Posts Tagged ‘joint compound’

Mirror “Tar” Will Bleed Through Wallpaper – Prevention

May 17, 2017

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Originally, this powder room in a newish townhome in the Rice Military neighborhood of Houston had a mirror that was glued to the wall. Removing it left globs of mastic (tar-like adhesive) stuck to the wall. See Photo 1.

Mastic is petroleum-based, and it, like other similar substances such as grease, oil, and crayon, as well as other compounds like blood, rust, water, tobacco tar, and others, will work their way from behind the wallpaper up through it and then onto the surface, causing an unsightly stain.

KILZ Original oil-based primer and stain blocker is a superb product for sealing these substances. However, I feel more confident if the suspect material is removed entirely.

The best way to do this is to take a Stanley knife (utility knife / box cutter) and cut around the stain and into the wall. Then you can use a stiff 3″ putty knife to peel up the top layer of drywall, taking the staining material with it.

This leaves a patch of Sheetrock without its protective top layer. See Photo 3. These layers of torn Sheetrock will absorb moisture from anything you put on top (paint, primer, joint compound, etc.), and will swell, creating ugly bubbles that will mar the finished job.

So I brushed on Gardz, a penetrating sealer / primer by Zinsser. This is cool stuff, because it soaks into the surface and then dries hard, binding everything together.

In Photo 4, I have skim-floated over the areas where I have cut out the mastic. To skim-float, I trowel on a smoothing material called joint compound. Once that is dry, I will go back and sand it smooth, creating a perfectly smooth surface ready to accept the new wallpaper.

Fixing a “Hot Mess”

April 18, 2017

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The homeowners of this house in Fleetwood (west Houston) tried to remove the wallpaper from their powder room on their own. They did a reasonably good job at the start, but soon realized that they were in over their heads.

In the top photo, they have removed the top layer of wallpaper from the wall on the left. The problem came when trying to take off the white backing layer. Their efforts resulted in torn drywall (second photo). Torn drywall is very bad, because it will leave uneven areas under the new wallpaper / paint. Worse, it will bubble when the moisture from the wallpaper paste or latex paint touches it, and that will leave bubbles under the new wallpaper / paint.

These homeowners were smart enough to stop before more damage was done, and called in the pros (me).

I finished stripping off the old wallpaper, using methods that caused less damage to the drywall. There was one patch of original wallpaper, a foil-type that dated back to the build date of 1976, that would not come off without a lot of damage to the wall. I left that section on the wall.

Once all the paper was off that would come off, I sealed the torn drywall and other unstable surface areas with Gardz, a penetrating sealer. Once that was dry, I skim-floated the entire room with “mud,” (joint compound). When that was dry, I sanded the surface smooth. Then I vacuumed up the dust, then wiped any residual dust off the walls with a damp sponge.

Lastly, I rolled on another coat of the penetrating sealer Gardz. It will dry hard and tight, preventing the torn drywall from bubbling, and holding all the loose or unstable areas together. It is also a good primer for wallpaper, so tomorrow the walls will be prepped and ready for their new décor! See last photo.

Using 20-Minute “Mud” to Repair Sheetrock Damage

March 31, 2017

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When the homeowners had their powder room vanity top replaced, the shorter new backsplash left a 1″ area of torn drywall around the top of the new backsplash. There was a height difference between the drywall and the wall (which was covered with at least two layers of old wallpaper). This needed to be evened out before the new wallpaper could go up.

Because torn drywall will bubble when it gets wet, I used a penetrating sealer called Gardz to prevent this by sealing the raw area. Once that was dry, I used 20-minute joint compound to “float” over the damaged areas.

The bag says “5” (see photo), but that is misleading. What they mean is that you have five minutes to mix the powdered material with water, stir smooth, and then work with the stuff, before it gets stiff and hard. The actual drying time is more like 10-20 minutes, and sometimes longer.

Once it’s dry, it can be sanded smooth. Wipe off the dust with damp sponge, let dry again. Then it can be sealed with a primer, and I like the penetrating sealer Gardz, once again, to seal this porous joint compound material.

Getting the Walls Smooth, Cont’d.

