Posts Tagged ‘expansion’

Grasscloth Engineering and Logistics – Technical Details Post

August 21, 2022
Grasscloth is a natural material that cannot be matched from strip to strip, so all the seams will be visible . In addition, there is usually a slight but noticeable color difference between strips / panels (called shading or paneling ) . So it’s important to plot the layout of the strips to give the most visually pleasing overall look. Usually this means balancing the width of strips so they are all equal , at least on the same wall . We call this engineering .
This wall presented particular challenges , due to the widths of the elements. Grasscloth comes 36″ wide . You can use your straightedge and a sharp razor blade and trim it down to any width you want.
The width of both the large wall spaces to the right and left of the bank of windows was 34.” The width of each window was about 35.” The width of the two spaces in between the windows was 7.”
So you’d think I could trim my panels on either side of the windows, and then over the windows, to about 34″-36″ – give or take a few inches (or fractions thereof).
But that would leave me with two 7″ wide strips between these 35″ panels. Although the look would be uniform and mirror-image from the center outward, moving from right to left you’d have: 35,” 35″, 7,” 35,” 7,” 35,” 35,” … those 7″ breaks were just not going to look right.
One option was to determine the width of the wall (189″) and make each strip an equal width. This worked out to six strips, each at 31.5″ Not good, because this would mean a seam down either far side. And since those sides were 34″ wide, that would mean a 31.5″ wide strip and a strip 2.5″ wide. Not attractive at all, and it would use up an extra strip of wallpaper.
This six strips @ 31.5″ wide scenario might also land with a seam smack in the middle of those 7″ wide interludes in between the windows. Not attractive at all.
So I decided to make the two outer strips 35″ wide. That left 119″ of wall space above the windows to be covered with wallpaper. Do some math and you get four panels of 29.75″ wide. This gave a balanced and uniform look to the area over the windows, and also prevented seams from landing between the windows.
Moving right to left, I cut and hung the full length outer strip first. Then I cut and hung the strip over the window on the right. Then I measured to find the centerpoint of the window in the middle. Turns out it was a bit less than 29.75″ away. So I trimmed that next over-window strip accordingly.
Once that was in place, I measured from that center point above the middle window out to where my left full-height panel would fall, 35″ out from the wall. Took the resulting measurement and divided by 2. Lo and behold, each of the next two panels over the window was going to be a bit wider than 30.” No problem. No one (but a paperhanger or maybe an engineer) is going to notice a 1/4″ or even a full 1″ difference in widths between this strips over the windows.
Another thing to point out … it’s important that I took measurements before cutting these strips for this second left-hand section. Because, since grasscloth comes at 36″ (and walls can be wonky), if my strips had been narrower (say, 28″), that last full-height panel on the left might have ended up needing to be 37″ wide – and that wouldn’t work because it only comes 36″ wide – plus you need at least 1/8″ to wrap around the corner.
Luckily I had the flexibility to be able to trim the panels over the windows to any width needed, to accommodate all this.
If you’ve followed all this so far, let me also toss in that we also need to figure how to get paper in between those windows. More on that below.
In this scenario, I’m moving from right to left.
Area beneath the windows needs to be treated in the same way, and preferably with widths that match what’s going on above the windows. In addition, it’s tricky because after you move across 12′ of wall space, the strips above and below the windows are going to twist and torque out of shape, so that last full-length panel on the far left might not butt up perfectly with the last strip under the windows.
The grasscloth is black , and my wallpaper primer is white . It’s common for teeny gaps to appear at the seams . In this case, it’s likely that white wall would peek out from those gaps. So I like to stripe under where the seams will fall with dark (diluted) paint . This takes measuring , plotting , and also a heat gun to get the paint to dry before the wallpaper hits it, to avoid staining. You can do a Search here to read more about this technique .
Now let’s talk about getting wallpaper in between those windows.
