[Note: Some of the tasks below require specialized knowledge and skill in plumbing and electrical installation. If you do not possess this, you should contact a licensed plumber and electrician.]

by George Taniwaki

The first floor of our house has a small powder room off the main hall (about 7’ x 3-1/2’, Fig 1). The previous homeowner remodeled this room a few years before we bought the house so it was in good condition (Fig 2). When we began our home remodeling project, we did not plan to do any work on the powder room.


Figures 1 and 2. Plan view of first floor bathroom (left); and view before remodel

That changed as soon as we began demolition work for the laundry room upstairs directly above the powder room (see Dec 2011 blog post). We discovered that one of the joists between the floors needed to be reinforced and the subfloor replaced. To do that, we had to remove the drywall on the ceiling of the powder room to slide in the new joist. This pretty much ruined the room, forcing a remodel.

The work plan

Once we knew that the powder room needed to be remodeled, we had to decide what work to do. Our plan was to have smooth painted walls rather than textured walls or wallpaper. We also want all the metal surfaces to be antique bronze. The following work would be required:

  1. Demolition
  2. Rough in plumbing, venting, and electrical
  3. Add sound insulation
  4. Add blocking for fixtures
  5. Install new ceiling and walls
  6. Tile the floor and baseboard
  7. Install door casing and door threshold
  8. Install lighting, sink, toilet, and fixtures

The following sections describe how to do all this.


Turn off the power to the bathroom. Remember the outlets and lights may be on different circuits. Remove all the old fixtures and drywall. Save any fixtures that will be reused.

Shut off the water to the sink and toilet. Remove the toilet tank lid. Flush the toilet and keep the flapper valve open to drain the tank. Pour a bucket of water into the toilet bowl to siphon out the remaining water. Disconnect the water line and check for slow leaks. Plug the shut off valve if necessary. Remove the bolts holding the toilet to the drain flange. Carefully lift the toilet and remove the wax ring. Place the toilet in a large garbage bag and set aside. Cover the toilet drain with aluminum foil to seal it while you are working (Fig 13).

Disconnect the water lines and drain lines from the sink. Check for leaks. Disconnect the sink from the wall and set aside. If necessary, remove the sink pedestal. To do this, use a reciprocating saw. Slide a blade between the floor and the pedestal and cut through the adhesive (Fig 3). This may ruin the floor tiles and they may need to be replaced.


Figure 3. Removing the sink pedestal

Rough in plumbing, venting, and electrical

The bathroom originally had 5″ long chrome nipples on the water supply line. Replace them with shorter nipples painted antique bronze to match the new faucet and fixtures. Also replace the leaky shut off valves with new quarter-turn ball valves.

The original powder room had an exhaust fan, as is required by building code. It was installed in the wall. A duct ran in the basement joist space and out the back of the house. It was wired to the same circuit and switch as the light fixture.

While working on the ductwork for the furnace in the basement (see XXX 2010 blog post), I discovered that the vent duct was made of 4” flex hose rather than rigid pipe, meaning it couldn’t carry much air. Further, the flex hose ran inside the return air duct for the furnace, reducing the volume of air available to the furnace.

To replace the fan, remove the old fan and vent hose. Repair the hole in the side of the house. Buy a replacement exhaust fan and mount it in the joist space above the ceiling. It is actually preferable to use a less expensive and noisier fan since that will enhances privacy. Vent the fan to the rear of the house using 4” rigid galvanized pipe. Tape all seams. Cap the vent with a flap to keep out cold air and birds (Fig 4). Insulate the opening with spray foam. Paint the cap to match the house.

Connect the new fan to the switch. You may need to splice the electrical line and add a junction box.

One more bit of electrical work, install a light fixture box for a wall sconce. The box should be high enough to fit the mirror and sink below it. But it should not be so high that the light fixture looks crowded against the ceiling.

Add sound insulation

The original powder room had no sound attenuation.

