Posts Tagged ‘skim-coat’

Stuff Doesn’t Wanna Stick To Slick

March 23, 2022
Tomorrow this breakfast area wall will get wallpaper. Today is prep day.
The wall has a very heavy texture, plus some issues with previous patches in areas, probably due to drywall cracks. I need to skim-float over all this to smooth the surface.
In addition, the current paint is quite glossy – and this can present a problem for the smoothing compound to adhere to it properly.
So I want to prime over this gloss paint before I skim-coat the walls. The primer has to both stick to the gloss paint and provide a base that the smoothing compound will adhere to.
Another issue is that I won’t be using this every day, so keeping it shaken up and useable was a consideration. I looked high and low for an appropriate primer. Finally I snapped that the Roman Ultra Prime Pro 977 that I use under my wallpaper jobs checks off all the boxes … It sticks to just about anything, and it dries nice and flat / matt so any topcoat (wallpaper or smoothing compound) can grab ahold and stick, I have it in my van all the time, and I use it frequently enough that it’s always mixed up and ready to use. To top it all off, it dries in less than an hour. Voilà!
This stuff can be tricky to find. Sherwin-Williams used to stock it for me, but became unreliable. Now Murphy Brothers on Bissonnet (Houston) gets it just for me.
Besides dropcloths on the floor, here I’ve tacked strips of thin paper dropcloth material along the wainscoting (I also do this along baseboards) to keep any drops or roller splatters from marring the homeowners’ floor and moldings.
Here it is applied. Since my goal is to cover and eliminate the glossy paint, and then provide a base for the smoothing compound, this coat doesn’t need to be opaque or cover the wall evenly.
Tomorrow we’ll see how the wallpaper turns out!
Fast-forward … I’ve floated the wall and sanded it smooth. Compare the smoothness to the “before” picture at the top.