As you can see in the photo, if I hang a 30″ wide strip, a whole lot of paper is going to be cut off and thrown away. Also, a whole lot of sticky, pasted paper is going to bump against that window molding and maybe even the window glass. A lot to clean up! And unwieldy, to boot.
My solution was to stop the wallpaper just a little below the tops of the windows. Then I would patch in a 7″ wide strip in between the windows. This is trickier than it sounds, because, if it were a paper wallpaper, I could simply cut along a design motif and overlay the 7″ wide piece. But grasscloth is thick and overlaps don’t look good. Also grass has no design elements , and the reeds of grass don’t necessarily fall perfectly horizontal , and even if you cut everything perfectly true to square , if the window molding is a teeny bit off-plumb , then your edges won’t butt up perfectly.
So that’s a good reason for striping the black paint under where the butt join will occur.
Same thing for the sections under the windows. I measured and positioned the strips so that the top edge (which I had trimmed to be perfectly horizontal) fell between the narrowest part of the windowsill molding, for less visibility.
I admit, instead of butting the two pieces, here I did overlap the 7″ wide strip about 1/4″ onto the piece under the window, right at that narrow junction. It’s only about 3″ wide, and I figured no one is going to be examining it that closely, anyway. This saved me about a half an hour of measuring, trimming, testing, repeat, repeat.
This is my second window interlude, and by this time I had realized that it’s hard to trim stiff grasscloth around intricate moldings precisely . So I used paint to fill in the edges around the window molding, just in case there might be any gaps between the grasscloth and the molding, so you would see black instead of the white molding paint. I did this with a small sponge; if I had used an artist’s brush it would have been a bit neater and tighter to the conforms of the molding. But sometimes you’ve gotta relax and realize that no one’s going to be scrutinizing the insides of moldings below shin-level.
Area over windows finished, with drapes back in place.
Turns out this particular grasscloth is so uniform in color (quite unusual, I will add), that you can’t really see the panels , nor their equal widths , anyway. I’m still glad I took the time to do all this math and trimming.
Area below the windows, done. That last seam on the left bears some explanation, too. Moving across the top of the windows, I measured that that last strip – the full-length strip – would need to be exactly 35″ wide. It butted up nicely to the last strip above the windows.
But, due to twisting , shifting , expansion , unlevel and unplumb walls and ceilings , and other factors, there is a really good chance that that last 35″ wide strip would not butt up perfectly with the last 30″ wide strip under the window . So I planned to splice these last two strips together.
Yeah, the drapes are hanging there, I coulda overlapped the two strips about 1/2″ and the drapes would have covered it. With a thin wallpaper, I probably would have done this. But grasscloth is thick, and an overlap would be visible , and also the adhesive / paste can’t be trusted to adhere as well to grass as it would to paper .
So I plotted for a splice. Instead of trimming my last strip under the window to 30″ (read above), I trimmed it to 32″ wide. That way, when I hung the last full-length strip to the left, which was 35″ wide, it overlapped the piece under the window by a few inches. Then I did a double cut and spliced the two pieces. See below for details about that technique.
Grasscloth is 36″ wide, and this wall area is wider than that. So two strips were needed. This means you’re going to have a seam, and since grasscloth seams are always visible, it looks best to plot to have the seam fall down the center. It uses more wallpaper to do this, but it looks much better than having, for example, a 36″ wide strip next to an 8″ wide strip.
As mentioned above, in case you get thin gaps at the seams, a dark stripe of diluted craft paint under where the seam will fall, will prevent white wall from showing through.
Rounded / bull-nosed edges and corners have been popular in new construction for at least 10 years. I wish they’d go away. They’re very difficult to trim around, and hard for the paper to conform to and adhere to.
It’s very hard to trim around that rounded edge, because the paper is hanging over and blocking your view, because grasscloth is thick and stiff and your fingers can’t feel through it, and because the edges aren’t necessarily true and plumb so a laser level or other level won’t help you much.
I use this little gadget as a trim guide. It’s actually a small section of the same corner bead material that drywallers use when they assemble these walls. Cut to about 1″ long and notched in different places where you might trim along the edge of the wall.