Wrap all the ABS drain pipes and vent lines with mass loaded vinyl (MLV) at 1 lb/sq ft to reduce the noise of water draining from the laundry room on the floor above. Fill the space between studs with R-15 glass fiber insulation to reduce sound transmission and increase privacy (Fig 5).

Add blocking for fixtures

The original framing did not include any blocking. The pedestal sink was screwed into the wainscoting, which did not provide adequate support. The sink would wobble.

Securely nail or screw 2″x4″ lumber into the studs as blocking behind the sink (Fig 6), mirror, towel bar, toilet paper holder, and any other fixtures. Also add blocking around the perimeter of the floor to support the tiles on the base molding.


Figures 4 to 6. Vent cap for new exhaust; insulation for sound control; blocking to support pedestal sink

Install new ceiling and walls

The original walls and ceiling in the powder room were standard 5/8″ drywall covered with knockdown texture plaster. During a remodel by the previous homeowner, the textured walls were  covered with wallpaper, which looked very odd.

To reduce the chance of water damage, cover the studs with moisture resistant drywall (green board, Fig 7). Use 5/8″ thick drywall for fire protection (required by building code for ceilings) and noise suppression. Use ceramic coated screws to avoid rust spots.

Tape the drywall using glass fiber tape . Cut the tape to a 90° point (Fig 8) when fitting the corners so that the tape does not overlap (Fig 9). Apply three coats of mud, sanding between coats to create a smooth finish (Fig 10).

Paint the ceiling, exhaust fan cover, and ceiling wall plate a dark accent color. Paint the walls to match the walls in all the other rooms (Fig 11).



Figures 7 to 11. Water resistant drywall installed; Glass fiber tape cut and applied; three coats of mud applied; ceiling and walls painted

Tile the floor and baseboard

The subfloor in the powder room is covered with 3/4″ particle board underlayment followed by 12” square ceramic tiles. When laying 3/4″ tongue-and-groove oak flooring in the hall we had to chisel out 3 tiles in the doorway. They will need to be replaced. Some of the tiles near the wall were too small (Fig 12) and will leave a visible gap next to the tile baseboard. The tiles around the toilet flange were cut too loose and leave a visible gap around the toilet (Fig 13). These tiles will also need to be replaced. Make sure you have enough spare tiles to do this. Otherwise, remove all the tile and buy enough new tile to complete the project.

Remove the unwanted tiles using a hammer and cold chisel. Be careful not to chip the tiles you want to keep. Remove the mortar or adhesive using a putty knife or oscillating saw with scraper attachment. Remove grout from between the remaining tiles using an oscillating saw with grout knife attachment (Fig 14). Don’t try removing the grout using a handheld grout knife. It is too much work. If you don’t own an oscillating saw, it is better to just remove all the tile and start over.

Decide whether you want the factory edge or the field cut edge facing up on the tile for the base molding and ensure you cut the tiles on the correct sides. (For this project the factory edge is facing up.) Remember to leave room for the door casing (see next section). Using a tile saw, make all the straight cuts for the new tiles (Fig 15). Spray paint the top edge of the tiles for the base molding to match the grout color (Fig 16).




Figures 12 to 16. Tiles next to wall are too small and need to be replaced; Tiles around toilet flange are misshapen and need to be replaced; Removing the old grout; Making the straight cuts for the tiles using a tile saw; Painting the edges of the baseboard tile to match the grout color

To tile around the toilet drain, make a paper template (Fig 17). Trace the template onto the tiles using a crayon or permanent marker and add 1/4″ extra to allow room for grout (Fig 18). Notice that the right side tile contains more than half a circle, which would be difficult to cut. Since this tile is mostly hidden under the toilet, we can cut about half of the circle out. This line is also marked on the tile. Cut a series of parallel grooves into the tile using a tile saw. Cut away the unwanted tile using a pair of tile nibblers (Fig 19).

Add flange extenders to the toilet drain to ensure the flange will be about 1/4″ above the finished level of the tile. Use plenty of silicone sealant to ensure a gap free (and thus odor free) connection. Use mortar or tile adhesive to attach all the tiles to the floor and walls. Wait a day and then grout the tile. Wait another two days and seal the grout (Fig 20).



