Cracking

Cracking manifests differently depending on the material involved. On concrete and terracotta tiles, cracks can be caused by impact (foot traffic, falling debris, hail), thermal stress (freeze-thaw cycling), structural movement (settling or rafter deflection), or manufacturing defects. Cracked tiles should be replaced promptly, as even hairline cracks allow water to penetrate the tile body and accelerate further deterioration through freeze-thaw action. On mortar beds and pointing, cracking is almost inevitable over time. Traditional sand-cement mortar is inherently rigid and cannot accommodate the ongoing thermal expansion and contraction of the surrounding tiles. This is why modern roof restoration uses flexible polymer-modified mortars and pointing compounds — they maintain their adhesion and seal through thousands of thermal cycles. In coating systems, cracking indicates either a failure of the coating itself (due to UV degradation or excessive film thickness) or a failure of the substrate beneath (such as a crack in the tile propagating through the coating). Town & Country Roofing addresses all forms of cracking during roof restoration and repair work, from replacing cracked tiles and re-bedding failed mortar to recoating areas where the membrane has cracked.