Location may be king in the real-estate world, but inside our homes, where we do most of our living, square footage reigns supreme. How many times have you wanted an extra bedroom or wished for another 200 sq. ft. in your kitchen? Unfortunately, some dreams are more difficult to realize than others. To add even a modest kitchen bump-out requires dedicated foundation and roof additions, plus loads of mechanical work. This can eat up a home-equity loan long before you get to the new appliances that you had your heart set on. The same kind of shock is in store for those with the look of a fourth bedroom in their eyes. Still, each year, many people take the plunge on these rooms and wind up with a home that's a lot more enjoyable for their whole family.

Bathrooms, however, are a different matter. Because of their typical location, it's very difficult and expensive to expand them without stealing square footage from an adjoining room. In a house where you're feeling the pinch, this is a bit like robbing Peter to pay Paul. But there is another place to pick up some space, albeit a modest amount, without taking down a wall or sacrificing a bedroom closet. It's sitting right there in your bathtub, the part you don't use when you're always taking your daily shower.

By replacing a standard 5-ft. tub and shower with an oversize shower stall, we were able to make a cramped, dated bathroom feel bigger and work better. We did have to sacrifice the tub in this bargain. But if you have another full-size bath in your home, you can use that tub the one evening a year you actually have time to take a bath.

Finding a shower
If you feel like doing what we did, your first task will be looking at shower stalls. The better units come in one of two materials, acrylic or fiberglass, and in one of three different configurations: single-piece, 2-piece or 3-piece. The acrylic units tend to be stiffer and heavier than their fiberglass counterparts, and their finish is supposed to be a bit more durable. They're also quite a bit more expensive, two to three times more depending on size and features. In light of this, a fiberglass unit is a good alternative if you're watching your budget closely. As long as they are installed properly, with adequate support for the shower floor, these units should provide years of troublefree service.

Many acrylic showers include a molded ceiling as part of the unit. Fiberglass showers, on the other hand, generally don't. However, several manufacturers offer a dome top that can be mounted above a standard shower to provide a completely enclosed stall. The only drawback to using one of these domes is that they usually provide less headroom than the ceiling-equipped acrylic showers. So, tall people should proceed with caution.

For a retrofit installation, a 2- or 3-piece model is best. Usually, access to a bathroom is limited and a 1-piece unit will not fit through a normal bathroom door. A multipiece shower can be brought into the room in sections and then assembled in place, thus eliminating the need for what can be extensive demolition work.

For this job we chose a 48-in.-long 2-piece shower made by Universal Rundle. It's called Mars II and its model number is U-R 6830. We also added an optional dome top, model No. U-R 6632.

One last word to the wise: The plumbing changes that are required for this job will vary, depending on your specific room and the plumbing codes in your area. Be sure to consult your building inspector before proceeding with anything.

Removing the old shower
Begin by turning off the water to the bathroom. In most homes, there are shutoffs in the basement for the bathroom's supply lines. Next, take off all the knobs and trim from the existing fixture. Start by loosening the screw that holds the knob to the water-supply valve. On many units, you'll have to pry off a cover cap to get access to this screw.

Pull off the knob and remove the escutcheon by loosening the screws that hold it to the valve body (Photo 1).

Pull off the knob and remove the escutcheon by loosening the screws that hold it to the valve body (Photo 1).

Next, grab the spout with slip-joint pliers and remove it by turning in a counterclockwise direction (Photo 2).

Do the same with the shower-head arm (Photo 3).

The drain is held to the tub by a 2-piece assembly: a strainer piece on the top surface of the tub that is threaded into the drainpipe tube, also called a drain shoe, below the tub. To remove the strainer, grip its webbing with a pair of pliers and turn in a counterclockwise direction (Photo 4).

Next, strip the tub walls of any tiles or panels using a flat bar (Photo 5). On our job this meant prying off three wall panels. Then, remove the drywall or plaster to expose the studs around the tub and pull the nails that hold the bathtub flange to the studs. At this point the tub can be removed.

If the tub is steel, you can grab it on the long side and tip it toward you to remove it. Plan on having a helper for this job, because these tubs are extremely heavy and awkward.

If you have a cast-iron tub, removing it requires a different method. These tubs can weigh more than 400 pounds, so it's impractical to remove them in one piece. Because cast iron is brittle, however, it's fairly easy to break the tub into manageable pieces with a sledgehammer. Just be sure to wear eye and hearing protection when you tackle the job.

