Posts Tagged ‘expands’

Preventing White From Showing At The Seams

March 10, 2022
When wallpaper gets wet with paste, it expands a bit. And when it dries, it can shrink just a tad. That teeny gap at the seams can expose the wall underneath it. This can happen even with the non-woven materials, which are supposed to be dimensionally stable.
In addition, manufacturers usually print on a white substrate, so sometimes you see the edges of the paper at the seams, too.
All this is much more noticeable on a dark paper, such as here.
One thing I do to prevent / minimize this is to strip the wall with dark paint under where the seams will fall. So even if a seam opens up a bit, you’ll see dark, not white.
Since non-woven wallpapers don’t expand (much), it’s easy to measure the width of your strips and plot where the seams will fall, use a level, and then apply the paint.
I use plain old craft paint from the hobby store. I use a scrap of sponge and dip that in water (in my orange bottle cap) then into the paint, and then run my stripe down the plumb line I’ve drawn on the wall or used my laser level to shoot a vertical line.
It’s important to not get the paint too heavy or thick, because the wallpaper paste may not want to grab ahold of paint like it wants to hold on to a wallpaper primer. And definitely don’t use a gloss paint.
Be sure that it’s good and dry before you hang the wallpaper. A heat gun will speed things along if needed.
Not pictured, but you can look up other posts here … I also take a bit of chalk of a corresponding color and run it along the edge of the wallpaper to cover up that white edge. It’s important to apply the chalk from the back, to avoid getting any on the front of the wallpaper. Some colleagues use water markers, pencils, or gouache paint. Whatever you use, do not use anything with oil-based inks or colors. These will bleed and stain your wallpaper.
Chalking the edges is more important than striping the wall, IMO.
This pattern is called Allure and is by Graham & Brown , a brand I like a lot.

Fitting a Wide Strip into a Narrow Wall Space in a Corner

February 18, 2022
I have to cover 15″ width of wall with a strip of wallpaper that is 27″ wide. Working with that 27″ wide strip and pushing it into the corner, and getting paste all over the woodwork, and trying to not get creases in the paper … all very difficult.
My solution is to trim the wallpaper to fit the corner. Here the strip has already been cut, pasted, and booked (folded pasted-side-to-pasted-side). I’ve determined that I want the new strip to be 15″ wide. This will allow enough to cover the wall space, plus the 1/2″ inside the little space between the wall and the door trim.
Because wallpaper expands when it gets wet with paste, to get an accurate measurement, I’m trimming after the strip has been cut, pasted, and booked for a few minutes, and has expanded to its maximum.
This is called wet trimming. Alternately, dry trimming is when you measure and trim an unpasted and unfolded strip.
My straightedge is set at 15″ from the left edge of the wallpaper. I’ve used a single edge razor blade to make the cut.
Here is the strip in position on the wall. I’m using a plastic trapezoid squeegee wallpaper smoother to push the right edge into the small space between the wall and the door molding.
You can see how nicely the wallpaper wraps around the corner and tucks into that narrow space.
The pattern is called Garden Party and is by Rifle Paper, which is made by York, one of my favorite companies.

Preventing White Wall From Showing

January 23, 2022
Wallpaper expands a bit when it gets wet with wallpaper paste (3/8″ in this case), and then shrinks when it dries. This can result in the white edges of the paper showing, or the wall behind peeking out from teeny gaps. With a dark paper like this, it can be noticeable. I ran a piece of black chalk along both edges of the paper to cover the white substrate (no photo). It’s important to use chalk and not oil pastel, as oil will stain wallpaper.
Then, to keep the the wall from peeping through, I striped the area on the wall under where the seams would fall with black paint. Not shown, I used my heat gun to speed along the drying of this stripe. I don’t make the paint too thick, because you want the wallpaper seams sticking to the wallpaper primer, not to the paint.
All this takes a good bit of time. Also, it’s tricky to plot ahead, because, due to the expansion factor, it’s difficult to know exactly where the seams are going to fall. Non-woven materials don’t expand, but papers like this one will.
I use paint from the hobby store or Texas Art Supply, run along the wall with a small chunk of sponge, dipped in water.

Paint Stripes to Prevent White Wall Peeking Out

January 8, 2022
Sometimes (usually) wallpaper expands when it gets wet with paste and then shrinks just a tad when it dries. This can result in hair-breadth gaps at the seams. Usually not a big deal. But when the paper is dark and the sub-surface is light, you can end up with white wall visible at the seams.
So sometimes I’ll paint a stripe of matching color behind where the seams will lie. Measure to plot where the seam will fall, then use a level and pencil, or a laser level, to indicate where, and then run a stripe of paint along that line. Make the stripe wide enough to accommodate slight variations in measurements and wallpaper expansion.
I use craft paint from the hobby store or Texas Art Supply. The photo shows an outdoor paint – not the best option, but it’s what I had in the truck. 🙂 I use a small rectangle of sponge dipped in water and then in the paint.
For extra assurance, on thick papers, dark surface printed on a white backing, you can also use artist’s chalk pastels (chalk only and NOT oil pastels) to color the edges of the seams. Do a Search here (upper right corner) to find previous posts about that.

