Like much of the United States, we have had our share of rainstorms in the Windy City this year. The morning after a particularly intense one, I walked out into the hallway to find that even though storm had ended, it was still raining inside. I had been wanting to take care of the peeling paint and wall cracks in the front hall since I moved in, but now, with the paint falling off the ceiling in big sheets, I had additional incentive....
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As the ceiling dried, the paint started peeling and the minerals in the plaster
started forming yellow crystals. (c)2013 Eric E. Paige
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After the roofing company fixed the problem and the ceiling and walls had dried, I got down to business, or I guess in this case, up to business. The first step was to scrape off the peeling paint and the efflorescence (mineral crystals that formed as the water evaporated).
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Scraped, sanded, and washed.
(c)2013 Eric E. Paige
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I also found a couple spots of mildew where water had gotten trapped behind loose paint. I used a spray bleach cleaner from a dollar store, but you can also make your own solution; most brands of bleach have instructions on the label. I then wiped down the walls and ceiling with water to remove any residues (there were tannins that leached from the ceiling joists).
Once I had a clean, dry surface, repairs could start. There are a lot of options for filling cracks, and if you have only a small amount of repair, an inexpensive jar of lightweight spackle will work just fine, but as I had some large cracks to fill and a time limit (the owner of the building was in the midst of moving and we needed to get things done quickly so it didn't interfere with showing his unit), I chose to use a setting-type joint compound. Whereas regular joint compound dries and you can rework it by adding water, the setting type cures, like cement. You have to work quickly, but the trade off is less waiting time between coats. For more information on the subject, see my post:
Reclaiming Space...Bringing A Sun Porch From the 70s Into The 21st Century.
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Tools of the trade, taping knife, joint tape, and
joint compound. (c)2013 Eric E. Paige
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There were three main types of repairs I had to do: filling holes, filling cracks, and skim coating. Filling small holes is a relatively simple repair: you fill the hole with the compound, level it off with your putty or taping knife, and sand it. Sometimes, the compound shrinks and you get a slight depression where the hole was, another coat of compound and some sanding will take care of this.
Filling cracks can be more difficult. They can be the result of the building settling, which is an ongoing process, so the cracks often reappear. The minor cracks, I did just spackle over, but for the major ones I filled and reinforced them. For some of the mid-sized cracks (up to about 1/8") I used joint tape, a paper tape used to cover the gap (aka 'joint') between two pieces of sheet rock. I bought the smallest roll they had, as I only needed a few feet of tape. There is also a mesh 'tape' that has a light coating of adhesive to hold it in place while you 'mud' over it with the compound, but I find the paper is cheaper and much easier to work with.
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This deep crack is caused by the building settling. If I just
filled it with joint compound, the crack would come back.
(c)2013 Eric E. Paige
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I filled the cracks with the joint compound, spreading it out a bit wider than the tape. I then put a very light coat of the compound on the back of the tape (this helps ensure it all adheres to the surface and that you don't get air bubbles -- trust me, taking your time here will save you headaches later!). I then pressed the tape against the wall, carefully smoothing it with my taping knife to ensure it was well adhered and carefully applied a very thin coat over the top of the tape. Once the compound was dried, I applied a second coat which I feathered out well past the edge of the tape. If you look at a piece of sheetrock you will notice that the long edges are indented slightly, this is to accommodate the thickness of the tape and the joint compound. Since I was repairing a crack, there was no recessed area, so the next best thing is to cover the tape completely, gradually reducing the thickness of the coat as you get further from the tape. If you are using a taping knife rather than a putty knife and look down the edge of the blade, you will see that it has a slight bend in the middle. The high spot in the center helps ensure that more mud gets put over the taped area.
To repair the deep crack by the door way, I wanted something a little heavier duty, so I used some scraps of khaki I cut from a pair of ripped pants. I wet the fabric first, to ensure it gripped evenly to the mud. If you want to go a little more high-tech, your home-improvement or hardware store sells various patching materials in metal or fiberglass, to cover large holes and cracks. The procedure is basically the same, only if you have a self-adhesive patch, you only put mud on top of the patch, not underneath.
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A layer of mud fills the crack and makes a base for the patch
(c)2013 Eric E. Paige
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Scraps of khaki will reinforce the joint.
(c)2013 Eric E. Paige
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The khaki, covered with more mud. The
high spots left by the taping knife will sand
off pretty easily. (c)2013 Eric E. Paige
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The final type of repair was skim coating. Since only some of the paint peeled, had I just painted over everything, you'd see a line where the paint chipped. To remedy this, I simply applied a thin layer of compound to even out the thickness. I didn't have to cover every square inch that had lost paint, but merely applied the compound over the uneven area and pulled from the paint (the high spot) to the plaster (the low spot) gradually tapering off (feathering), the amount of compound, just like I had done to cover the tape.
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Skim coated, mud feathered out past the sharp
edges where the paint peeled.
(c)2013 Eric E. Paige
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A second coat fills any spots that were missed
and any low spots that formed after the
compound set.(c)2013 Eric E. Paige
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Once all of the joint compound had cured I sanded it smooth, taking care not too sand too hard and expose the tape. For the walls, I used a fine grit sanding sponge. The sponges last a long time and can be rinsed out, dried, and used again. On the ceiling I used a pole sander to knock off the real high spots and then feathered things out using a sanding sponge. After the first sanding, there were some some spots that weren't even. Since they were relatively shallow and would dry quickly, I used a premixed, lightweight joint compound to fill them. Sanding is a messy business, so a dropcloth, mask, and goggles, are must.
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Sanded, primed, and ready for paint!
(c)2013 Eric E Paige
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I know a lot of paints say they are self priming, but stain-blocking primer is relatively inexpensive and dries in an hour. My walls and ceiling were a flat finish, so I only primed over the patches and exposed plaster. If I were using a glossier finish, I would of painted over the whole surface to ensure that the new paint doesn't 'flash' (variances in sheen because of the way the finish adheres to different surfaces). The stain blocking primer I used does a good job for most applications and is a waterborne product, so clean up is a breeze and the odor is low. There were a couple of spots where more tannin leached through the paint, causing the primer to yellow slightly in some spots. Before coating with the final paint (in the Fall, when it is cooler, and I want to be inside), I will spot prime them with an oil or shellac based stain blocking primer, and then probably go over that with a bit of the waterborne primer, just to make sure the color takes evenly.
