How to Replace Cracked Tile Grout in a Tub or Shower

Remove the plumbing trim

• 1

  Remove the tub spout. One type slips over a copper pipe: Loosen the setscrew on the underside with an Allen (hex) wrench and pull off the spout. The other type threads onto an iron pipe: Twist it off either by hand or with groove-joint pliers. Pad the spout first with a rag to avoid marring its finish.

• 2

  Remove the faucet handle(s). Pop off any decorative cap that covers the handle screw with a knife or an awl. Then remove the screw and pull off the handle.

• 3

  Remove the faucet trim. First unscrew or pull off the cylindrical sleeve from the valve. Then unscrew or pull off the flange that covers the hole in the tile. Slide the trim around the shower arm away from the wall.

Remove the grout and clean

• 4
  

  Use a grout saw (some have teeth and others have an abrasive coating on the blade) to remove as much grout from the joint as you can (see A). Work very carefully to avoid scratching the tile.

• 5
  

  Remove the caulk joint between the tile and the tub or shower pan (see How to Seal Wall Joints Around a Tub or Shower).

• 6

  Vacuum with a wand attachment to suck all loose material out of the joints. Sponge on a 50-50 bleach-and-water solution to kill any mildew. Hand-rinse well, and wipe the surface dry with a towel.

Mix and apply the grout

• 7
  

  Mix enough unsanded grout to do one wall at a time. Slowly add water to the powder in a bucket. Mix with a paint-mixing drill attachment until you reach the right consistency. The grout should be just stiff enough so it won't pour out of the container without a push. Wait 10 minutes and remix.

• 8
  

  Spread the grout diagonally across the tile with a rubber float (a grout trowel) held at a 45-degree angle (see B). Press firmly and go over the surface several times to pack the joints. Finish by striking off any excess with the float held at a 90-degree angle.

• 9

  When the grout is dry but still crumbly, use a screwdriver to scrape it out of the joint between the tile and the tub or shower pan, as you will be caulking it.

Clean and seal the surface

• 10

  Before you wet-clean the tile, allow the grout to set up for a few minutes. As soon as you can wipe grout off the surface using a damp (not wet) grout sponge without pulling grout out of the joint, clean until only a light haze of grout remains (see C). Use light, diagonal strokes, and rinse and wring out the sponge often.

• 11

  Clean and shape the joints by wiping parallel to them. Remove the grout until its level is just below the tile's rounded edges. If any voids appear in the process, press in a dab of grout with the float, the sponge or a fingertip (see D), and wait about 10 minutes.

• 12

  Wipe off the grout haze with a soft, dry cotton cloth. Dampen the sponge if needed, or use a green (mild) abrasive pad to scrub off any stubborn spots.

• 13

  Caulk the tub or shower joint (see How to Seal Wall Joints Around a Tub or Shower).

• 14

  After 48 hours, apply a grout sealer, following the instructions on the label.