Q: I have a bathtub and shower combination, and the walls need some work. The house is old, and the shower walls are made of some type of fiber sheets that are warped and need to be replaced.

What is the least expensive way to repair the shower and make the walls watertight?

A: It sounds like you need a new tub surround. Your shower walls were probably made of a material called Marlite, which went out with disco.

Tub surrounds are made from a variety of materials, including plastic, cultured marble and Corian. The least expensive material, plastic, starts at less than $100.

The kits come in five pieces. There are three panels that attach to the three walls surrounding the tub and two corner pieces.

You will first need to remove the hardware from the front wall. Take off the tub spout and the handles. The tub spout will either unscrew or will have a set screw underneath it that holds it to the pipe.

Each handle will have a small plastic cover that hides a screw. Remove the screw and pull off the handle. The shower head and arm are sometimes above the surround, so you may not have to remove them.

You must remove the old surround. If it’s in as bad of shape as it sounds, it probably will easily come off of the wall. If there are problems removing it, you may damage the underlying wall. Often when removing old ceramic tile to install a tub surround, parts of the wall come off with the tile.

If you damage the wall, you must repair it. You may even look at the wall and decide that it needs to be replaced anyway. In any case, you can repair any damage in the wall with water-resistant greenboard.

If the walls are in good shape, you need to cut and apply the sheets to the walls. The back and side walls are easy, but the front wall needs some holes that you will have to cut.

You can measure the locations on the wall and transfer them to the surround sheet, but this is risky because your measurements have to be very accurate. It is much safer to make a template and then transfer the exact location of the holes to the sheet.

You can use a piece of cardboard or paneling to make a template. If you use cardboard, push it into the protruding tub spout pipe and handle stems, and it will make indentations to mark where you are to cut. Use your template to transfer the marks.

You can cut the hole for the tub spout pipe with a 1?-inch hole saw. This saw chucks into a drill and cuts as the drill spins. It also works well for two- or three-handle shower valves.

If you have a single handle that controls both the hot and cold water, you will need a larger hole. Drill a pilot hole and then use a jigsaw with a fine-toothed blade to cut the hole.

The size of the hole depends on the size of the valve and, most importantly, the size of the decorative plate that will cover it.

Once the holes are cut, follow the manufacturer’s instructions on the order that the panels are to be installed. Do a dry run and hang the panels on the wall with tape. Use a pencil and make lines on the walls to mark the locations of the panels. Take the panels down and get the adhesive ready.

For the inexpensive surround, you will use panel adhesive and run thick beads on the wall and the panel. Push the panels in place. You can use tape to hold everything in place until the adhesive sets up.

The corners where the panels meet do not have to be perfect because they will be covered with the corner pieces.

Use the adhesive for the corner pieces as well. After everything is in place, use silicone caulking to seal the perimeter of the surround, as well as both edges of the corner pieces. Finally, seal the tub spout and the escutcheon plates to make them water-tight.

Depending on the size of the old surround and the size of the new one, you may have some drywall work to do. If the new surround doesn’t cover as much area of the wall as the old one, you will have to texture and paint small areas, which is a separate project of its own.

Maybe you can worry about doing that job next weekend.

Mike Klimek is a licensed contractor and owner of Las Vegas Handyman. Questions may be sent by email to handymanoflasvegas@msn.com. Or, mail to 4710 W. Dewey Drive, No. 100, Las Vegas, NV 89118. His Web address is www.handymanoflasvegas.com.