It’s intended that you place your trimming knife in one of the notches and slide the gizmo along the edge and make your cut. I find that awkward and also inaccurate. So I prefer to use the notches as a guide and mark where I plan to trim with a pencil. Since this wallpaper is black, I used this marking pencil from my home sewing kit instead. Chalk might work, but I was afraid it might now wipe off completely.
The pink pencil line was barely visible, but it was enough for me to use a scissors to trim along the grasscloth. I like this better than using a razor blade as I can see better, and also less chance of scoring into the primer or wall. Which raises its own set of issues – do a search here to find previous posts.
Inside view of the trim guide.
Finished arch. Note the four panels of equal width above the arch. And two flanking full-height panels also the same widths.
I was lucky that there was no pattern to match, so I was able to butt my two flanking strips right up to the edge of the bull-nosed corner. No trimming needed! Then I measured the remaining width between these two strips (the area over the arch), divided by four, and cut four strips of equal widths.
I hung the two on the left, and then one on the far right. This left one strip still to be positioned to the right of center. So the pieces are going to meet over the arch, rather than the last strip falling in a corner.
Same as the last strip under the window (discussed above), it’s really difficult to get your last piece to fit in here perfectly. I’ve done it, but it takes a lot of measuring, trimming, testing, retrimming, and often starting all over again.
So I did a double-cut / splice.
A double cut involves cutting each strip an inch or so wider than it should be, and overlapping the two. Then you take a straight edge and sharp razor blade and cut through both layers. This handy tool is a wonderful non-slip guide for this process. It was invented by an installer colleague in the Wallcovering Installers Association ( WIA ) and she has them fabricated in various lengths (along with other cool tools ) and sells them on-line. Contact me if you’re interested.
Anyway, it takes a lot of strength to cut through two layers of grasscloth, so somewhat difficult for lil’ ol’ me.
You also want to be sure to not cut / score into the wall, because the tension of drying wallpaper can tug at the wall and cause it to actually come apart, leaving an open seam that’s difficult to repair.
So you’ve got to put some padding under the wall where the cut will take place. I use special strips of polystyrene (hard but flexible plastic) to pad the wall. Also invented by a colleague in the WIA , who also sells other cool tools and supplies. Contact me if you’re interested.
This black grasscloth was printed on a white substrate. If the seams aren’t absolutely tight, there can be worries about the backing showing through to the front. So sometimes we’ll take a piece of chalk or pastel (never oil pastel or permanent markers because they bleed and stain ) and run it along the edge of the paper – from the back, and taking care to not get chalk on the surface.
I do this frequently with dark papers ( do a search here to see previous posts ) but opted not to do it with this grasscloth. It wasn’t necessary, and might have stained the porous reeds of the grass. It was beneficial, though, to have striped dark paint on the wall under the seams, as mentioned above.
Ugh. Grasscloth comes 36″ wide, and this section of wall is 38″ wide. It’s not visually pleasing, nor is it easy from an installation point of view, to have a 36″ wide strip next to a 2″ wide strip. Or to use scraps and put a 25″ wide strip next to a 13″ wide strip.
So best to plan two strips of equal widths. Two strips, each 19″ wide, with the seam down the middle.
Actually, the strip on the left was 19″ wide, but I trimmed the strip on the right to 21″, because I like the wallpaper to extend 2″ over the top of the door molding. This provides a more stable surface in case of shifting foundation or walls, and less likelihood (knock on wood) of the seam opening up should the house / drywall experience shifting.
Note that design “rules” caution against seams down the middle of spaces. But it would have been more visually distracting (and used up more paper) to have made three strips of each 12.75″ wide. And would have looked even dumber to have used scraps left from other walls and put together two strips of disparate widths.
So the homeowner and I discussed during our initial consultation , and she was happy with the center seam. Once it was all finished, this particular grasscloth was so even in tone that you barely see the seams, anyway. Win-win!
This did use up additional paper, though, as noted in a previous photo above.