February 16, 2017
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Yesterday’s post showed you the extremely heavy texture on the walls that needed to be smoothed before wallpaper can go up. In the first photo above, you see the walls after I applied the first coat of smoothing compound.

Once that had dried overnight, I sanded it. Since it started out so thick and uneven, it was impossible to sand it completely smooth, as you see in the second photo. Some paperhangers would hang on this, but I want the walls to be a perfectly smooth as possible, so no bumps show under the paper.

So floated the walls again, this time with a very light skim coat. It dried relatively quickly, and I sanded the walls a final time. The third photo shows how smooth they turned out.

A lot of work, some sore muscles, and SIX BOXES of joint compound!

Prepping Heavily Textured Walls for Wallpaper

February 15, 2017
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Wow. Some DIY remodeler / house flipper loved this textured wall finish, and sprayed it on EVERY WALL AND CEILING in this otherwise-beautifully-updated home near Gessner & Kempwood. The young couple who bought the home want wallpaper in their two daughters’ rooms and in a front room study, plus they want chalkboard paint on one wall in the kitchen.

Wallpaper looks best and sticks best to smooth walls, and the chalkboard wall needs to be perfectly smooth, so I am spending two days smoothing these surfaces. The wallpaper will go up later.

Today I skim-floated the walls with joint compound. (It’s kind of like plaster, and is applied with a trowel.) I went through nearly FIVE boxes of the stuff (see photo). Each box is 44 lbs. Need I say that my arms and shoulders are tired and sore? 🙂

Applying it thickly enough to cover the 1/4″ – 1/2″ bumps means that it will take a looong time to dry, so I have turned on the heat in the house (to help draw moisture out of the smoothing compound) as well as the house fan (to circulate air), set several fans up blowing against the walls, and left it to dry overnight. Tomorrow, I will sand the walls.

Because the skim coat was so thick, even when it is sanded, the surface will not be perfectly smooth, and will also have many holes caused by air bubbles. So I will trowel on a second, much lighter coat, to cover these irregularities. With the heat cranking, and the fans blowing, this second skim coat should dry fairly quickly.

Then I will sand one final time, vacuum up the dust, wipe the walls free of dust with a damp sponge, and finally roll on a sealing primer called Gardz.

The painters can then apply the chalkboard paint to the kitchen wall. And when I come back to hang wallpaper in a month or so, the messy part of the job will be over and done with, so no more dust or mess or smells in the clients’ home – just new, pretty wallpaper for the little girls’s rooms and for Mom’s study.

Wallpaper Wants To Sit On A Smooth Wall

February 8, 2017
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The walls in this powder room were way too heavily textured (Photo 1) to even think about putting wallpaper on them. For one thing, those ugly bumps would show under the paper – and might even poke holes through the surface. For another, the wallpaper would not have a smooth, intact surface to cling to, resulting in poor adhesion.

So I smoothed the walls. To do this, I trowled on joint compound, (we nick name it mud), which is a plaster-like substance used mostly for drywall installations. The initial layer was thick, and had to dry overnight.

In the morning, the surface was dried, as you see in Photo 2. Dry, but way unacceptable for wallpaper … All of those ridges and uneven surfaces would show under the paper.

I sanded this surface down, and it was much better – but still not acceptable for wallpaper.

So I skim floated again, with a very thin layer of mud. Once that was dry, I sanded one more time. And ended up with the perfectly smooth walls you see in the 3rd photo.

In the last photo, you see the wallpaper on the wall, perfectly smooth, and with no signs of bumps or texture or ridges or uneven areas.

Patching a Hole in the Wall

December 11, 2016
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This bathroom had a ceramic toilet paper holder that was recessed into the wall. It was ugly, outdated, and in the wrong place (visible from the hallway), so the homeowners wanted to get rid of it. But that left a hold about 6″ x 4″ that would leave a dent under the new wallpaper.

The homeowner was running errands, so I asked him to pick up a piece of drywall that I could use to patch in the hole. Taping and floating can take a long time to dry, and I wanted to hang paper that day, so I used a different technique.