Changing the waste lines
Once the tub is out of the way, remove the wall that enclosed the end of the tub. First, cut the plumbing supply lines that run up through the wall. Use either a hacksaw or tubing cutter. Remove the studs, one at a time, from the wall and pull out the top and bottom plates.

To get access to the waste lines, you must remove a section of floor. On this project, we had to remove the toilet before we opened up the floor. (For information on removing a toilet, see "Trade Up To An Efficient Toilet" on page 86.) Begin by prying off enough of the finish flooring to expose the nails that hold the underlayment to the subfloor. Pull all exposed nails. Then, use a circular saw with a nail-cutting blade to cut through the underlayment. Remove the underlayment and pull the nails that hold the subfloor to the joists. Mark a centerline on the subfloor just above the joists and cut through the subfloor with a circular saw. Then, use a jigsaw to cut around the toilet mounting flange to free this section of the subfloor and pry up the plywood to expose the plumbing.

The waste lines for a bathtub are often 1 1/2-in.-dia. pipe, but those for a dedicated shower must be 2 in. in diameter. Therefore, the tub drainpipe must be cut and replaced with a new line to service the shower. With a typical PVC waste system, changes are relatively simple. Use a hacksaw to cut the old drain (Photo 6).

Then, install a banded rubber cap to seal off the old pipe (Photo 7). When you make your cut, remove as much of the pipe as possible, but leave enough so that the cap will fit securely on the end.

On our job, the modification of the drain system was pretty straightforward. Because we were also changing the location of the toilet, we just replaced the 90 degree elbow directly under the toilet with a 90 degree elbow that had a side inlet fitting for a 2-in.-dia. pipe.

The techniques for joining plastic pipe, made from either PVC or ABS, are quite simple. Cut the pipe sections to length using a miterbox and hacksaw to ensure square ends. Next, use sandpaper or a file to remove any burrs that remain on the pipe. Then, wipe the ends of the pipe and the inside of the fittings with cleaner (Photo 8). This cleaning solution removes any grease or dirt from the joint surfaces. Then, spread pipe cement on both the pipe end and inside the fitting, making sure to coat all surfaces completely. Push the pipe into the fitting, twisting slightly to spread the cement.

Then, quickly align the parts in their finished position, because the cement begins to set almost immediately (Photo 9).

Next, frame the new end wall that will enclose the shower. Carefully read the directions that come with your shower unit and control valve to determine the location of the studs in this wall. You may have to notch one or more of them to accommodate the valve body and waterlines. Using a level, plumb the new wall in place, then nail it securely to the floor and ceiling joists (Photo 10).

Study the shower installation instructions to establish the exact location of the shower drain. The manufacturer's instructions should also give the height of the drain line above the finished floor. Cut and dry-assemble the pipe and fittings that form the drain and trap (Photo 11). Remember that the standard downward pitch for waste lines from a fixture is 1/16 in. per foot of run.

In order for the shower to drain properly, a vent must be provided for the waste line. It's a simple matter to run the 2-in. vent line up through the end wall (Photo 12). Once the vent pipe enters the attic space, you can either run it straight up through the roof or join it to the main stack inside the attic. We used a wye fitting to join the vent pipe to the side of the drain line. Once the vent assembly is all glued together, be sure to attach it to the framing members in a couple of locations. Perforated steel strapping is perfect for this job.

Installing new supply lines
Next, cut the old water-supply lines for the bathtub and reroute them for the new shower unit. The shower-valve instructions should give the specifications for locating the unit and the copper fittings you'll need for the job. These pieces are joined to copper pipe by soldering, also known as sweating. The techniques for doing this are not difficult, but they do require attention to detail to get the best results. First, it's important that the ends of the tubing be cut perfectly square. While a hacksaw can be used with a miterbox, it's simpler to invest in a decent tubing cutter. A good cutter will cost $10 to $20, and will yield a square cut every time.

Once the tubing is cut to length, use the reamer on the cutter to remove any rough edges on the inside of the pipe (Photo 13). These burrs can prevent the tubing from seating properly in the fitting.

Next, clean the ends of the pipe with a wire cleaning brush (Photo 14), steel wool or emery paper.

Also clean the inside of the fittings with a brush (Photo 15).