Solid Vinyl Wallpaper = Not a Good Choice in Humid Rooms

February 4, 2022

I hung this wallpaper 30+ years ago in a 2-room bathroom. In the sink room, the paper held up beautifully. In the toilet / tub room, over the shower and in a few areas up high (where humidity collects), some seams had curled back.

What’s the difference? Two main things – composition and humidity.

In the sink room, the wallpaper was a solid vinyl. But the backing was a thin paper, or possibly a thin non-woven (part synthetic) material. In the tub room, the backing was a gritty yellowish manilla type material.

This stuff is thick, and it will continue to wick up humidity through the seams, and that leads to expansion and then shrinking as the moisture dries. Over time, that will cause the paper to curl back on itself. Sometimes, the vinyl surface actually delaminates and separates from the paper backing. In this case, both backing and surface have curled away from the wall.

I really dislike these low-end papers, and encourage clients to not purchase them. Especially not for wet areas in bathrooms. In addition to the potential to curl up, the seams never look good.

Luckily, there are plenty of viable alternatives. Wallpapers with a paper backing, or a non-woven , will hold up much better.

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.

1″ X 5′ = 9 sq ft of Lost Paper

July 18, 2021

For all the prospective clients who think they can pull out their calculator and slide rule and then meticulously calculate that they can cover their walls with 186.7 sq ft of wallpaper – WRONG!

Here is a good example of waste, and why you can’t purchase wallpaper based on square feet alone.

Here we are working with a non-woven material that is packaged in 21″ wide x 33′ long.

In the photo, that narrow 1″ wide strip of wall on the left needs to be covered with wallpaper.

That’s 1″ wide x 5′ tall. That comes out to .41 square feet of wallpaper.

Sounds negligible, doesn’t it? But in real life, a whole lot more wallpaper will be called into play – and tossed into the trash – in order to cover this miniscule space.

Although I stockpile all scraps, there is nothing in my remnant pile that is long enough, nor the correct pattern match, to cover this space.

So I must cut a new length from a bolt of wallpaper.

The pattern has a 25″ repeat, so I had to cut off almost this much in order to come up with the correct pattern match. That’s 25″ long x 21″ wide … so already, we are nearly 4 square feet cut off and thrown onto the trash pile.

Now that I have the pattern matched correctly, I need 5 running feet of it to cover the length of wall in the photo. That’s 60″ long x the 21″ wide width of the wallpaper. That calculates to 8.75 square feet of paper.

Of those 8.75 square feet, remember that I need only a 1″ wide strip. As previously mentioned, that comes to .41 square feet.

So, 8.75 sq ft – .41 sq ft = 8.33 sq ft of paper that can’t be used anywhere else, and will be tossed onto the discard pile.

That’s 8.33 sq ft of waste. Considering that the average single roll of wallpaper contains 28 square feet (but in reality, only 22 square feet of useable paper), this leaves you with only 19.75 square feet of useable paper.

In double roll speak, this means a bolt with 56 square feet, which is better calculated at 44 useable square feet, after hanging this one puny 1″ wide strip, you are left with 47.7 sq ft of useable paper – nearly 10 sq ft lost for just one 1″ wide strip!

And this is just the tip of the iceberg. I haven’t even gotten into pattern repeats, trimming at ceiling and floor, going around windows, vaulted ceilings, stairs, multiple drops, expansion when wet with paste, and all sorts of other factors.

Bottom Line: We paperhangers know the ins and outs of this stuff.

And homeowners don’t. Nor do contractors, painters, handymen, nor even engineers. Most of all, NOT engineers. (I love ’em all,,,, but they tend to get bogged down in details, and overlook the grand scale.)

Bottom, Bottom Line: Let the paperhanger measure the space and calculate how much wallpaper to order.

Cloud Mural in Baby Girl’s Nursery

May 8, 2020


Want a room that will suit a child of either gender, and also grow with him/her into the teen years? This “Nuage” cloud mural by Anewall (A New Wall) checks off all the boxes!