Kill Point Over Door, Ridge, More

February 25, 2022
After you’ve hung wallpaper on all the walls in a room, the point where your last strip meets up with the first strip is called the kill point . This virtually always ends up in a pattern mis-match. That’s why you engineer to place it in an inconspicuous place, such as behind a door.
This powder room, though, had no hidden corner or handy door. That meant that I would have a pattern mis-match a full 5′ high, to the left of the toilet you see here. I prefer to have the pattern match in a corner like this. As you can see – it does. I will explain how I accomplished that.
I decided to place the kill point over the door. Even though this space is 2′ high and a mis-match might be noticeable, not many people are looking up over the door, so it’s a better choice than in a 5′ or 9′ long corner.
The dark smudges on the wall in the photo are where I’ve spread paint, to prevent white walls from peeking out, should the dark wallpaper shrink as the paste dries.
Here I’ve positioned the strip on the left. This leaves a gap of about 3″. Once I match the new strip up to the piece on the right, its pattern will not match perfectly with the strip on the left.
Now I’ve positioned both strips, and the one on the right is overlapping the one on the left.
Here’s an idea of what the pattern mis-match will look like. To be honest, it’s not all that bad, with this busy pattern and being up over the door. Still, I thought I could make it look better.
I’m going to do a double cut , which is our installers’ fancy term for a splice. I’m going to cut through the two strips, splicing them together, cutting along the vertical foliage elements, to minimize cut-off motifs and to disguise the splice.
When double cutting on the wall, it’s really important that you slice through the two layers of wallpaper only , and not cut into the primer or wall surface beneath. This is because, if the wall surface becomes scored or compromised, when the wallpaper paste dries and the paper shrinks and pulls taught, it can put tension on the wall surface. If the surface is not intact, it can give way and actually come apart ( delaminate ), resulting in wallpaper that comes away from the wall – and there’s nothing beneath it to paste it back to.
I’ve blogged about this before, so do a Search here to learn more. It’s important!
Anyway, to protect the wall beneath where I will make my splice cut, I’ve placed three layers of scrap wallpaper, to pad the wall. I figure I can cut through the two top layers, but not all five.
Note that three layers of non-woven material have some thickness, and can “throw off” the splice cut and prevent the top two strips from fitting together perfectly. In this case, the paper is flexible enough that I’m not worried about that particular scenario.
The strips are in place, and I’m ready to make my cut. I prefer to use a single-edged razor blade held in my fingers, rather than a blade-holder. What’s most important is that the blade be brand new and spankin’ sharp!
Here I’ve made my cut and am removing excess paper from the right side of the top strip. Look carefully and you can see how my razor blade followed the contours of the vertical foliage design elements.
Here I’ve removed the excess paper from the left edge of the bottom strip. You can see they are poised to fit together nicely.
Before fitting the two strips back together, though, I’m examining the wall surface. Check the photo carefully, and you’ll see that I did, after all, score into the primer. 😦 The surface below is skim-coat that was used to smooth a textured wall – and another potential layer that may come apart when exposed to tension from the drying wallpaper.
Shoulda used a Boggess Strip. https://www.steveboggesspaperhanging.com/lexanpage.htm
One way to prevent the wall from delaminating is to put something over the compromised area, to distribute the tension of the drying paper and take it away from the cut wall. Here I’ve taken a scrap of wallpaper, which is a tough non-woven material, and carefully peeled the printed surface from the white substrate (no pic of that process). Now I have a thin material that I can use to pad the wall.
I’m using the black printed side facing out, in case the spliced strips shrink a little – anything peeping out will be black and not noticeable.
Here is the bit of paper in place, spanning across the cut on the wall.
Now I’ve smoothed the two top strips back into place. Since my double cut followed along the vertical foliage elements as much as possible, and because I cut around the gold flowers to keep them full and round, the pattern looks like it matches up just about perfectly.
But wait! … What’s that lump / ridge under the wallpaper, the full height of the seam? That’s my seam padding! Doesn’t look great.
I’m really surprised at this. The non-woven wallpaper material is thick. But that’s why I pulled the top and bottom layers apart, to make my patch piece thinner. I guess not thin enough. Once dried, this ridge is going to be obvious.
But, to be honest, this is up over a door where no one’s going to be spending much time looking. In addition, once I get my 100 watt light bulb out of there and replace the homeowners’ original, small light fixture, this bump under the wallpaper will be pretty much indiscernable.
Still, that lump was buggin’ me. Another invention from my colleague Steve Bogges to the rescue! Pictured is his seam tape , which was made specifically for this type situation. This is very thin – yet strong – paper tape that is used to bridge cut areas like this, and prevent tension from drying wallpaper from tugging at unstable walls.
The tape has a pre-pasted side (the gloss you see), and feathered edges, to make it less noticeable under wallpaper.
Hard to see, but here I’ve placed the seam tape over the cut wall areas
Now the two top strips have been smoothed back into place. Amazingly, no bump from the seam tape beneath shows. And the pattern mis-match is barely visible, too.
Win-win!
All that’s left to do is to wipe paste off the surface of the wallpaper. This overlapping and splicing does mean that wallpaper paste will get on the surface of the strip underneath. Actually, there is a way to prevent that, and it also involves products from Steve Boggess
But … that’s a blog post for another day …
This pattern is called Peonies and is by Rifle Paper.

