When a wall surface starts to deteriorate, it appears to be a major problem.
While repairing a large surface can be labor-intensive, it may not require drastic action, and it may not be all that difficult to do.
A reader from Baltimore, who happens to live in one of our favorite ZIP codes -- one where we've both renovated houses, has what sounds like a serious wall problem.
"I have a stairway where the wall looks ugly," he writes. "Paint is falling off and the walls are not smooth. I would like to repaint. The plaster wall is too sandy to hold paint. The cement wall is rough and the ceiling is curved. Can I Sheetrock? If so please tell me how to anchor Sheetrock to the cement wall. What can I do about the curved ceiling?"
The first step is to figure out exactly why the old paint is peeling. There are a number of potential reasons. Leaks from doors, windows and roofs can cause interior surfaces to deteriorate. Also, in many old houses, the plaster was meant to have a finish coat of wallpaper, applied directly over the sandy "brown coat." A finish layer of white plaster was never applied.
Caulking around doors and windows and checking the roof for leaks may stop the deterioration. Then, whatever the cause, it sounds like the walls need to be resurfaced.
Drywall, or Sheetrock, is installed over furring strips nailed into the wall. We don't recommend retrofitting drywall in a staircase because it will narrow the stair and is likely to stick out over or cover existing trim. It's better to repair the original surface.
If the plaster is sandy, start by removing everything that is loose. The problem with this is that crumbling paint in an old house tends to contain lead, and scraping it can fill the house with lead dust. Even a tiny amount of lead dust is dangerous to small children.
The accepted way to deal with lead painted walls is to encapsulate them -- that is to cover it with another surface, sealed at top and bottom. But covering up original surfaces can destroy the integrity of an old house. The answer is to proceed with caution. If you are generating dust in an old house, you need to wear protective clothing, or at least old clothes that can be discarded (if you don't throw them away, wash them apart from family laundry). You need an adequate dust mask -- not the paper ones. The area being worked on should be covered with plastic, so dust falls on plastic and not on other surfaces. And you need a special vacuum, called a HEPA vac, to clean up when the job is done. In some areas, including Baltimore, lead-paint removal can be done only by licensed lead-paint removal specialists. Check with your town or local jurisdiction to find out how to proceed.
Once the walls have been cleaned of everything loose, the next step is skim-coating, a process of applying thin layers of finishing compound, such as Durabond 90, over the uneven surface.
Use a 12-inch drywall knife and work quickly with small amounts of compound to cover the surface. Use thin coats; it may take two or three. Be careful not to leave ridges that will have to be sanded off. (Small ridges left in the early coats may be knocked down, or smoothed out with the knife before applying subsequent coats.)
After the first coat is dry, use drywall tape to patch any remaining cracks or small holes. Let each coat dry thoroughly before applying the next; each coat should dry overnight.
Since the final coat is the only one you want to sand, you may want to use regular joint compound. It's easier to sand.
This resurfacing method will work on the curved ceiling, though it may take some practice with the knife to get a smooth surface with no ridges.
It is possible to secure drywall to concrete block or brick walls. The best way is to install 3/4 -inch furring strips nailed to the wall with masonry nails. However, it's hard to nail furring strips and get them tight. The brick or block tends to crumble. A better treatment might be to nail galvanized wire lath with roofing nails and replaster over the lath.
Mr. Johnson is a Baltimore construction manager. Ms. Menzie is a feature writer for The Sun.
If you have questions, tips or experiences to share about working on houses, write to us c/o HOME WORK, The Sun, 501 N. Calvert St., Baltimore, 21278. Questions of general interest will be answered in the column; comments, tips and experiences will be reported in occasional columns.