“Priming” Wall With Paste to Keep Seams Down Tight

August 3, 2021
Hard to see, but the slightly darker, shiny section of wall to the left of the wallpaper is a bit of paste that I have rolled onto the wall along where a seam will lie.
The paste has pulled the edges of the paper nice and tight to the wall. Never mind the slight pattern mis-match … this is a hand screen print, and it’s pretty common for these to be slightly off in printing and/or trimming. The pattern matched better above the door, then drifted off as the paper neared the bottom of the strip. You can also see that some of the edges are somewhat jagged and saw-dusty, due to trimming at the factory.

Some manufacturers use inks that fight with their substrates. The substrate absorbs moisture from the paste and expands, but the inked layer does not, so you end up with the bottom layer stretching and forcing the top layer to curl back, resulting in edges that curl and don’t stay tight to the wall.

Any time you smell ink that calls to mind mothballs, you can expect to deal with this issue. It’s pretty common with screen printed wallpapers.

One trick is to lightly sponge the surface with water before pasting the back. Another, which I have discussed here previously, is to paste the paper, fold and book it, and then dip the rolled-up edges into 1/4″ of clean water. Then place the rolled up strip into a plastic trash bag for the booking period. This helps to keep the edges from drying out while the paper books.

On many papers, I’ve found that it also helps to roll a light coat of paste onto the wall, just under where the seams will fall. This works amazingly well to grab the edges and hold them tightly against the wall.

Compensating Around A Window

June 29, 2021

Going around windows, especially wide windows, can be tricky. Wallpaper expands, it twists, the design can travel up or down from the ceiling line – and all this can go on independently of each other, with the sections over the windows moving out of whack at a different rate than the strips below the window.

The challenge then becomes, when the next full-length strip is hung, joining the strips over the window with those under the window … getting the pattern to line up and the strip to lie flat on the wall without torquing out of shape.

In this case, the pattern lined up pretty well. But strips under the window ended up being wider than those over the top. So there was a 1/2″ overlap, which would mess up the pattern match. This 1/2″ also caused the full-length strip to warp and develop a wrinkle.

This was an easy pattern and placement for dealing with such issues. All I had to do was cut along one of the palm tree stems, slide the strip up so the palm leaf pattern lined up, straighten out the full-length strip and work out the warp, and overlap that 1/2″.

All that sounds simple. But the truth is, I probably spent the better part of an hour getting it all to work out.

Paint Pulling Off Wall Where Tape Was Removed – Surface Stability Test

May 12, 2021
Paint pulling off wall where tape was removed.
Paint pulling off wall when painters tape was removed.
Paint pulled off wall and stuck to back of tape that was pulled off wall on new construction site.

It’s important to have a stable surface under wallpaper.

That’s because, when wallpaper gets wet with paste, absorbs moisture from the paste, and it expands. Then, as it dries, it lets go of the moisture and shrinks. When wallpaper dries and shrinks, it puts tension / torque on the walls.

If the surface under the wallpaper is not stable, the tension of the drying wallpaper can cause the underlying surface to pull away.

This photo is not showing the wallpaper pulling away from the wall. What is happening (usually) is that the paint (or whatever has been applied to the wall), has actually delaminated (come apart) from the wall.

This results in a “curled” seam, or a “popped” seam.

One way to test for this is to apply a strip of tape (blue painters tape, tan masking tape, clear Scotch tape, or other), let it sit a few minutes, and then yank it off. If the tape takes any paint along with it, you have a potential problem of the wallpaper not adhering correctly.

This is why it’s important to:

1, Before applying any coating, you must remove all dust from the wall, using a damp sponge, which must be rinsed frequently

2, Before hanging paper, a primer formulated specifically for wallpaper should be applied / rolled on and cut in to edges

A wallpaper-specific primer is designed to withstand the torque put on the wall as wallpaper dries. And it facilitates installation by allowing sufficient “slip” (maneuvering the paper) and “stick” (adhesion). The chemistry behind all this is fascinating – but too complicated to get into here.

If a wall is too “iffy,” and you don’t feel like the mess and expense of scraping off all the old paint, a liner can be applied before the actual wallpaper is hung.

A liner lessens the drying time of the wallpaper, which reduces the time there will be stress on the wall. A liner also redistributes stress on the wall, so much less chance of having seems detach from the wall.

A liner also adds additional cost to the job – for both material and labor, which may include an additional day(s).