This mural was not custom-sized, but came in pre-set dimensions. The product came in six strips, and the overall size was a bit taller and wider than the wall. In the third photo, I am laying out all the strips on the floor. This is very important, because you want to be sure you are grabbing strips in the correct order before you paste them to the wall.

Also, laying out the mural on the floor enabled me to see the whole design, so I could decide how much of the excess to cut off at the top and bottom. And I could also determine where the center was (break in the clouds), so I could position it where the parents would be placing the baby’s crib against the wall.

The material was pre-pasted, so I didn’t need to lug in my big table and pasting equipment. The paste is already on the back of the paper, and is activated by water. Some people spray the back with a squirt bottle. But I find this messy and sporadic. I prefer the old-fashioned water tray method. It’s quick, easy, and gives the most uniform water coverage.

In the fourth photo, you see my plastic dropcloth protecting the floor, two towels on top of that to absorb water splashes, and then my green water tray. Each rolled-up strip will be placed in the tray, and then unrolled and pulled out on top of the towels. This exposes the paste to water, which activates it. Then each strip is folded pasted-side-to-pasted-side (booked), and set aside to absorb the water/activate the paste/expand/relax.

In the next shot, I have aimed the red line of my laser level along the center of the wall. I am hanging my first strip, butted up against the red line. On we go, until the wall is covered with clouds!

In the close-up, you see that the design has a sort of tufted “quilty” look to it.

HOWEVER, I did experience some excessive vertical expansion / stretching between some of the strips. This means that some strips became wet with water and expanded more than others. And that means that the pattern on some strips did not match up perfectly with the previous strip. The protocol is that you match the pattern at eye-level, and then as the paper moves up and down the wall, the pattern will fall out of match.

The good thing is that this pattern is so scratchy and “quilty” that the eye will never notice a 1/8″ or even 1/4″ mis-match, especially not from a distance. With a more precise and visible pattern, this would be an issue.

This home is relatively new, and is in the Woodland Heights neighborhood of Houston.

Bibliotheque Install Details, Pt III – Curling Edges

March 18, 2020

As mentioned in a previous post about this install, wallpaper paste introduces moisture to the back of the paper, which causes the backing to absorb moisture and expand – and, sometimes, as in this case, the expansion will cause the paper to curl back on itself.

As you can imagine, this makes it a whole lot harder to get the strip positioned and secured to the wall.

Poppy Dotty Pantry

December 14, 2019


You can get away with a lot of avant garde-ness in small areas. This home in the Kingwood community of northeast Houston is mostly traditional in floor plan and d├ęcor. Yet the homeowner has found a few places to inject a little playful personality.

One is the backs of these cabinets in a butler’s pantry (but they are using it as a bar).

The lightly textured, indistinct smeary dots spread in a diamond pattern are nothing short of fun!

What’s especially clever is that the homeowner found a colorway that coordinates with not just the wall paint and furnishings in the home, but also with the weathered chandelier in the adjoining dining room, the nubby rug, and other furniture.

These are the little details that “pull a look together” – and this homeowner did it all on her own, acting as her own interior designer!

This wallpaper pattern is by A Street Prints, which is by Brewster. It is a non-woven material that has a high fiberglass content which prevents expansion and shrinking, and makes removal at a later date easier. I hung it using the paste-the-wall method.

Dark Papers – Visible Seams

September 10, 2019


Wallpaper is paper, and when paste is applied to the back, the paper gets wet and expands a little. When it hits the wall, it dries – and often that means it will shrink, even if just a tad. That will leave minute gaps at the seams. If the paper is dark and the wall or the substrate are light , you will most likely see white gaps at the seams.

Some manufacturers combat this by printing dark patterns on a darker substrate. This is what you see in the photo above. But it also helps to color the edges of the wallpaper with a corresponding color of chalk. (You can’t use ink, because ink will bleed and discolor the wallpaper.)

Sometimes you can go back and color in the seams with hobby paint or chalk, which sounds simple but actually takes some technique and finesse, to color the areas adequately and avoid staining the paper.

