Scrape out the old grout with a grout saw or other tool, being careful not to scratch the tiles faces or chip the edges. You may choose to regrout only the filed grout lines for a quick fix, but for more pleasing results and to pleasing results and to prevent color variation in the grout lines, remove the grout around all tiles and regret the entire floor.
Wash h exiled floor with a 1:1 mix of white vinegar and water, paying special attention to the tile joints. Vacuum the floor first to get rid of all debris.
Apply new grout . Prepare grout mix according to the instructions on the package and then pack fresh grout deep into the joints using a rubber grout float. Hold the float at 30 degree angle to the tiled surfaced.
Wipe diagonally across the tiles and grouted joints to remove excess grout and smooth the joints . Seal the grout joints with grout sealer after they have dried for a week so. Note : Sealing the grout joints will help new grout joints will help new grout lines blend with old grout if you are only doing a partial regrouting .
BEFORE you grout or tile you must put placed down Tiling
Tiling Backer Board
Use the tile backer board as the substrate for tile walls in wet areas . Unlike drywall , tile backer won’t break down and cause if water gets behind the tile. The basic types of tile backer are cement board , fiber cement board , and Dens Shield .
Though water cannot damage either cement board or fiber cement board , it can pass through them . To protect the framing members , install a water barrier of 4 milli ply plastic or 15#
building paper behind the backer.
Dens Shield has waterproof acrylic facing that provides the water barrier. It cuts and installs much like drywall , but requires galvanized screws to prevent corrosion and must be sealed with caulk at all untaped joints and penetrations .
Common tile backers are cemented board , fiber cement board and Den Shield . Cement board is made from Portland cement and sand reinforced by an outer layer of fiberglass mesh . Fibercementboard is made similarly, but with a fiber reinforcement integrated throughout the panel . Dens Shield is water resistant gypsum board with a waterproofing acrylic facing .
Staple a water barrier of mili plastic sheeting or 15# building paper over the framing . Overlap seams by several inches , and leave the sheets long at the perimeter .
Cut the cement board in place. Make cut offs and other penetrations by drilling a series of holes through the board , using a small masonry bit. Tap the hole out with a hammer or a scrap of pipe . Cut holes along edges with a jigsaw and carbide grit blade.