vanity. Here the vanity has been ripped out. The areas where the backsplash was adhered to the wall have pulled the top surface of the drywall off. In addition, the plumber had to cut out a section of drywall in order to gain access to the pipes, so he can install the new faucet and handles. You can see the connections roughed in.
You can’t hang wallpaper over this mess. First of all, it way too uneven – all those bumps will show under the new wallpaper. And the outline of the ” trapdoor ” will leave a big square ridge under the paper. Thankfully, the plumber secured the panel with drywall screws – most plumbers just leave you with a chunk of drywall floating in space, or even just an empty hole.
Back to patching issues … in addition, the torn areas of drywall will absorb moisture from the wallpaper primer and / or paste and expand, creating bubbles that will show under the new paper.
I needed to fill in dips and gouges, even out high areas, and prevent bubbling drywall.
Gardz by Zinsser to the rescue! This is a penetrating sealer that soaks into porous surfaces and then dries hard, binding them together and creating a stable surface, as well as resisting moisture from water-based top coatings.
This picture doesn’t look much different, but here the torn drywall is a little darker, indicating that the Gardz has soaked in and dried. The surface is now ready for a skim-coat.
But first, the trap door needs to be addressed. I covered the cut areas with four strips of self-adhesive mesh drywall tape (no photo).
Then I went over everything (wall to wall) with joint compound (commonly referred to as mud ) (no photo).
Because of the thickness of the high and low areas, this had to be a thick coat of smoothing compound, and would take a long time to dry. So I went to the jobsite two days ahead of our install date, to do these initial repairs.
And – no – you can’t use quick set or hot mud or 5 or 20 minute mud to do these repairs. These products are intended for repairs of small areas. Top coatings like primers, paint, and wallpaper paste do not stick well to them. Don’t let a contractor sweet-talk you into letting him use any of these to smooth a large area of wall.
Here is the wall after my first, heavy, coat of smoothing compound. I use Sheetrock brand’s Plus 3.
The bubbles you see just left of center show that Gardz didn’t 100% do its job of sealing out moisture, as a little expansion and blistering has occurred. Not a biggie. These will disappear when the surface is sanded. There is usually not a problem with these re-appearing.
When I got to work two days later, the smoothing compound had dried. I sanded pretty smooth. Then vacuumed up the dust on the floor, and then used a damp sponge to wipe residual dust off the wall. This is important, because no coating will stick to dust.
The wall still wasn’t perfectly smooth, so I did another skim-coat. This was much thinner, so didn’t need a lot of time to dry. I used a fan and my heat gun to speed things along.
Once that was dry, I sanded it smooth, vacuumed and then wiped off all dust. Then rolled on my favorite wallpaper primer Roman Pro 977 Ultra Prime. I have the paint store (Murphy Brothers in central Houston) add a little blue tint, so I can see it when I apply it to the wall.
What a transformation! Now this wall is ready for wallpaper!

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.

Going For More Of The Same

February 9, 2021

I hung the original wallpaper in 2014, when the house was first built. The PEX water lines used in the home (flexible hoses instead of PVC pipes) were new at the time. Tragically, after a few years, the lines used in this home failed and caused leaks all over the house. Replacing all the water lines required cutting holes in MANY places throughout the home.

You can see in the photos where the plumbers cut out drywall and then patched it back in. This company actually did a good job of removing the wallpaper in the areas of their repairs.

Unfortunately, with the amount of wallpaper that was left over from 2014, I was not able to do repairs. The entire room had to be repapered.

The homeowner loved the pattern and wanted to keep it. It was still available, so she bought enough to repaper the room.

For various reasons, the original wallpaper was much more difficult to get off the wall than I expected. I could have gotten it off – but it would have taken about two full days.

So I opted to hang over it. It’s important to skim-float over the seam areas. First, because the seams will leave a little ridge that will telegraph through and show under the new paper. But also, because as wallpaper dries, it shrinks and puts tension on the seams. There is always the potential that this tension will cause the the surface below to pull away from the wall, and especially so if there is a weak area such as a seam. So you always want to avoid putting a seam on top of a seam.

So I skim-floated (do a Search here to learn more) over the seams, as well as over the patched areas left by the plumbers. See photos. Then I sealed the walls with Gardz, a product that penetrates and seals porous materials – like drywall joint compound and like this traditional British pulp wallpaper. Because it soaks in and dries hard, it helps to prevent moisture from paint or wallpaper paste from soaking through, and thus prevents bubbling of the underlying surface. That’s why this product is primarily used for sealing torn layers of drywall.

Although a bit glossy for my liking, Gardz is also a good primer to hang wallpaper on.

Interestingly, the expansion rate of the new wallpaper was a bit less than the original, and so the seams fell about 1/4″ to the right of the original seams. This reduced the worry of seams falling on top of seams and causing lifting.

It was a complicated room, and the paper was thick and stiff and difficult to work with. Prep took one day, and it took me two additional days to hang the paper (16 single rolls – 8 double roll bolts).

The wallpaper is in the line of Nina Campbell, by Osborne & Little, a British company. While most British papers these days are printed on an agreeable non-woven substrate, this one is a traditional, old-school British pulp … thick, stiff, difficult to fit into turns and angles, easy to tear, easily stained, non-malleable, plus the factory’s trimming roller blades must have been dull or wobbly, because the edges were not cut perfectly straight, which meant the seams had some “gaps and overlaps.”

Still, the finished room did look pretty darned good – even if it looks exactly the same as it did in 2014.

But that’s exactly what the homeowner wanted. So all is good and mission accomplished!

Patch Disguises Delaminated Wall

December 19, 2018

I hung this paper for a young couple in a cute 1930 bungalow in the Heights neighborhood of Houston a year or two ago. After a year or so, the wallpaper began to gap at the seams. Turns out this is not the wallpaper coming loose from the wall. What is happening is that the various layers of paint and etc. inside the wall are actually coming apart.

