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.

Sometimes (Rarely) You Have To Hang Over Old Wallpaper

It’s always best, for many, many reasons, to remove old existing wallpaper before hanging new. Especially if that old paper is vinyl or non-woven or thick / textured.

But sometimes, it just isn’t feasible. Here, the original installer didn’t use a primer, so his wallpaper bonded to the bare Sheetrock and would not come off without taking the top layer of drywall along with it. I worked at it for an hour, but only removed about 10 square feet – and much of that included damaged drywall.

So, time to try another tact. This method only works with paper (not vinyl or anything thick or textured), and the original paper has to be tightly secured to the wall. First, I removed any loose areas – usually over joints in the drywall that have been coated with joint compound (it’s porous and sucks the paste off of the wallpaper).

Then I took joint compound and skim-floated over any uneven areas or any sections of torn drywall, and all wallpaper seams. Seams may feel flat, but once new wallpaper is on top of them, the vertical lines of seams will telegraph through and be visible.

Once that was dry, I sanded smooth and “feathered out the edges,” then wiped off all dust with a damp sponge. See top photo.

Then I rolled on my favorite wallpaper primer, Roman Ultra Prime Pro 977, and made sure to cut in around the edges with a trim brush. This primer sticks to just about anything, including the light acrylic protective coating on most paper wallpapers, such as what I had today. It doesn’t penetrate the joint compound and cause the torn drywall to stretch or wrinkle. Nor will it allow moisture from the new wallpaper paste to penetrate through. And it’s lightly pigmented, so it works well under thin wallpapers.

Plus, it is formulated to receive and hold wallpaper, makes installation easier in many aspects, resists tension on the wall as wallpaper dries and shrinks, and eases removal of the wallpaper in the future.

Once the primer is dry, the room will be ready for its new wallpaper.