Fixing Drywall Damage From Where Vanity Was Removed

January 20, 2022
The powder room in this 1990’s home in the Houston Heights is being updated, and that means replacing the wall-to-wall vanity. Here the vanity has been ripped out. The areas where the backsplash was adhered to the wall have pulled the top surface of the drywall off. In addition, the plumber had to cut out a section of drywall in order to gain access to the pipes, so he can install the new faucet and handles. You can see the connections roughed in.
You can’t hang wallpaper over this mess. First of all, it way too uneven – all those bumps will show under the new wallpaper. And the outline of the ” trapdoor ” will leave a big square ridge under the paper. Thankfully, the plumber secured the panel with drywall screws – most plumbers just leave you with a chunk of drywall floating in space, or even just an empty hole.
Back to patching issues … in addition, the torn areas of drywall will absorb moisture from the wallpaper primer and / or paste and expand, creating bubbles that will show under the new paper.
I needed to fill in dips and gouges, even out high areas, and prevent bubbling drywall.
Gardz by Zinsser to the rescue! This is a penetrating sealer that soaks into porous surfaces and then dries hard, binding them together and creating a stable surface, as well as resisting moisture from water-based top coatings.
This picture doesn’t look much different, but here the torn drywall is a little darker, indicating that the Gardz has soaked in and dried. The surface is now ready for a skim-coat.
But first, the trap door needs to be addressed. I covered the cut areas with four strips of self-adhesive mesh drywall tape (no photo).
Then I went over everything (wall to wall) with joint compound (commonly referred to as mud ) (no photo).
Because of the thickness of the high and low areas, this had to be a thick coat of smoothing compound, and would take a long time to dry. So I went to the jobsite two days ahead of our install date, to do these initial repairs.
And – no – you can’t use quick set or hot mud or 5 or 20 minute mud to do these repairs. These products are intended for repairs of small areas. Top coatings like primers, paint, and wallpaper paste do not stick well to them. Don’t let a contractor sweet-talk you into letting him use any of these to smooth a large area of wall.
Here is the wall after my first, heavy, coat of smoothing compound. I use Sheetrock brand’s Plus 3.
The bubbles you see just left of center show that Gardz didn’t 100% do its job of sealing out moisture, as a little expansion and blistering has occurred. Not a biggie. These will disappear when the surface is sanded. There is usually not a problem with these re-appearing.
When I got to work two days later, the smoothing compound had dried. I sanded pretty smooth. Then vacuumed up the dust on the floor, and then used a damp sponge to wipe residual dust off the wall. This is important, because no coating will stick to dust.
The wall still wasn’t perfectly smooth, so I did another skim-coat. This was much thinner, so didn’t need a lot of time to dry. I used a fan and my heat gun to speed things along.
Once that was dry, I sanded it smooth, vacuumed and then wiped off all dust. Then rolled on my favorite wallpaper primer Roman Pro 977 Ultra Prime. I have the paint store (Murphy Brothers in central Houston) add a little blue tint, so I can see it when I apply it to the wall.
What a transformation! Now this wall is ready for wallpaper!

Crumbly / Unstable Wall Issues

June 2, 2021
Starting to strip wallpaper. You see the top, inked layer, the tan backing layer, and the white skim-floated wall beneath.
Wall surfaces delaminating at seams
Gardz, a penetrating sealer that binds surfaces together and dries hard.
My first idea was to just Gardz the lifted areas. The sealer is newly applied and still wet in this photo.
Gardz’ing the whole wall created a more stable surface. This doesn’t look much different from the photo above. But in actuality, the the Gardz has sealed and “locked down” the surface, as well as soaked into the material and sealed the inner layers as well.
Applying a skim-coat to even out the surface levels.
Once this skim-coat is dry, it will be sanded smooth.

The installer of the original paper did a good job of skim-floating the wall and creating a smooth surface. But he didn’t apply a sealer or primer. Thus, when I used water to strip off the old wallpaper, the moisture soaked into his skim-coat (drywall joint compound, a plaster-like substance, which we also refer to as “mud”). Some of the skim-coat came away from the wall,,, particularly in areas of stress, such as where the wallpaper seams had lain.

In fact, long (years) before I began stripping the wallpaper, many of the seams had started to pull away from the wall, taking inner layers of the wall along with them. This is because wallpaper shrinks as it dries, and that creates tension on the wall. If the wall surface is unstable, these layers can delaminate (come apart), and the result is an open seam with chunks of wall material stuck to it.

This can also happen over time, as temperature and humidity changes can cause the wallpaper and / or wall surface to absorb and then let go of moisture. All this puts stress on those wallpaper seams and on the layers inside the wall.

Besides these seam areas that let go, I had one wall where the entire surface came apart in a mottled effect.

Another factor is that the original skim-coat had been applied over a glossy paint. It’s hard for anything to stick to gloss. The guy probably should have rolled on a “bonding primer” before applying his skim-coat.

Of course, all that increases the time and materials needed, and ups the cost to the homeowner.