Painting the wall the color of the paper is a thought, but not as feasible as it sounds, because wallpaper wants to stick to wallpaper primer, not paint. And I’ve seen paint lift off the wall when the wallpaper dried and put tension on it – so, not using that trick again.

Paint with a clear wallpaper primer over it is another idea – but it adds an extra day (or two) and more labor and material costs.

What I did in this case, was to try different pasting methods. This wallpaper, from the Historic Homes Collection by Thibaut, is pre-pasted and engineered to be run through a water tray to activate the paste on the back of the paper.

This method works super with most of their colors. But, because the water tray adds a lot of moisture to the wallpaper, the amount of expansion and then shrinkage results in tiny gaps at the seams – not a big deal with a white or light-colored wallpaper. But with this black paper, it was showing too much white at the seams. Yes, a 1/64th” is too much, when you are looking at white between black.

So instead of running the paper through the water tray, I experimented with pasting the back of the paper. I knew this method would allow the paper to expand less, dry faster, and shrink minimally.

But wallpaper that has a thin layer of pre-paste on the back does not respond well to the installer applying paste to the back on top of the pre-paste. You are greeted with a thick, dry, gummy mess that is hard to manipulate on the wall.

There were also a lot of bubbles and blisters under the surface. Yes, you can be assured that these will disappear as the paper dries – but it sure makes you nervous while you are looking at them!

Spraying the back of the paper with water from a mister didn’t work, either, because the spray bottle spread water unevenly, water sloshed onto my work table, and there was nothing to enhance the “stickiness” of the manufacturer’s pre-paste.

After experimenting, what worked best was to apply paste to the back, full strength, and then quickly spritz the back with water and roll it around, to thin down the paste I had just applied, and to add enough moisture to activate the pre-paste.

The wallpaper strips with this pasting concoction were thick and muddy and difficult to maneuver, but the drier paste did lock down at the seams more quickly. I didn’t have issues with shrinking or gapping seams after I started using this pasting method.

Low End Wallpaper – Not So Bad This Time

October 12, 2018


I’ve said it before – these budget-friendly, pre-pasted, manila paper-baked solid vinyl wallpaper products are generally not good quality, and the Norwall brand is about at the bottom of the list. In fact, I often will decline to hang it. Do a Search here on those terms, or click the Page to the right “Stay Away From … ” for more info.

However, this homeowner, a Meyerland neighborhood (Houston) victim of the Hurricane Harvey flooding, and a client for whom I had worked back in the ’90’s, really loved the pattern, as well as the price-point. And she wanted her entry to look as it had before the flood ravaged her home.

I was pleasantly surprised. The paper went up OK, and the seams looked fine. It’s possible that the company has improved its product. But it’s more likely that my new installation method helped.

Instead of following the manufacturer’s instructions to run the paper through a water tray, which makes the material too wet and promotes bubbling, and instead of pasting the back of the paper, which turns it into a gummy mess, I tried something new. I used a spray bottle to lightly spritz fresh water onto the back; this activated the paste, but was not so much water that it would cause bubbling or seam curling or over-expansion of the material. I booked the paper and put it in a black trash bag to sit a few minutes.

Next I rolled paste onto the wall. I started out using a very faint coat, but found that a tad more worked better. I used a brush to cut the paste into the edges and around the floor and ceiling.

When I took the very slightly dampened paper to the wall and smoothed it against the lightly pasted surface, it adhered very nicely. It was pretty easy to smooth into position, although there was some twisting of some strips, which could have been a problem in a room that required more strips next to one another.

Usually these inexpensive vinyl papers grow bubbles, because, as they dry, there is nowhere for the moisture to go (because it can’t pass through the vinyl surface), so blisters form. But today was very little bubbling.

Best of all, the seams looked good. I didn’t get any of the raised edges that are so unattractive, and that allow moisture / humidity to penetrate and cause the backing to swell and pull away from the wall.

I am not saying that I was happy with this paper. But it was a lot better than I expected. And I hope that it will continue to look good for years to come.