Posts Tagged ‘porous’

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.