What is sanded vs unsanded grout?
Sanded grout contains silica sand for strength and is used in joints 1/8 inch or wider, while unsanded grout omits sand and is suited for narrow joints under 1/8 inch to avoid cracking.
Grout formulations differ primarily in their sand content, which affects both performance and application. Sanded grout contains fine silica sand mixed into the cement base. The sand particles reinforce the grout, reducing shrinkage as it cures and increasing compressive strength. This makes sanded grout the standard choice for wider grout joints, typically 1/8 inch and larger, where its strength helps prevent cracking under foot traffic and thermal stress.
Unsanded grout omits the silica aggregate, relying on cement, water, and additives alone. Without sand particles to strengthen it, unsanded grout shrinks more during curing. It also has lower compressive strength, which limits its use to narrow joints under 1/8 inch wide. In these tight spaces, unsanded grout flows more easily and fills cleanly without excessive aggregate trying to bridge the gap.
Choosing the right type matters for durability. Using unsanded grout in wide joints leaves the seam prone to cracking and deterioration. Conversely, forcing sanded grout into very narrow joints risks voids, weak coverage, and eventual failure. Tile and stone contractors in Connecticut size grout joints during layout and select the appropriate formulation to match those dimensions, ensuring the finished floor performs well over time.