Ensuring Smoothing Compound Will Adhere to Glossy Surface

This wall has a texture on it that will look bad under the new wallpaper, and it will also interfere with adhesion.  So the wall needs to be skim-coated / skim-floated to smooth it.  But the current paint on the wall is glossy, as you can see on the right side of the photo.  The smoothing compound is sticky stuff, but it (like many coatings) cannot be trusted to adhere to a shiny surface.  I say it’s like the toy Colorforms … the new material will kinda stick – but not really stick .
But if the surface is dull , or matt finish , the new coating will be able to grab ahold and adhere .
To make this wall surface dull , I’m rolling on a primer that will dry with a flat / matt finish . 

There are various primers out there that will adhere to a glossy surface and then dry flat.  But I’m using my trusty wallpaper primer , Roman Pro 977 Ultra Prime .  Yes, this is a wallpaper primer .  But it also checks all the boxes … it sticks to just about anything , it dries quickly, especially with a fan blowing on it, and it dries with a matt finish that wallpaper paste – and smoothing compound  – will adhere to.  At $70 or more per gallon , yes, this stuff is expensive .  But it works , it’s low odor ,  it’s already on my truck , and it saves having to carry around an assortment of of primers and materials.  

Here’s my smoothing compound.  Sheetrock brand Plus 3 joint compound used for working with drywall .  Note that quick-dry formulas , nor spackling compound , are not suitable and won’t hold up under wallpaper .  You can search here for my other posts to see more about the smoothing process for textured walls . 

Skim-Floating to Smooth a Textured Wall

Wallpaper is to go on the top 2/3 of the walls in this large dining room. But the walls are textured, and that texture will show through the new paper. Which looks pretty bad , IMO , especially since most the design is plain white background. So here I am applying a skim-coat by skim-coating / skim-floating the wall to smooth over the texture.

Close up. A lot of people use a wide broad knife or drywall taping tool . But I prefer the control I have using this trowel . There will be ridges and valleys and imperfections . But tomorrow, when the smoothing compound is dry , I will sand everything smooth . I have to say, I’m pretty darned good at smoothing walls . 🙂

I like to use the Plus 3 Joint Compound by the Sheetrock brand. It’s much easier to sand than the standard joint compound . Do NOT use the ” quick set ” version – coatings such as primer , paint , or wallpaper don’t like to adhere to this stuff . It’s made for small patches , not covering entire walls. BTW, for short, we simply call this ” mud .”

Once the walls have been sanded smooth , all the dust vacuumed up, and residual dust wiped off the walls with a damp sponge , then I will apply my favorite primer, Roman Pro 977 Ultra Prime , made specifically for use under wallpaper .

Smoothing Over A Mess

This kind homeowner had the sink / vanity in this powder room removed. This makes it a LOT easier and faster for me to to get the wallpaper up, and with less stress on the paper and fewer relief cuts .

Removing a sink that’s attached to the wall often damages the surface. Here you can see how the workman used spackle compound to cover the torn drywall and other damage.

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Close-up. This isn’t a very smooth surface, and the wallpaper will have a hard time grabbing ahold and adhering. It’s also way too porous and crumbly to support wallpaper.
In the top photo, you see where I have applied smoothing compound on the upper portion of the wall. I’m working my way down.
Once it’s dry, I will sand and prime it, and it will be nice and smooth.

Here’s a shot of the fresh smoothing compound, before sanding.

Some people use a drywall taping knife or a broad knife to apply the plaster-like substance. I prefer the trowel you see in the photo, because it gives me more control and precision.
The 2″ flexible putty knife is for getting into smaller areas. The 3″ stiff ” Hyde ” putty knife is for knocking off high points or bumps on the wall before applying the smoothing compound.
This process is called skim-floating or skim-coating .

