Tile Selection Guide: Understanding the Specifications That Matter

Tile Selection and Design

Porcelain, ceramic, natural stone — tile choices are overwhelming until you understand the few specifications that determine whether a tile is appropriate for your application.

The PEI (Porcelain Enamel Institute) rating for ceramic tile ranges from 0 to 5 and measures surface hardness and wear resistance. PEI 1 is for wall use only; PEI 3 is appropriate for residential floor use; PEI 4 to 5 is for commercial and heavy residential applications. Using a PEI 1 tile on a floor guarantees rapid surface wear.

Surface Preparation

Water absorption rating determines whether a tile is appropriate for wet area installation. Impervious tile (less than 0.5% absorption) is required for shower floors and walls where prolonged water contact occurs. Vitreous tile (0.5 to 3% absorption) is appropriate for residential bathroom floors. More porous tile is not suitable for wet areas without consistent sealing.

Rectified vs non-rectified tile: rectified tiles are cut to precise dimensions after firing, producing edges accurate to 0.5 mm. Non-rectified tiles vary by up to 3 mm per tile due to the firing process. Rectified tiles can be installed with grout joints as narrow as 1.5 mm for a seamless appearance; non-rectified tiles require minimum 3 to 4 mm joints to accommodate dimensional variation.

Installation and Grouting

Coefficient of friction (COF) determines slip resistance. Wet area floor tiles should have a minimum COF of 0.60 (DCOF test). Tiles rated below this standard are slip hazards in wet conditions regardless of how visually appealing they are. Always verify wet-surface COF for shower floors, pool surrounds, and bathroom floors.

Shade variation rating (V1 through V4) indicates how much colour variation exists within the same tile batch. V1 tiles are uniform in appearance; V4 tiles have extreme variation that produces a natural, stone-like appearance but requires careful layout planning. High shade variation tiles should be blended from multiple boxes during installation to prevent batch clustering.