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 .

Wall Prep Ahead of Wall Re-Do

This wallpaper in a Houston Heights townhome’s breakfast area was hung by “the contractor’s guy ” and he ran into some problems. First, I suspect the wall had not been adequately coated with a primer designed for use under wallpaper . This may be a large part of why the paper has come loose from the wall in places, and shrunk and gaps at the seams.
The wallpaper is an old-fashioned British pulp material , which is quite different from the non-woven material that this company usually prints on. If the installer was not familiar with hanging a pulp, yes, he can have a tough time of it.

There are other issues that the homeowner is unhappy with, such as tears, slices, patches, and, of course, these un-stuck seams. I’ve posted more pics previously, if you can Search to find them.
My task is to get the paper off and then prep the wall for hanging new material.

Most of the paper pulled off the wall easily. But there were areas where the guy had used a stronger adhesive to try to hold the edges down. Those would not come off the wall without causing damage to the wall. So I pulled off the top, inked layer and left the paper backing on the wall.
This stuff is porous and will bubble when coated with a water-borne primer , and with wallpaper wet with paste.

So I sealed these areas – I sealed the entire wall, in fact – with Gardz (by Zinsser ). This stuff is pretty incredible. It’s a thin, watery primer / sealer that soaks into the surface and binds loose components together, then dries hard and solid .
Latex paints and other water-based products (usually) won’t penetrate it, so won’t cause the underlying material to re-wet, expand , and bubble .
Just a note … due to pandemic and other supply chain related shortages , Gardz has become difficult to find. This can was about 1/4 full and I had it sitting behind my trash can, intending for weeks to toss it out. Now I’m glad that I procrastinated!

Once the Gardz sealer was dry, I skim-floated over it with joint compound , a.k.a. ” mud .” In most areas of the wall, my skim coat was as thin as possible, but I did have to make it much thicker over the areas with the paper backing stuck to the wall.
I set up three fans , and also used my heat gun , to get the smoothing compound to dry. I like the Plus 3 version made by the Sheetrock company. It sands easily and doesn’t make too much air-borne dust.
It took a couple of hours to dry. Then I sanded it smooth , vacuumed up the dust with my Shop Vac , used a damp sponge to get residual dust off the wall , and then let the wall dry once again.

Finally I applied a coat of my favorite wallpaper primer, Pro 977 Ultra Prime by Roman. I used a paint roller to roll it on to the main areas, and an angled trim brush to cut in around the ceiling and moldings.

Here is the wall all smoothed and primed .
Originally I had planned to strip , prep , and hang this half-wall all in one day. But ended up the prep took more time than I anticipated (about 8 hours ) , so we’ll let the primer dry overnight and save the wallpaper installation for another day.
The wallpaper pattern is called Strawberry Thief and is by the famous William Morris designer from the very early 1900’s . I’m sure seeing a surge in interest in his patterns, particularly this one. Do a Search to see other jobs I’ve done with it.

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.