Proper surface preparation for both residential and commercial tile installations is probably the most important part of the tile installation, yet its often the most overlooked. Even when its recognized, not enough time or resources are allocated to ensure that it is done correctly. Let’s discuss what is required of surfaces prior to the installation of tile and stone.
If you have a cement slab, we need to make sure the surface is relatively clean and dust free. Most residues can be removed with a blade scraper. We use a 4 inch hand scraper along with a stand up floor scraper. For cement residues left over from the slab installation, we sometimes use a cement brick. This is a very coarse stone with the center mounted handle for knocking down high spots on the slab. Within reason, we make the floor as flat as possible. We use at least a 4-foot straight edge or level to check floors for the high and low spots and mark the spots as we are checking the slab. This will come in handy later when we go to lay out the job. If floors have excessive high and low spots, we use a self leveling product. These are cement products that are self leveling and when mixed properly will flow into the low spots. The only other preparation that we can take for a cement floor is an acrylic floor primer. This is a milky liquid that is applied with a brush or roller. It helps to bond the cement floor to the bedding mortar.
If the floor is not cement it will most likely fall in the basic wood floor category. Regardless of the floor covering ” like carpet or vinyl “, most floors built on floor joists” framing members ” have a wood sub-floor. A sub-floor is mostly comprised of two wood layers, while some newer sub-floors only have one 3/4″ inch layer. We need to remove the old floor covering such as old ceramic tiles, vinyl, carpet etc. One exception may be sheet vinyl or vinyl tiles that are applied directly to the sub-floors. Cement board underlayments can be attached to these thin materials without adding significant height to the tile installation. Once the necessary floor coverings are removed, we then remove old glues or cement residue by using a blade scraper. we don’t need to remove every little bit, but enough to make the floor reasonably level. Also, depending on the existing floor covering, we may need to remove old underlayment materials such as a thin 1/4 inch plywood used with many sheet vinyl floors. If were removing old carpet, the carpet tack strips along the perimeters and any staples used to hold the carpet pad in place also need to be removed. We then check the wood sub-floor for damage. In bathrooms, for example, the top layer of the floor could be damaged from a seeping toilet or tub and shower overflows. Overall, the sub-surface must be structurally solid, not pretty just solid. Once we have a solid and flat sub surface, were ready to apply cement board underlayment.
All the basic principles of stud-framed walls are similar to wood floors. Interior residential walls are mostly plaster or 1/2 inch drywall. The main material to be removed from the walls, like in a tub surround, is the existing tile. Many people try to remove the tiles in order to re-install the new tile. This is usually more work than is necessary and results in an irregular surface. Too much glue is left behind and many times the drywall comes off with the tiles leaving holes. Also, in water areas like showers, usually the drywall has been water damage and needs to be replaced anyway. The correct way to properly prep any wet area is to completely remove the drywall and install cement backer board. The best way to demolish a shower or tub surround for remodeling is to score the drywall or plaster along the line appropriate to where the new tile is going and hopefully along a line centered on a framing stud. then we remove the wall surface, tiles and all. This leaves us with a clean framing wall on which to install the new cement backer board, which is the best surface for tile installation. It saves headaches for the both of us. Keep in mind that the new cement board needs to be installed flush with the old surface material. This is relatively simple if were removing 1/2 inch drywall and replacing it with 1/2 inch cement board. But if were removing plaster, which can vary in thickness from 1/2 inch to over 1 inch, some shimming to other framing members will be necessary so that the one half-inch cement board meets the existing surface on the same plane. A key element to this demolition procedure is the appropriate place to score or cut the existing material. we’ll note where the the new tile will fall and then cut between one and two inches inside that line. When the new tile is installed, the last pieces along that line will flow over the seam between the new and old surface alleviating the need for patch and finish work. If we make a cut that corresponds to your new tile, but does not meet to an existing stud, an additional stud will be installed there. Now that weve demolished the existing walls and positioned the framing as needed, were ready to attach cement backer board. Then all we have to do, is provide you with a beautiful tile installation.