I like to use the Plus 3 lightweight joint compound made by Sheetrock . We just refer to it as mud . Find it in the drywall aisle.
The Plus 3 spreads on easily enough, sands easily , and the dust falls to the floor where it can be vacuumed up easily – as opposed to getting air-borne and drifting all over the place.
This box, which is approximately one cubic foot , weights 32 pounds . Ugh. Try carrying that across a parking lot and then up to the third floor of a townhome!

I like to transfer the material to a 5-gallon bucket. This is what it looks like in the bottom of the bucket.
Easy to scoop out. When I’m finished, I use a wet hand to smooth down the surface, wipe residue off the sides of the bucket, then place a thick sheet of plastic over the surface to keep air from drying it out. Then, of course, I put the lid onto the bucket.

Stuff Doesn’t Wanna Stick To Slick

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.

Stains on Wall Around Crib

Look carefully and you’ll see an oval-shaped dark area on this wall. Stains have soiled the high areas of the textured wall. This is where the crib was up against the wall. Probably the child ran her hand or feet across the wall. Over time, oils from our skin can cause stains like this.
Before smoothing the wall, I applied a stain blocker to this area, to prevent anything from bleeding through the new wallpaper.
I like oil-based KILZ Original best, but there are others out there. BIN by Zinsser is another good option.
The smoothing compound and / or wallpaper primer then goes over the stain blocker.
Additionally, once the new wallpaper is up, it’s important to protect the wall and take steps to prevent new stains from developing.

Paint Peeling Off The Wall – A Bad Harbinger

Prior to prepping for wallpaper, I’ve removed a hanging shelf. It had stuck to the paint, and pulling the shelf off the wall also took some of the paint along with it.

This is a bad sign. If paint will release from the wall so easily, it’s an indicator of an unstable surface underneath, that the paint is not able to bond to.

That also bodes poorly for any coatings applied on top of it, such as my smoothing compound, primer, and wallpaper.

The most worrisome of these is wallpaper. Because unlike other substances, wallpaper expands when it gets wet with paste, and then as the paste dries, the paper shrinks a tad and puts stress / torque on the wall. If the underlying surface is unstable, these layers can actually pull apart, resulting in a ” popped ” seam.

This is not a ” loose ” seam and cannot be simply glued back together. It’s layers deep inside the wall coming apart / delaminating from each other, and virtually impossible to really repair.

So what causes this? Do a Search here to read my other posts on this topic. But causes can include incompatible surfaces, such as old oil-based paint covered with newer latex paint, gloss paint covered with new paint without proper prep / de-glossing, chalky or calcimine paint, or coatings applied to a dusty wall.

In all these cases, the top coatings won’t be able to adhere tightly, and can result in what you see here – the top layer(s) of paint pulling off the wall with just a little stress.

Even worse, in my world, is the potential of the surface beneath wallpaper seams coming away from the wall.

Smoothing a Textured Wall, Continued

Continuing from yesterday’s post … The smoothing compound has dried and I’m ready to sand it smooth. This photo gives an idea of what needs to be sanded down. Some areas, such as around electrical outlets, are more irregular and have more raised areas to be sanded down.

Before I get to the sanding, a 3″ stiff putty knife comes in handy for scraping down high areas.

For decades, contractors wrapped sandpaper around a wooden block and used that to sand walls. Then, about 25 years ago, some genius invented these sanding sponges. They’re soft, flexible, easy-to-hold blocks covered with sanding fibers of various grits. They have angles that aid getting into various corners. I find that the edges can be a bit “pointy” and can gouge into the surface, so I often use a scissors to cut off the corners, as you see in all but the one on the far left.

Held against the actual wall.

Don’t forget a dust mask, to prevent inhaling the fine particles. And, yes, this is an N-95 … The same mask that protects us from ingesting the COVID 19 virus also protects the lungs of us home improvement contractors.

Manufacturers have done a good job of creating joint compound whose dust settles to the floor, rather than going air-borne and sifting all around the room. Still, it’s best to take measures to keep dust out of the rest of the home. Here I’ve hung a sheet of painter’s plastic across the wall, to contain sanding dust.

Once I’m done sanding, I’ll use my Shop Vac to clean up the mess, removing dust from both the floor and the walls.