Big Pink Flowers for New Baby Girl

August 7, 2019

Here is a nursery accent wall, getting ready for a baby girl in a few months.

I like Spoonflower’s paper, and it’s been a while since I’ve hung it, so today was fun.

Spoonflower is different from other papers. For starters, it comes in strips of certain lengths, so you have to figure out how many strips of each length you need. For an accent wall like this, that was easy – but it can get complicated in chopped up rooms like bathrooms. Each strip comes packaged separately, in it’s own long, skinny zip-top bag.

The paper is pre-pasted, which you don’t see much these days. I find this type much faster to hang. The paper is also designed to be overlapped at the seams (instead of butted). This means you will see a 1/2″ wide ridge from floor to ceiling down either side of each strip. (See third photo.) In the grand scheme of things, this is not very noticeable. (In the old days, all papers were hung this way, and I have some authentic 1940’s paper in my home office to prove it. 🙂 )

The material is thin paper, and it gets very wet when it is pasted, and it expands. When the paper dries, it shrinks a tad. If the seams were butted, you would end up with gaps between the strips. By overlapping the strips a tad, gaps are prevented. This method also puts less tension on the wall, so you have less chance of layers inside the wall delaminating. (Do a search here for more info.)

The composition and the thinness of the paper also make it difficult to cut, because it wants to tear. So you have to keep a supply of sharp, new blades handy.

This paper is very similar to one I blogged about on December 25, 2018. I’m betting it’s made by the same manufacturer, but sold under different brand names.

Note that Spoonflower also offers a peel & stick so-called “removable” option – do NOT go with this one – horrible stuff, that P&S.

This home is in the Heights / Timber Grove area of Houston.

Brunschwig & Fils’s Bibliotheque in a Heights Library

July 14, 2019


Another installer hung the paper in the first photo. For some unknown reason, two half-walls were left unpapered. I was called in to finish those two areas.

Brunschwig & Fils is a French manufacturer, with a long history. Like many higher-end brands, this product came with a selvedge edge that I had to trim off by hand (see last photo), using a razor blade and a 6′ long straight edge (not shown).

And, like many higher-end brand papers that are printed with ink that smells like mothballs, once paste is applied to the back of the paper, the inked surface absorbs moisture from the paste differently from the back side. When the top inked layer expands at a different rate from the substrate, you get waffling, or quilting. Sorry, no photo, but you can do a Search here to see previous blogs on this topic. Essentially, it’s a wrinkly mess.

One way to deal with this is to even out the moisture differential by lightly sponging water onto the face (inked side) of the wallpaper. The front can then absorb moisture from the sponging at the same time that the substrate is absorbing moisture from the paste.

As I worked with the paper, I discovered that it wanted to dry out quickly. So it helped a lot to also use a sponge to get a little moisture onto the back side of the wallpaper strip, before pasting.

Other tricks to slow drying out are to 1.) Book the paper (fold pasted side to pasted side and then roll up loosely like a newspaper) and then dunk the ends into a bucket of clean water. 2.) Place the booked strip into a black trash bag, which will prevent evaporation during the time the paper books. 3.) When the wait time is up, gently unbook the paper and lightly spritz the back with clean water from a spray bottle. Alternately, you could sponge the surface once again. The idea is to introduce a little more moisture, to loosen up the paste and to make the paper more malleable.

I had been told that this paper was difficult to work with, and that the seams wanted to curl. I had the opposite experience – I thought it was lovely to work with. The seams laid nice and flat, and the paper was easy to manipulate, and it clung tightly to the wall. Applying moisture to the surface and back got rid of the waffling, and any that did remain (there were small puckers in the white horizontal “shelf board” areas) disappeared as the wallpaper dried.

This home is in the Houston Heights neighborhood, and the interior designer is Stacie Cokinos, of Cokinos Design.

Humidity in Bathrooms – Not Good for Lower-End Solid Vinyl Wallpapers

June 7, 2019

People often think that vinyl wallpaper will be good in a bathroom, because water will roll off it. but in reality, very little water gets splashed on the walls – but a lot of moisture can get wicked into the seams.

These photos (you may want to scroll to enlarge them) show how the lower-end, paper-backed, solid-vinyl wallpapers tend to perform poorly in humid rooms like bathrooms. The problem is that moisture gets in between the seams and into the paper backing. That backing absorbs moisture and expands, curling away from the wall. The backing can actually go a step further and delaminate from the top vinyl layer.

This type of paper often performs like this when you’ve got people taking steamy showers, forgetting to turn on the vent fan, forgetting to keep the door open for air circulation, etc. Neither of these situations can be fixed. You will be stuck with these slightly curled seams.

The thing is, there are plenty of nice, paper or non-woven wallpapers out there, that will hold up a lot better in bathrooms.