Posts Tagged ‘unstable’

Trick in Hopes to Stave Off Popped Seams from a Crumbly Wall

April 3, 2019


The walls in this powder room in the West U neighborhood of Houston had had many treatments over it’s life, including paint, more paint, skim-floating, wallpaper, and more. Sometimes, and particularly if prep is not done properly, these various layers are not compatible, and won’t adhere to one another well.

When the old wallpaper was removed, this was clear at the seams, where the various layers of the wall had pulled apart, leaving ridges along the length of each seam. This happens because the wallpaper dries and pulls taught and creates tension on the wall; if the wall is unstable, the layers can be pulled apart (delaminate). Sorry, no pics of the “before,” but you can do a search here to see pics of other rooms. This condition can happen over time, as the house fills with humidity and the paper absorbs it, then dries and shrinks again.

I dug out the raised ridges and applied tape over them, sealed with Gardz, a penetrating sealer that dries hard. Then I skim-floated over all the walls, to create a smooth surface for the wallpaper. Sanded, wiped dust off with a damp sponge (nothing sticks to dust), and primed all walls with Gardz.

One good way to deal prevent this from happening again is to cross-line the walls with a special liner paper. This is a thin paper that is usually run horizontally before the actual decorative paper is hung. The idea is that if the new paper shrinks and applies tension, it will be distributed by the liner paper, and will not pull at the wall. If the liner shrinks and pulls, the tension is off-set by the decorative paper on top of it. So the two layers are working together to distribute any harmful tension on the wall surface.

Unfortunately, using liner adds a day of labor plus the cost of the material. The homeowner’s budget had already been busted by other factors, so she wanted to keep the job to one day. After collaborating with my colleagues in the Wallcovering Installers Association on our Facebook page, I decided to try this method:

From Office Max I got some plain old cash register tape. I plotted where each seam would fall, and used my laser level to guide placement of a floor-to-ceiling strip of the tape. I adhered it with regular wallpaper paste. At first, I worried that it would soak up moisture and bubble, but once it was smoothed into place, it laid down nice and flat.

Then I hung the wallpaper. The seams fell nicely on top of the tape, held tightly, and looked beautiful. There is the possibility of seeing a very slight ridge under the paper because of the thickness of the tape, but it’s very minimal because the tape is quite thin. And it’s much preferable to popped seams or delaminated walls.

The idea is that the tape will bridge the seam, and distribute tension from the drying paper across the width of the tape, keeping tension away from the wall itself. The tape is very thin, and doesn’t appear to have much tensile strength, but my buddies who have tried this method say it works well.

Time will tell, but I have a lot of confidence in this method.

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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.

A Good Reason Not to Double-Cut

April 10, 2017

Digital Image

Digital Image


A double-cut is a paperhanger’s term for splicing two strips of wallpaper together. The edges of the strips are overlapped about 1″ on the wall, and then, bracing against a straightedge, a sharp razor blade and plenty of pressure are used to cut through both layers of wallpaper. Remove excess paper from both layers, and you have a perfectly butted seam.

The only problem is that it’s virtually impossible to do this without scoring into the wall, slicing through the top layer (or more). This cut makes the surface unstable, and when the new wallpaper dries, it shrinks and puts tension (torque) on the wall’s surface. This shrinking and tension can cause the wall to split and curl back, leaving a gap or a gaping wallpaper seam.

This is what you see in the photo.

To remedy this, I wanted to bridge the gap with something that would move with any shifting in the drywall, and that would not cause ridges under the new paper.

The new wallpaper was a thick, textured material, so I was not overly worried about ridges from the patch telegraphing through it.

I used strips from the paper backing of the old wallpaper / grasscloth I had just stripped off the wall to cover the cut wall areas. I tore the patches, rather than cutting, because the “feathered” edges of the torn paper would be less noticeable under the new paper than a sharp, straight edge would be.

The strips were wet from having been stripped off the wall with water, and the wall’s surface had damp paste residue remaining on it, so the patching strips adhered nicely to the wall surface.

But, to be sure, I brushed on Gardz, a penetrating sealer and “problem wall solver.” It soaked in, bound the surfaces together, dried, and made a taught, strong surface for the new wallpaper to go over.

Still, I made sure that my seams did not fall in the same exact spots as these compromised areas of wall. That greatly reduces the possibility of seams in the new wallpaper from curling back or pulling away from the wall.

As it turns out, because of the way I engineered the wall and various other factors, I did end up doing a double cut splice over this door. But I made sure it was not in the same place as the compromised wall surface. In addition, I protected the wall by putting a thin polystyrene (plastic) strip under the wallpaper before I cut, so that when I pressed my razor blade hard to cut through the two layers of cork, it did not damage the wall. Sorry, no pics, but there are other photos of that process on my blog, if you want to do a Search.