Gardz is a wonderful product that is designed to soak into surfaces and “bind them together.” It dries hard and is pretty water-resistant. It was originally intended to “lock down” torn drywall. But workmen quickly discovered that it would fix a whole lot of other surfaces – such as my delaminating skim-coated walls.

At first I thought I would just Gardz (we use it as a noun and as a verb!) the areas that were lifting. Once it dried, I intended to skim-float over these areas, sand smooth, and then prime the entire room with my usual wallpaper primer – Roman Pro 977 Ultra Prime.

But I realized that, even after I wiped down the walls with a damp sponge, they were still covered with powder or grit. This was powder from the layer of skim-coat, as well as residue from wallpaper paste. Neither my primer not wallpaper will stick securely to powder.

So I decided to roll Gardz on to all the walls, ceiling to floor.

Fifth photo – I was really pleased with the way the Gardz soaked in and drew all those layers together. There was no more power on the surface, and the inner layers of the walls were all pulled together.

To even over these vacant areas, and to create a pristine new surface, I skim-floated over the entire wall surface – all walls, floor to ceiling. See last photo.

Once that is dry, tomorrow morning, I will sand everything smooth. Next I’ll apply my 977 primer.

Then walls will be stable, and the surface will be ready to take on the new wallpaper.

From Textured to Smooth Wall Surface

March 30, 2021

Many homes in Houston have textured walls. In new homes in the suburbs, the texture is often really heavy – the so-called “Tuscan” look.

The texture will look bad under the new paper, plus it interferes with good adhesion. So it needs to be smoothed out before the paper can go up.

I use the process called “skim-floating” or adding a “skim-coat.” You can Search here (upper right corner) to find posts explaining this process.

And don’t pay your painter or handyman to do it – they don’t understand what’s needed for wallpaper. I’m many times better! 🙂

Here are before and after pics of a powder room I smoothed and prepped in the Bellaire neighborhood.

That second photo is enlarged many times – the wall is actually much smoother than the picture makes it look.

Repairing Damage from Remodeling

March 5, 2021

I hung this paper in a little boy’s bedroom about two years ago. Now a new baby is coming, so Son #1 is moving from the nursery to his “Big Boy’s Room” next door. In the process of the shuffle, the parents had the connecting Hollywood bathroom updated, and this involved moving a door – which meant messing up the wallpaper.

As you can see in the top photo, instead of taking the time and effort to remove the wallpaper, the workmen put their patching compound right on top of it. I don’t like hanging paper on top of paper, for many reasons. There are adhesion issues. And also, for one thing, it’s not good to have seams fall on top of seams. For another, because the new paper is somewhat thick, you would have a visible ridge from top to bottom along the edge of the new strip.

So I took a razor knife and cut roughly around the workmens’ patch. Then I stripped off the paper around it, up to the edge of the adjoining strip. I did this on both sides of the corner.

This wallpaper is of a non-woven material, and is designed to strip off the wall easily and in one piece when it’s time to redecorate. I was pretty disappointed that that turned out to not be the case.

On the other hand, I was happy that it didn’t. Stripping paper that way puts a lot of stress on the wall surface, and you can end up with delamination (coming apart) of various layers under the paper (primer, skim-float, paint, drywall).

So I used a more labor-intensive, but lower-impact method. Click my page to the right for more info on the process. I first stripped off the top, inked layer of paper. That left the white backing still adhering to the wall. I used a sponge to apply plenty of water to this backing. The idea is to reactivate the paste that is holding it to the wall. Once that paste was wet enough, the backing pulled off the all cleanly and easily.

I was really pleased that my primer from the original install held up perfectly under all this soaking and tugging. I had worried that it might “rewet” and pull away from the wall, which had been my experience with it before. I had used Gardz, a penetrating product designed to seal torn drywall. It’s also good at sealing new skim-coated walls. And wallpaper sticks to it nicely, so all the better!

One photo shows you the stripped off area next to the edge of the remaining strip. You can see the thickness of this existing strip. The new wallpaper will butt up against this, and there will be no ridge because the thicknesses of both strips are the same.