The wallpaper dried and shrank and put torque (tension) on the wall at the seams. Also factoring in is humidity in the air, poor air circulation in the air, and possibly a moisture problem inside this wall. Oh, and this wallpaper manufacturer, Hygge & West, is known for using inks that curl away from the wall at the points where they cross the seams.

But the real culprit is years’ worth of paint and other wall surfaces that are not compatible with one another. Back 80 years ago, you had oil-based paint. Cover that with latex paint, then do a project that creates dust that sifts onto the walls, add some gloss paint, roll on a coat of latex, then a layer of texture, then more paint … all without proper prep between.

Proper prep or not, most of these wall coatings are not prepared to adhere to one another, and when drying / shrinking wallpaper puts stress on the surface, the various layers can let go from one anther and “delaminate” – which means to come apart.

In the photo, you can see the thickness of the separating layers. Some layers of paint have held fast to the wall, but others have let go and curled back. Because there is dust and gloss and other factors underneath, it’s not guaranteed that anything will hold the layers back tight to the wall.

Adhesive silicone caulk was my glue of choice. It will stick to porous or glossy surfaces. I squeezed some carefully into the popped seams, spread it around, closed the seam back up, and then waited for the caulk to tack up and grab ahold of the layer above it.

Eventually the caulk dried enough and became tacky enough that it held the layers together. Not perfectly, but at least there was no gaping opening at the seam.

The gap and a slight “pouch” still showed, so I thought of covering them with a patch that would span the seam, holding both sides together.

So next I took some left over paper (ALWAYS save your left overs!) and cut out dark green palm leaves. I made sure to leave a wide section on either side that was cut along the individual fronds, so they would mimic the pattern on the wall, and so there would be a wide area to straddle the seam and add stability. The area I cut out between each front helped the patch blend in with the pattern that was on the existing paper on the wall.

The stupid camera ate my picture of the patch after it was cut and pasted, but before it was applied to the wall. Dang it, because that would have explained a lot of my process.

Anyway, I made several of these frond-leaved patches, pasted them, and then applied them to the wall, directly straddling the popped seams. Not only did this cover and hide the open edges of the seams, but the width of the patch helped strengthen the bond while at the same time lessening the possibility that a seam would open up again.

In the last photo,  at the top of the picture, you can see one appliqué patch applied, straddling the seam.  Moving down the wall, I would add two more similar patches over the seam.

From a distance – heck, even from up close, you could not see the repaired areas.

Wall Sealing Whoops

September 26, 2018


Today I prepped a room where the drywall had been badly torn when the old wallpaper was stripped off. This happened because the original installer hung the wallpaper directly on the drywall, with no coat of paint or primer to protect the drywall.

Before I could smooth the wall surface, I had to seal the torn drywall, because moisture on the torn areas would cause the brown paper to bubble. I rolled on a heavy coat of Gardz, a water-thin, penetrating product that is designed to soak into the porous material, bind everything together, and dry hard. It is supposed to dry inpenetrable by water.

Once it was dry, I skimmed over it with joint compound (which will be sanded smooth later).

As you can see, the Gardz failed to do as claimed, and it allowed moisture from my smoothing compound to seep through it and enter the torn paper of the drywall, which then expanded and bubbled. I’ve got a big mess on my hands!

Tomorrow, when everything is dry, I will sand smooth. Usually bubbles like this dry out and then sand flat. But the large loose areas have me a little worried. They may still be loose and bubbled, and they may swell again when the wall is given its final coat of Gardz.

I may end up having to cut out some loose areas, refloat, and reprime.

Not good, because this could add a full day to this job, and because there could potentially still be unstable areas under the surface. Never good to have an unsecure surface under your wallpaper.

Stay Away From Paper-Backed Solid Vinyl Wallpapers

February 21, 2018

Wallpaper - Curlinig Seam, Paper-Backed Solid Vinyl, Mylar
Paper-backed solid vinyl papers are about my least favorite of all papers. The main reason is that they tend to curl at the seams, especially when there is humidity present.

The issue is that, IMO, the gritty manila-type paper backing is porous, and so it will pull moisture and humidity out of the air when the room is under humid conditions (teenagers taking long hot showers). Once this happens, humidity / moisture can enter the seam and soak into the paper backing, the vinyl surface can delaminate (come apart) from the paper backing, causing the surface to curl away from the substrate / backing. This is what you see in the photo.

Because the two layers of the wallpaper have actually come apart, it is also very difficult to paste back against the wall. It would be far better to remove all the wallpaper, properly prep the surface (smooth, primer), and then hang the new wallpaper.

Using 20-Minute “Mud” to Repair Sheetrock Damage

March 31, 2017

Digital Image

Digital Image


When the homeowners had their powder room vanity top replaced, the shorter new backsplash left a 1″ area of torn drywall around the top of the new backsplash. There was a height difference between the drywall and the wall (which was covered with at least two layers of old wallpaper). This needed to be evened out before the new wallpaper could go up.

Because torn drywall will bubble when it gets wet, I used a penetrating sealer called Gardz to prevent this by sealing the raw area. Once that was dry, I used 20-minute joint compound to “float” over the damaged areas.

The bag says “5” (see photo), but that is misleading. What they mean is that you have five minutes to mix the powdered material with water, stir smooth, and then work with the stuff, before it gets stiff and hard. The actual drying time is more like 10-20 minutes, and sometimes longer.

Once it’s dry, it can be sanded smooth. Wipe off the dust with damp sponge, let dry again. Then it can be sealed with a primer, and I like the penetrating sealer Gardz, once again, to seal this porous joint compound material.