Humidity Causes Curling Edges on Vinyl / Non-Woven Wallpaper

I hung this wallpaper about 10 years ago. It’s a main bathroom in a 1920’s home in the Woodland Heights neighborhood of Houston. The home has been remodeled including updated HVAC systems , but surely still suffering from issues of humidity and air circulation.
At some point, the very edges of the wallpaper started curling back at the seams. This is more pronounced at the upper portions of the wall than at the chair rail. Meaning, humidity from showering is rising into the air, collecting under the ceiling, and working its way into the seams.
Once humidity gets into the backing of the wallpaper, it can cause the backing to expand. When that happens, the paper has to go somewhere. So it pushes itself away from the wall. Hence the curling that you see here.
What’s odd to me is that this happened with a paper that’s on a non-woven backing. Non-wovens are 20% polyester, so pretty resistant to moisture and humidity. I’m guessing that this company used less than the industry standard of 20% polyester. The material was super thin and flexible, which is unlike most non-wovens I’ve worked with.

I was able to make this look pretty good again. I used a putty knife to gently lift the compromised edges away from the wall, and then I worked some of my regular wallpaper paste back behind there. (no super glue or heavy duty paste or contact cement )
Then I used my heat gun – set on Low – to gently warm up the vinyl surface of the wallpaper . The heat gun served several purposes … It helped speed the drying of the paste , so it got tacky and held more quickly and firmly. The heat gun also ” melted ” the vinyl surface a wee bit, so it would curl back in the opposite direction.
I used a 3″ stiff metal putty knife to push the two edges of wallpaper back down to the wall. The metal knife heated up, too, and helped to get the vinyl to conform.
Using the heat gun and the metal putty knife also helped the two edges from the two strips to meet up together … sort of like two mountain big horn sheep butting their heads together . Butted together this way is better than one lying on top of the other.
I was really pleased with how well this worked. Sorry – no pics!

The brand is Super Fresco Easy .

Good Catch After a Mistake

Whoops! Somebody (me 😦 ) cut a wallpaper strip to 6’24” instead of 6’34”.

This William Morris wallpaper is expensive, and I didn’t want to just throw away the too-short piece. So I figured a way to use scraps to save it.

At the bottom of the too-short strip, I trimmed horizontally along an element of the design. From the scrap pile, I found a piece with a corresponding pattern, made sure it was the right length to reach the baseboard, and then trimmed the top horizontally to match up with the design on the piece already on the wall.

The reason I trimmed along the swoopy line of the design is that I wanted to eliminate a straight horizontal ridge showing under the two strips once they were overlapped on the wall. The eye might notice a wide, non-conforming, horizontal ridge, but it won’t notice a narrow overlap that follows the contours of the pattern.

I put the short strip in place, and the pattern matched perfectly.

But there was a slight sheen from above, glinting off of the cut edge of the wallpaper in just a few spots. You can just barely see this in the second-to-last photo.

So I pulled the two strips of wallpaper apart and put them back together, but reversed the sequence, overlapping the top strip onto the lower strip. Now there was no cut edge for light to catch or bounce off of, and now the overlap / ridge is completely invisible.

Note that the surface of this wallpaper was a vinyl (plastic) material. Wallpaper paste won’t stick to plastic very well (it’s too slick). There is a special adhesive called VOV – for Vinyl Over Vinyl – formulated to make this bond. But I don’t always trust it.

So I often use clear caulk, which I call Super Glue for Wallpaper. Under the right conditions, it’s a wonderful solution.

Note: There is a technique called a double-cut, which is a method of splicing two strips of wallpaper together. A double-cut eliminates the possibly-visible ridge that you get when you overlap strips of wallpaper. For various reasons too complicated to get into here, in this case, and especially down low and behind the toilet, I preferred to use the overlap-and-super-glue technique.