Another photo shows my stripped-off area next to the contractor’s patched area. There is a difference in height between the newly revealed wall and the patched area – and that will show as a ridge or bump under the new wallpaper.

To eliminate that difference in height, I skim-floated over the area. In one photo, you can see the wet (grey) smoothing compound. I set up a strong floor fan to assist in drying. My heat gun also came in handy.

Once it was dry, I sanded it smooth. Now you don’t see any transition between the newly exposed wall and slightly higher patched area. I applied Gardz to the all the newly patched areas. Set up the fan again. And once it was dry, I put up the replacement paper.

It’s a good thing the family had paper left over from the original install. If they had had to purchase new paper, it could have come from a new Run (slight difference in color shade), and that would have meant stripping off and replacing three walls.

We had barely enough paper. The corner was out of plumb by as much as 1/2″ from floor to wainscoting, on each side of the corner. That adds up to an inch out of whack. That one inch meant we needed a whole new strip of wallpaper, to get the paper on the wall to the left to match up with that on the wall to the right.

Long story short, the whole thing turned out great. There is a bit of a mis-match in that corner, but it’s not very noticeable at all.

The wallpaper is by the Scandinavian company Boras Tapeter.

The home is in the West University neighborhood of Houston.

Mess Stripping Wallpaper

February 6, 2021

Over the years, this powder room ended up with at least four layers of wallpaper. Some had been stripped down to the backing layer before the next layer went up, sometimes a primer was used, and in other cases, the installer simply plopped the new paper on top of the old.

The homeowners attempted to remove the multiple layers of paper. This mess would have been difficult to begin with, but, to complicate things, unfortunately, they pulled some bad information off the Internet. You can see how the use of a “paper tiger” scoring tool caused damage to the wallpaper as well as to the surface underneath – and didn’t help at all to loosen the old wallpaper.

My solution was to peel off the top layer of vinyl paper – the brownish striped faux finished pattern in the upper left of the photo. Then I used a sponge and lots of water to soak the tan backing until the paste reactivated and the paper could be scraped off the wall.

I would have preferred to also take off the layers of paper that remained underneath. But time was a consideration, and also the likelihood of damage to the wall surface. And I wasn’t sure if there was drywall or plaster under there.

So I used the product Gardz to seal off the revealed wallpaper. (Do a Search here on the word ‘Gardz” to learn more about this ingenious product.) Once that was dry, I skim-floated over the entire surface, to create a new, plaster-like layer. That was allowed to dry overnight.

The next day, I sanded this skim-float layer smooth. Because the smoothing compound had to be applied thickly, this resulted in a massive amount of dust. Luckily, it was all contained in the powder room, and was easily vacuumed up.

Then I used a damp sponge to wipe residual dust off the wall. This was followed by another coat of Gardz – a product that soaks in, dries hard, and effectively seals the surface. It’s a good sealer for new skim-coat, and it also works nicely as a primer under wallpaper.

With fans blowing on it, it dries quickly, and I was able to start hanging paper in an hour or so.

Roiling Clouds Wallpaper in a Montrose Bathroom

July 4, 2019


Historic British manufacturer’s Fornasetti Line “Nuvolette” wallpaper pattern… I have long wanted to hang this paper, and finally got my chance today!

The walls in this first-floor bathroom of a newish contemporary styled home in the Montrose neighborhood of Houston were textured and covered with a semi-gloss paint. (top picture) It took me a day and a half to skim-coat the walls with smoothing compound, let dry, sand smooth, vacuum up the dust, wipe dust off the walls, prime, and let the primer dry. (second photo shows the smoothed and primed walls)

You would see this pattern better in a larger, less broken-up room, but here you can tell that it is a powerful depiction of roiling thunder clouds storming powerfully toward the west.

The product is unusual, in that it comes in a 2-pack set of “A” and “B” rolls. Each bolt is the same width and length as many Cole & Son papers. But the pattern is placed on those bolts very atypically, and the pattern match is equally unexpected.

