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Is it ok to Install Ceramic Tile or Stone Tile on a Sand Base?
QUESTION
we hired a local contractor to install a hardscape project for us. They installed approximately 400 square feet of 24 x 24 Landmark Ceramics porcelain tile. These were to be installed in a 4-foot-wide walkway. The contractor abandoned the project before it was finished. We have since found out the nothing was installed properly. This was to be a sand set installation. The wrong type and size of spacers were used, the substrate was inconsistent, not compacted properly and not even present in some locations. The Sure Bond Poly Sweep joint sand failed, and the Snap Track containment system was improperly installed and, in some areas, not at all. The tile walkway started to become loose almost immediately. Is it proper to sand set tiles?ANSWER
Sand-setting tiles is not considered the best way to install ceramic or natural stone tiles, although it is done and has been done for many years and is normally less expensive than pouring a concrete slab and bonding the tiles to it. It is common for installing thick concrete interlocking pavers. It is much more difficult to install the porcelain tiles in a sand-set method because they are so thin. You have to use at least the 3/4" (2cm) thick porcelain tiles. Historically they would only install 1.25" (3cm) thick natural stone tiles or thicker in this method so they are less prone to damage.The Tile Council of North America (TCNA) is working on developing an installation method for 2cm thick porcelain tiles, but there is not standard at this time. The Natural Stone Institute does provide some information on sand-set stone installations.
It is the 2"+ concrete pavers that provide the best information for concrete paver installations. The Interlocking Concrete Pavement Institute (ICPI) is a good source for installing concrete pavers, but they don't necessarily apply to ceramic tile or natural stone. But their installation methodology would be a good guide for establishing a good base for a sand-set tile installation.
2cm Porcelain tile should never be recommended for a sand-set installation method that is subjected to vehicle traffic, because it is too thin and you can't achieve an interlock condition.
The proper way to install a sand-set installation base is to first grade the ground to the appropriate slope for the intended design and to make sure it will facilitate drainage away from the house to a drain. Compact the natural soil with a compacter machine. Then apply a gravel road base material that is crashed rock and sand that is compatible. In thinner layers put the gravel down and compact it with a compactor and building it up to the desired thickness. Use a metal screed to screed the base surface to be within the intended plane in a uniform manner. Residential foot traffic should be at least 4" thick. For commercial vehicle traffic it should be at least 8" thick more more. The finish surface has to be flat and within the plane of the sloped surface
Install a 1/2" of masonry sand over the compacted base and compact it with a compactor. Add another 1/2" of sand loosely and beat the tile or paver into place. Now compact the tile into place with a compactor so that the surface is flat and within the intended sloped plane. you can't have any low spots where water can collect. Fill the tile or paver joints with a masonry sand or a polymeric sand to hole the tile in place. It is critical that you pour a concrete footing along the perimeter of the sand-set installation that is about the thickness of the sand base and the tile or paver on top of it. Normally you pour the concrete to the height of the top of the sand base and the adhere the tile or paver to the concrete footing so it constrains the tile to prevent it from pushing out when it is subjected to foot or vehicle traffic.
For a 2cm porcelain tile to work well on this application, everything has to be perfect. You cannot have any voids under the tile or it will break.
4 thoughts on “Is it ok to Install Ceramic Tile or Stone Tile on a Sand Base?”
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I have a similar situation. Could I use pure silicone caulk in the joints that have shown erosion and feel hopeful that that might stabilize the tile joints. I know it is not the best but could it help until I am able to have a new floor installed.
Sand-set installation will tend to move to some degree depending on how they were installed and what kind of constraining perimeter is in place to prevent lateral movement.
Using a silicone or other sealant to caulk the joints would not be recommended and would not likely hold up well. Typically a polymeric sand is installed in the joints that has a polymer in the mix. After you vibrate the polymeric sand into the joints you slight wet it down that activates the polymer and helps prevent the sand from getting washed or blown out. It isn’t perfect, so expect there to be some annual maintenance to replace the polymer sand where needed.
Hi, our home tile is white and looks clean (it is mopped regularly). However, I could mop every day and the water would still come out dark grey almost black and there’s always grainy/sand residue. This is not newly installed tile. I am wondering if the tile or the grout itself could be releasing dirt? Any thoughts?
Sounds like it is likely the cementitious grout that is bleeding the color pigment from the grout and the sand aggregate in the grout is degrading. Cementitious grouts should not bleed color, but some manufacturers of grout have this deficiency. The grout might be too soft and subject to degrading. In terms of what can you do about it, there is not absolute solution other than remove and replace the grout. After the grout is clean and dry, you could seal it with a grout sealer that might stabilize it to some degree, but you will have to experiment on small out of the way areas to see what is working before you apply it to the entire area.