Can I tile over other types of flooring?
Guidelines for tiling over other surfacing materials are covered in the Renovation section of the TCNA Handbook in detail TR711. When tiling over other surfaces, always make sure to check with the mortar and grout manufacturers to find the right material for bonding to the surface in question.
The manufacturer’s of tile cement (thinset) have developed specialty formulations for setting tile that are designed to bond well to specific surfaces. However, as with all tile installations, the entire substrate below the tile is important – not only the layer to which the tile is bonded.
Can I tile over laminate?
The manufacturers’ of tile cement (thinset) have developed a specialty thinset for setting tile that bonds well to resin-based laminates (often called plastic laminates). However, as with all tile installations, the entire substrate below the tile is important – not only the layer to which the tile is bonded.
To safely tile over laminates, the following generally should be true:
- The laminate must be clean and free of wax or other bond breakers.
- The laminate must be well attached.
- The substrate below the laminate must meet the L/360 specification.
- For counters, the substrate should be more substantial than just 3/4″ plywood with a layer of laminate. Rather it must meet normal tile installation specs before you should consider applying tile directly to the laminate.
- Mechanical abrasion of the laminate may be necessary to insure a good bond.
For more information regarding suitable countertop construction (for use under tile), please refer to the TCNA Handbook, details C511, C512, and C513.
Can I tile over terrazzo?
There are many kinds of terrazzo floors; some are made with cement while others use epoxy and other resins. Often the floor is coated with acrylic or wax floor finishes after the initial polishing. Many surface coatings will act as bond breakers and must be fully removed. Further, the highly polished surface of the terrazzo can present bonding problems and may need to be mechanically abraded for good adhesion (note: mechanically abrading a floor can create hazardous dusts depending on the surface being abraded – proper protective measures should be taken before undertaking such an operation).
The tile system chosen for tiling over the terrazzo must take into account the building structure and design as generally indicated in the TCNA Handbook (e.g. the methods for tiling a suspended slab are different from those for tiling concrete on grade).
The thinset chosen, if a thinset method is used, must be compatible with the type of terrazzo AND recommended by the thinset manufacturer for that purpose. Typically, epoxy thinsets are used on epoxy terrazzo and cementitious thinsets are used on cement-based terrazzo.
In general, it is best to discuss the exact application with the grout and mortar company you normally use. Inspection of the job site may be necessary as well. An anti-fracture membrane may be needed where there are cracks in the terrazzo or any potential separation between the terrazzo and the metal divider strips.
Can I tile over vinyl?
Most manufacturers’ of tile cement (thinset) have developed a specialty thinset for setting tile that bonds well to sheet vinyl. However, as with all tile installations, the entire subfloor below the tile is important – not only the layer to which the tile is bonded.
To tile over sheet vinyl, the following is generally recommended by most mortar manufacturers:
- The sheet vinyl must be clean and free of wax or other bond breakers.
- The sheet vinyl must be single layer only and well attached.
- It should not be perimeter glued (it often is!) and it should not have a cushion or foam back.
- The subfloor below the sheet vinyl must deflect less than the industry standard L/360 deflection criteria.
In all cases, we do not recommend straying from manufacturer’s recommendations. You must check with the mortar manufacturer for their specific installation and product advice.
Can I bond tile to the black “cutback” residue left when old vinyl tiles were removed?
Whether or not a person should ever set thinset and tile to the glue left behind when non-asbestos vinyl tile was removed depends on the type of glue left behind.
Physically removing all coatings is the most reliable way to make sure you have an appropriate surface to which to bond tile but the old asphaltic (black) adhesives (often called “cut-back”) can be very difficult to remove unless you use shot-blasting equipment. Fortunately, most grout and mortar manufacturers make a thinset which will bond to “cut back” adhesive.
Typically, the “cut back” should be scraped smooth so the tile is not sitting on ridges of adhesive – although it does not have to be absolutely flat. Note, not all thinsets will bond to cutback so it is important to make sure the thinset used is made for that purpose.
Also, the adhesive must be true “cut back.” That means it was made from asphaltic material, is not water sensitive, and will not soften when exposed to water. There are also black-colored latex-based vinyl adhesives that will not hold up under ceramic tile if they get wet.
If the adhesive is softened by water, then it should be removed by shot-blasting. Generally, chemical removal is not a good idea because the solvents used to remove the adhesive can drive “bond-breakers” deeper into the concrete.
It should also be remembered that the removal of asbestos-based resilient tile requires very different handling and the comments above do not apply to such installations.
Can I set tile on the residue of carpet adhesive?
The adhesive (often called carpet mastic) used under most glue-down carpet is usually water-soluble and tends to prevent thinset from properly adhering. Should the tile get wet, the mastic may soften, negatively affecting the bond of the tile to the substrate. Thinset manufacturers recommend removing all traces of carpet adhesive if you plan to bond the tile directly to a surface that previously had glue-down carpeting.