Figures 17 to 20. Making a template for the toilet flange; Tracing the template onto the tiles; Making curved cuts using a tile saw and tile nibbler; The completed toilet flange

Install door casing and door threshold

The door to the powder room is fir and the exterior casing is made from stained hemlock (see Oct 2012 blog post on how to make this). However, I think stained wood looks too formal on the inside of the powder room, so I made the interior casing from 3-1/2″ wide primed pine.

Paint the casing with 3 coats gloss enamel to match the other trim in the house. Attach the casing to the studs using finish nails. Fill the nail holes, sand, and touch up paint (Fig 21).

To connect the tile floor in the powder room to the oak floor in the hall, insert an oak threshold. Stain it to match the floor and apply three coats of varnish. Use construction adhesive to attach it to the subfloor and use clear silicone sealant to attach it to the oak floor and tile (Fig 21).


Figure 21. Detail of door casing meeting tile floor and tile baseboard

Install lighting, sink, toilet, and fixtures

Install the fixtures from the top of the room down, starting with the cover for the exhaust fan and junction box.

Install the light fixture following the manufacturer’s instructions.

Install the mirror to a height that matches the light fixture and is centered beneath the fixture (not centered on the wall).

Install the towel bar at arm height. If the towel bar is made of thin gauge metal, reduce the rattle it makes by first filling it with foam insulation  (Fig 22). After the foam cures, cut off most of the excess, leaving about 1/4″ plug sticking out. When you insert the rod, it will not rattle and will sound solid when you tap on it.

Install the sink centered beneath the light fixture and mirror (not centered on the wall). First mark the pedestal with pencil or tape indicating the exact front, back, and sides. Place the pedestal and sink in position. Using masking tape and pencil, mark the floor with the alignment points for the front, back, and sides of the pedestal (Fig 23).

Mark the mounting holes for the sink on the wall.

Remove the sink and pedestal and set aside.

Drill holes in the wall and screw in 5/16″ anchor bolts for the sink. Add neoprene washers to the anchor bolts.

Attach the pedestal to the floor using clear silicone sealant. Add shims to ensure it is plumb. After the sealant to cures, apply foam tape to the top of the pedestal and slide the sink into place and onto the anchor bolts. Add more foam tape as needed to ensure the sink is level.

Slide on another neoprene washer, a steel washer and nut on each anchor bolt and tighten until the sink does not wobble.

Replace the faucet and pop-up stopper, with a new antique bronze set. Replace all washers on the p-trap and drain pipe and assemble the drain line. Note that there are two types of washers. Use the plastic and tapered kind for threaded connections. Use the rubber and square kind for slip fit connections (Fig 24). Sand the p-trap and drain pipe and apply two coats of antique bronze spray paint (Fig 25). Replace or paint the shut off valves, escutcheons, and water supply lines, if necessary. Turn on the water, fill the sink, and test for leaks.

Install the toilet paper holder and any other remaining fixtures.

Install the toilet using a new wax ring and hold down bolts. Replace or paint the tank lever, if necessary. Replace or paint the shut off valve, escutcheon, and water supply line, if necessary. Turn on the water and use a dye kit to test the toilet for leaks. (You can get the kits free at most hardware stores.) Replace the flapper valve if there is even a small leak.

You are done (Fig 26a).



Figures 22 to 25. Fill a hollow towel bar with foam; Align the pedestal to the light fixture and mirror; The two kinds of washers for the drain, threaded on left, slip-fit on right; Paint the water supply lines, escutcheons, and drain line to match the faucet color

For such a small room, there certainly was a lot of work involved in the remodel. And given the amount of work I did, there doesn’t seem to be a lot of change. Oh well.


Figure 26a and 26b. The finished powder room and the original.

For more ideas on home remodeling projects see the Home Remodeling Guide.

All photos by George Taniwaki, drawing in Figure 1 courtesy of Soderstrom Architects