It’s crucial that all dust be removed from the wall. If not, it’s like flouring a cake pan – the wallpaper (or paint) will kinda stick – but not really stick. Vacuuming the wall will not remove all dust. The only way to remove all residual dust is to wipe it off the wall with a damp sponge.

Look at how much dust has accumulated on the sponge after only a few swipes.

The sponge needs to be rinsed clean frequently. Once I’m done, I’ll dump this bucket of dusty water down the toilet (not the sink).
Swipes from the damp sponge will leave wet marks on the wall. These need to dry before moving to the priming step, so as not to trap moisture within the wall surface.

Here I’m rolling on my favorite wallpaper primer, Roman Pro 977 Ultra Prime. I have my paint store guys add just a bit of blue tint, to help me see where I’ve rolled it on. The short angled brush is for cutting the paint in around corners and edges.
I’ve tacked strips of dropcloth along the top of the baseboards, to prevent splatters.

Finished wall, nice and smooth, primed, and ready for wallpaper.

Starting to Smooth a Textured Wall

This is a typical wall texture provided by many builders of new tract homes in the suburbs of Houston.

Wallpaper doesn’t look good hung over this texture, because the bumps will show through. And the high-and-low ridges and dips interfere with good adhesion to the wall. So this accent wall will need to be skim-floated to smooth it before the wallpaper can go up.
In addition, this wall started out with a semi-gloss paint. I worry about my materials being able to stick to a glossy surface.

So, before applying the smoothing compound, I am priming the wall with something that will stick to the gloss paint, as well as provide a matt finish for the smoothing compound to adhere to.

I’ve discovered that my favorite wallpaper primer also works great for this purpose. It sticks to just about anything, and dries almost dead-flat. I like Roman Pro 977 Ultra Prime.

I use a trowel (top) to spread on the smoothing compound. The 3″ stiff putty knife is used to knock off big-ish chunks on the wall, or bits of grit. I use the 1 1/2″ flexible putty knife to apply the smoothing compound in tight spots like around electrical outlets or between a door molding and a wall corner.
The smoothing compound I use is drywall joint compound, and I like the Sheetrock brand Plus 3 version. Search hear (upper right) to see previous posts with photos of this material.

Bottom of photo – trowel sticking to the wall shows you just how tacky this stuff is. Above that are blobs of the smoothing compound waiting to be spread around, and a little bit on the left initially smoothed onto the wall. At the top of the wall you see a section that I have already covered with the smoothing compound. This will dry overnight, and I will sand it smooth tomorrow.
Sometimes I can float a wall, get it to dry, sand it smooth, prime, and hang the paper all in one day. But this texture is so heavy that more time is required for it to dry, so it will need an overnight sit. Some fans, plus the home’s heat and/or air conditioning help to pull moisture out of the smoothing compound and hasten dry time.

Secrete Weapon for Drying Smoothing Compound

Walls need to be smooth before wallpaper can go up, both for good appearance and good adhesion. Once troweled on, the smoothing / joint compound takes a while to dry. I use fans to speed that along.

But in a small room like a powder room, this space heater really helps a lot. I close the door and let this thing run for a while. It will heat up the area quickly. The warmed air holds moisture well, and actually pulls the moisture out of the smoothing compound.

Once the air in the room is hot and humid, I’ll shut off the heater and open the door. I turn on the exhaust fan to pull, and then set a fan in the doorway blowing outside air into the room, exchanging damp air for fresh, dry air. This works amazingly well.

I keep my smaller fans running inside the room along with the heater. But my more powerful floor fan – I’ve learned the hard way that operating that and the heater at the same time will trip the electrical circuit. So it’s a juggling act between those two very useful tools.

I really like this heater, because it’s older and doesn’t have all those safety features that cause them to shut off when you want them to be on. But don’t worry – it still will stop if tipped over, and when the room gets to the set temperature, it will turn off.

Fixing Drywall Damage From Where Vanity Was Removed

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!