Grout selection on multifamily projects is a specification decision that most GCs delegate entirely to the tile sub, which is appropriate only if the tile sub is managing the decision with awareness of the use environment, the tile format, the maintenance expectations of the property operator, and the aesthetic intent of the project. A tile sub who defaults to their standard production grout selection without considering these factors may specify a grout that stains easily in a high-use residential wet area or a grout that does not achieve the specified joint width for the tile format being installed.
Understanding the grout selection decision allows GCs to ask the right questions during the tile submittal review and to confirm that the specification is appropriate for the project before installation begins.
Grout types and their applications
Unsanded grout is specified for grout joints 1/8 inch or smaller. It is used with rectified tile, tile with precise and consistent edge dimensions, which can be installed with very tight joints. Unsanded grout has a smooth, fine-grained consistency that is appropriate for narrow joints where the filler material must fit without cracking. Using unsanded grout in joints wider than 1/8 inch causes the grout to shrink and crack as it dries, producing an installation that will require regrout within a few years.
Sanded grout is specified for grout joints 1/8 inch or wider. The sand aggregate in the mixture prevents shrinkage cracking in wider joints and provides structural support for the grout column. Sanded grout is the most common specification in multifamily wet areas where the tile format and installation method produce joint widths above 1/8 inch. The sand in the mixture can scratch polished tile surfaces if the tiles are not cleaned promptly after installation, before the grout has fully cured.
Epoxy grout is specified in commercial applications and in high-stain-risk residential areas where the porosity and stain susceptibility of standard cement grout is not acceptable. Epoxy grout is non-porous, highly stain-resistant, chemically resistant, and does not require sealing. It is more expensive and more difficult to install than cement grout, requiring precise application timing and thorough cleanup before the material sets. Epoxy grout is appropriate for commercial kitchen areas, pool facilities, heavily used fitness center restrooms, and any application where cleaning chemical resistance or grout staining is a persistent maintenance issue.
Color selection for multifamily applications
Grout color significantly affects the long-term appearance of a tiled surface. Light-colored grout in high-traffic wet areas shows staining from use and cleaning products that dark-colored grout does not show. Dark-colored grout in light tile applications hides staining but can visually dominate the tile pattern in a way that the designer may not intend.
For multifamily residential wet areas, specifying a mid-tone grout in the gray range, a warm medium gray or a cool charcoal, balances stain resistance with visual integration with the tile. Light beige and white grout in bathroom shower areas is a maintenance liability: it discolors from minerals in the water, cleaning products, and soap residue within the first year of occupancy, producing a visible deterioration that the operator receives complaints about.
The grout color specification should be confirmed in the tile installation submittal before installation begins. Specifying “match tile” as the grout color instruction to the tile sub is not a color specification. It is an instruction that will be interpreted differently by different tile crews and may produce a result that does not match the design intent.
Sealers and sealing requirements
Standard cement-based grout, both sanded and unsanded, is porous and requires sealing to resist staining. In multifamily residential applications, the tile sub should apply a penetrating grout sealer after the grout has cured and before the unit is occupied. Sealing is not a final inspection item that happens at move-in; it is part of the tile installation scope.
Confirm with the tile sub that grout sealing is included in their scope and that it will be performed after the grout has fully cured, typically 48 to 72 hours after grouting, before the unit turnover walk.
Epoxy grout does not require sealing. If the specification calls for epoxy grout, confirm that the tile sub is not applying sealer to the epoxy, as some sealers are not compatible with epoxy grout surfaces.
Grout joint width and tile format coordination
The grout joint width specified for a tile installation must be appropriate for the specific tile being installed. Rectified tile can be installed with joints as small as 1/16 inch with unsanded grout. Non-rectified tile with dimensional variation requires wider joints to accommodate that variation, typically 3/16 to 1/4 inch for most floor tile applications. Installing non-rectified tile with a tight joint produces lippage at the joint edges where tile dimensions vary.
Confirm in the tile installation submittal that the specified grout joint width is appropriate for the specific tile product being installed. The submittal should identify the tile manufacturer and product, the tile format, whether the tile is rectified or non-rectified, and the specified grout joint width and grout product.
How Innergy handles grout specification on tile projects
On Innergy tile installations, the grout product, color, and joint width are specified and submitted for GC review before installation begins. We specify grout color appropriate for the use environment and maintenance expectations of the property, not defaulting to standard production color selections. Sealers are applied after full cure as part of the tile installation scope. For tile installation as a standalone scope or as part of a full seven-division package in TX, WA, OR, CO, UT, or NM, contact us and we respond within one business day.
Grout specification should be confirmed in the tile installation submittal before installation begins. The submittal should identify the grout manufacturer and product name, the grout type (sanded, unsanded, or epoxy), the specified color name and code, and the specified grout joint width for each tile application. A submittal that specifies only the tile without addressing grout leaves the most maintenance-sensitive component of the tile installation unspecified.