Usually, wallpaper patterns match straight across from strip to strip. (straight across match) This means you see the same design element at the top of the wall on every strip. Or they drop down bit on every other strip, then pop back up to the top of the wall on the third strip. (drop match)

A much less common and much more complicated patter match is when the pattern motif repeats itself at the top of the wall only on every fourth (or more) strip. It can take a lot of mind-bending to figure out how to get the pattern placed correctly, and without wasting more paper than necessary.

Look at the upper left of the label, and it says that when placing the A strip to the right of the B strip, it’s a straight match. But when you position the B strip to the right of the A strip, it’s a drop match. This makes everything even wackier and more complicated!

What helped me here is that this home had plenty of room to roll out the bolts of paper, and plot out how the pattern would fall. (see photo) No one was home, so I had peace and quiet to concentrate and get my head around the intricacies of the pattern.

It turned out that the “straight match” indicated on the label was an error – no strips featured a straight match. Good thing I had all that floor space to roll the bolts out, so I could determine that.

Because the pattern match was so unpredictable, it was not possible to cut all of the “odd” and “even” strips ahead of time. And the very unlevel / unplumb qualities of the room also stepped in to make this impossible.

One thing that helped was that this was a non-woven material, which meant that the wallpaper did not need to be booked (left to sit and absorb paste and expand) before hanging. So as soon as I was able to figure out the pattern match for the upcoming strip, I was able to paste and hang the strip-in-hand.

If I had had to figure, measure, plot, paste, book, and then finally hang each strip individually, it would have taken a lot more than the eight hours it did take me to hang this 8-roll bathroom.

A big help on this pattern is that I belong to the Wallcovering Installers Association, and I check our Facebook page every day. (Sorry – it’s private … you can’t peek!) It was there that I learned about others’ experiences with this Nuvolette design, and how they tackled the pattern repeat and the install.

Getting Smoothing Compound To Dry

June 13, 2019


The walls in this powder room were textured. (see top photo) To ensure that the new wallpaper looks good, and that it has a solid surface to cling to, the walls need to be smoothed. This is called floating, or skim coating, and I do a lot of it here in Houston. To do that, I trowel on a plaster-like substance, let it dry, then sand it, vacuum up the dust, wipe residual dust off the walls with a damp sponge, and then prime.

What takes the most time is waiting for the smoothing compound (drywall joint compound, which we also call “mud”) to dry. If the texture is heavy, often it has to dry overnight. The downside of this is that it adds an extra day of labor and expense. But when the texture is lighter, the drying can be speeded along.

In the second photo, you see some of the ways I get mud to dry more quickly. On the counter* you see two box fans, and on the floor is a much stronger fan. On the counter is also a space heater. Hot air in the room absorbs moisture, sucking it out of the wet smoothing compound. I let the room heat up, and then I have to open the door and let the moist air out – over and over again.

The yellow objet on the floor is a heat gun. A heat gun acts like a hair dryer on steroids, and can get small stubborn areas to dry pretty quickly.

A few other things help speed drying … Walls coated with flat paint will dry more quickly than with glossy paint. And having the air conditioning and / or heat cranking away will help, because, while regulating the temperature, these climate-control systems also pull humidity out of the air. I also like to turn the HVAC system’s fan from “Auto” to “On,” so that air is circulating continuously, which also pulls humidity out of the air and helps the walls to dry.

*I normally keep a dropcloth on the vanity counter. But the vibrating fans can cause the dropcloths to slip, and you don’t want anything crashing down on the homeowner’s countertop. I do have lengths of self-grip shelf liner that help keep the fans from moving around too much.

Smoothing a Textured Wall

June 16, 2017

Digital Image

Digital Image

Digital Image


The bumps on textured walls (see top photo) will show under wallpaper and look horrible, and the texture also impedes good adhesion. So I “skim-coat” the walls with joint compound (“mud”), which is much like plaster, let dry, and then sand smooth (see middle photo).

The walls need to be sealed before wallpaper can go up, and for this, I like Gardz, a penetrating sealer that soaks into the surface, binds everything together, and dries hard. It’s also a wonderful primer to hanging wallpaper on.