I cut the piece of drywall about 2″ larger on all sides than the hole. Then I cut off about 2″ of drywall all around the outside edges, leaving a chunk of drywall in the center that was just the size and shape to fit into the hole. I left the top layer of paper on the drywall, which formed a sort of flap all around the center piece. In the second photo, you see me removing some of the drywall, but leaving the inner section, and also leaving the paper flap.

In the third photo, I have inserted the drywall piece into the hole, and the flap is extending 2″ all around the piece. I have floated over the whole thing with joint compound. Next I set a heater and a fan on it, to get it to dry quickly, while other parts of the room were being prepped.

Once dry, I sanded it smooth, refloated to cover minor imperfections, and sanded again, then wiped off dust and primed. The last photo shows the final patch. If you didn’t know where to look, you would never notice it!

From Pimply to Smooth

November 2, 2016
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Today I prepped two accent walls, to be ready for wallpaper tomorrow. The first step was getting rid of this fairly heavy stipple texture.

To do that, I take a putty knife and knock off the highest bumps, then trowel on joint compound, which is something like plaster. Once it’s dry, I sand it smooth, vacuum up the dust, wipe dust off the wall with a damp sponge, and then apply a penetrating primer to seal it and prepare the wall to accept wallpaper.

The second photo shows how nice and smooth the wall is. And, not to toot my own horn, but I am much better at it than most painters or handymen, so no need to hire one of them to smooth the walls – I will most likely have to redo at least part of it anyway. 🙂

Why do the walls need to be smoothed? First of all, the bumps showing under the paper just look bad. Slipshod and uncaring. Second of all, if the wall is textured, then the wallpaper can only adhere to the tops of the bumps, which is not very secure at all. When the wall is nice and smooth, and properly primed, there is a sound surface for the paper to come in contact with and hold tightly.

Getting Smoothing Compound to Dry Quickly

August 30, 2016

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Here in Houston, many homes have textured walls. Texture prevents good adhesion of the wallpaper, and it looks, well, it looks cheesy under the wallpaper. So I do a lot of what we call “skim floating,” to smooth the wall. This involves skimming the wall with a plaster-like substance (joint compound, also referred to as “mud”).

Nothing can progress until that mud is dry. It will dry overnight, but then the homeowner would have to pay for a second day of labor. So I try to speed the process so that everything can be done in one day. Here you see my two box fans and one heavy duty fan, all aimed at this one short accent wall. The texture was heavy, and so it took a longer than usual time for the joint compound to dry.

Turning the air conditioner down (or the heat up) and having the house fan set to “on” also helps to circulate dry air through the room and pull moisture out of the wall. In a small room like a powder room, I use a space heater and close the door to keep in the heat. I also have a heat gun that can be used to spot dry stubborn areas.

Note that the black fan and the heaters all pull a lot of power, so they cannot be used at the same time or they might trip the circuit breaker. So it becomes a juggling match of turning something on and off, moving the fans to different positions, opening the door to let hot humid air out, etc.

Once the smoothing compound is dry, I sand it, then vacuum up the dust, then wipe residual dust off the wall with a damp sponge, rinsing it frequently. Then the wall has to dry again briefly, and then the primer gets rolled on. That needs to dry for about an hour, and then the wall is finally ready for wallpaper.

Drying Walls

July 7, 2016

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These walls have a thick texture that needed to be smoothed before I could hang the new wallpaper. In the photo, I have finished skim floating the walls with mud (joint compound). Now they need to dry, before I can sand them smooth.

The homeowner has the air conditioning cranking away, which helps to pull humidity and moisture out of the smoothing compound. In addition, I have set up fans to move air around the walls. Two box fans are affixed to the shelves on ladders (secured with bungee cords), and one very powerful fan is sitting on the floor aimed up at the wall.

Sometimes the joint compound can be induced to dry in an hour or two this way. But in this case, because the texture was so thick, and because the semi-gloss paint beneath the smoothing compound slows drying, I needed to let this set-up run for a few hours. The fans sped up the drying process, and once they were turned off, the walls were left overnight to dry further.

Come morning, I was able to proceed with sanding and the rest of the prep and installation of the new wallpaper.