Once the mating parts are clean, apply paste soldering flux to the tubing and the fitting, being careful to cover the entire joint surface (Photo 16). The flux prevents oxidation and allows the solder to flow freely into the joint.

Next, assemble the tubing to the fitting and wipe any excess flux from the outside of the joint. Support the assembly with a clamp, if possible, and apply heat from a propane or Mapp gas torch to the fitting, not the tubing. Hold the solder against the joint until it starts to melt (Photo 17). At this point, continue to feed the solder into the joint until you see a band of molten solder around the bottom of the fitting. The solder is pulled into the joint by capillary action.

Next, move the solder to the other end of the fitting and sweat that joint. Then, take a damp rag and wipe away the excess solder. Wiping the joints creates a neat, professional appearance and also reveals potential problems. If a joint seems to need more solder, apply a bit of flux, reheat the parts and add more solder.

Shower installation
Finish installing the shower control valve (Photo 18), and run a pipe up the wall to supply the shower head.

Solder a wing elbow fitting to the end of the shower-head supply line and screw it securely to the wall framing (Photo 19).

Repair the subfloor in the shower area, leaving a hole for the shower drain to protrude. You may have to provide blocking to support the subfloor at the seams. Make sure to nail the subfloor thoroughly to the floor joists.

When the repair is complete, bring the shower unit into the bathroom for assembly. Run a bead of silicone caulk along the flange where the shower sections meet (Photo 20). Be sure to completely encircle the screwholes with silicone to prevent any leaks.

Assemble the shower and use the screws and bolts provided to attach the sections (Photo 21).

Next, lay out the location of the shower control valve on the shower wall, then double-check the shower-valve instructions to ensure that you make the proper size hole. Use a holesaw to bore the hole (Photo 22).

If you are installing a fiberglass shower, like we did, additional support must be provided under the floor of the shower. Otherwise, the floor will flex--though probably never break--when you stand on it. To support the floor, place a 2-in.-deep circle of very dry mortar mix on the subfloor (Photo 23). Keep the mortar about 4 to 5 in. away from the drain opening. Once the mortar is in place, move the shower into its opening, and fit the shower drain. Follow the shower manufacturer's directions for making this drain connection. Keep in mind that you may have to work the unit back and forth a bit to get it to settle properly into the mortar.

Adjust the unit so that it sits level and plumb, then drill pilot holes through the mounting flanges and nail or screw the unit to the framing members (Photo 24). If you are installing a dome top to the unit, run a bead of silicone caulk around the joint surface, position the dome over the shower and attach it with screws.

Next, drill a hole for the shower-head arm through the shower wall and install the arm by threading it into the wing elbow. Use Teflon tape on this threaded joint to prevent leaks. Also use Teflon tape when you thread the shower head onto the arm.

Finishing up
To conceal the area above the shower, build a soffit. A simple ladder-style soffit that extends across the front of the shower and from the lip of the dome to the ceiling will do the job. To build one, just cut 2 x 4 stock for a top and bottom plate to match the width of the opening. Then, cut four short studs that are equal to the height of the opening minus 3 in. for the plates. Nail this "ladder" together and then nail the assembly in place (Photo 25). Attach the dome to the soffit by nailing or screwing through its mounting flange.

Complete the shower-drain assembly by installing the rubber caulking gasket that seals the drain to the waste lines. Push the gasket over the pipe, then install the threaded nut that compresses the gasket. Use the wrench provided with the shower unit and a screwdriver to tighten the trim ring in place (Photo 26). Finally, attach the strainer to the drain body.

Finish up by installing the escutcheon and knob to the shower control valve. Then, turn on the water to the shower and check for leaks in the plumbing before you put up any drywall. Once you are certain that no leaks are present, install water-resistant drywall on the end wall, soffit and any other areas damaged by the construction. Be sure to keep the drywall back from the shower, about 1/8 in., to provide a neat caulk joint. Tape and finish the drywall. Then, prime and paint the whole room when you are done with the other work. Caulk any surfaces that abut the shower with white or clear silicone caulk.

We completed our shower project by installing a shower door. Many different models were vailable. We chose a Showerite unit, model No. 845HR. To install it, we just joined the head jamb to the side jambs and then lifted this assembly into place. Once the jambs were plumbed and leveled in place, we attached the two side jambs to the walls with screws (Photo 27). Our final step was to hang the door.