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Tale of the Tub Continues

House Doctor | Gary Dymski

January 2, 2003

A few weeks ago, readers visited the catastrophe in my family's main bathroom - no, not the hardened globs of toothpaste - but a decaying shower and tub wall. Since that column, a few neighbors (and a few more readers) have revealed they have similar problems: collapsing tub and shower walls. The reason for these wall failures is the use of greenboard - water- resistant wallboard - as a backer for ceramic tile in areas exposed to water.

This column, and a few in the near future, will focus on rebuilding my tub wall. My neighbors are on their own.

The first step was ripping out the old wall. Under normal circumstances, demolishing a tile tub wall is difficult. That's assuming, of course, the wall was properly built. The last time I demolished a shower wall, a rented electric demolition hammer - a small jackhammer - was used to chisel through layers of tile, metal lathe and concrete.

This time, the small sledgehammer was more than enough. A 2- foot-by-2-foot portion of the longest wall already had collapsed. To remove what was left, I pounded firmly between studs, making a hole in the tile and drywall. Using gloved hands, and occasionally tapping lightly at a chisel, I was able to easily pull large portions of the remaining wall from the studs.

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Protecting the tub itself was the most difficult part of the demolition. To keep broken pieces of tile and wallboard from scratching the tub floor, I taped cardboard, and several layers of thick brown wrapping paper to the tub floor and walls. After pulling down pieces of wall, I carefully stacked them inside the lined tub.

I thought another challenge would be saving the ceiling. Since the tile wall went right to the ceiling, I was sure pieces of ceiling wallboard would be damaged as the wall came down. By scoring the very top of the wall with a utility knife, slicing through wallboard tape and the caulk line, the tile wall came down without damaging the ceiling wallboard.

Although the wall fell easily, this still was a dusty, dirty job. I wore a dust mask, gloves and safety glasses for the demolition. To keep dust from spreading to the rest of the house, I kept the bathroom door closed. I worked with the window open and kept the bathroom exhaust fan running.

In addition to moldy, mildewy wallboard, there was water-damaged fiberglass insulation to deal with - because the largest shower wall also is an exterior wall, it was lined with battens of insulation. Moisture from the tub and shower had seeped behind the wall and rotted the paper lining of the insulation. New insulation was needed. I used three newer garbage containers, all with wheels, to dispose of the broken bits of wallboard and tile. Then I removed the fiberglass insulation and carefully placed it in large plastic garbage bags.

A cordless drill and pliers helped me remove drywall screws and nails from the studs, and my Shop-Vac took care of small bits of tile and wallboard.

After demolition and cleanup, which took about three hours, I needed to redesign a portion of the shower wall. When it was originally built, the longest tub wall extended about 8 inches past the standard-size tub (32 inches wide by 5 feet long). This extension was built into a handy bench at the far end of the tub, for storing soap and shampoo and even for sitting in the shower. However, as constructed, the tub could not support a standard sliding glass tub door. A custom tub door could be built for $700, more than three times the cost of a standard door.

My family likes the bench but also wants a sliding tub door. I want a tub door, too, but not necessarily one for $700. So I built a wall extension, 8 inches wide by 63 inches high, out of 2-by-4 studs, that will allow me to use a standard door size (about 60 inches by 60 inches). This extension was attached flush to the outside edge of the bench area.

The last task before lining the wall with a substrate was insulation. I used paper-lined fiberglass battens and stapled them to the inside of the studs.

While I was tearing out and building, my wife was shopping - for tile. She drew the easy assignment. Naturally, I am faced with another major challenge: choosing a substrate. Do we go with a reliable favorite, a cement backer board or a new, lighter, labor- friendly fiber cement board by Hardie?

That's for next time.