Laying roof tiles correctly requires following the manufacturer's specification for the specific tile being used: gauge, minimum pitch, fixing requirements, and junction details at ridges, hips, and verges. This guide covers the general principles that apply to most interlocking concrete and clay tile installations.

Preparation: Felt and Battens

Before tiles can be laid, the roof must have a correctly installed underlay of breathable membrane or bituminous felt, and treated timber battens fixed at the correct gauge for the chosen tile. The gauge is the distance between the top of one batten and the top of the next, and determines how far each tile is exposed to the weather. The correct gauge for the specific tile is set by the manufacturer and depends on the roof pitch, the tile's headlap dimension, and the exposure category of the location.

Starting the First Course

The first course at the eaves is typically a double course or uses a purpose-made eaves tile to ensure the correct tilt angle for the first full course above. Fix a tilting batten or eaves board at the foot of the rafter slope to tilt the first course of tiles at the same angle as the courses above, ensuring water runs away from the eaves rather than back toward the fascia.

Setting Out

Before fixing tiles, set out the tile pattern across the roof width. Count how many tiles span the width using a dry run without fixing, and adjust the overlap at each verge to ensure the tile courses finish symmetrically. Mark the gauge and course lines with a chalk line to guide installation.

Fixing the Tiles

Most modern interlocking concrete and clay tiles have nibs that hook over the battens and are fixed with nails or screws at every tile in exposed locations and at alternate tiles in sheltered locations, following BS 5534 and the manufacturer's guidance. Every tile in the top course, at verges, and at any other vulnerable position must be nailed. Use aluminium or stainless steel nails that will not corrode and eventually fail in service.

Work from right to left across the course if the tiles have a side overlap that sheds water from right to left. Maintain consistent side laps and head laps throughout. Cut tiles at verges with an angle grinder or tile cutter, ensuring the cut face is clean and consistent.

Ridge and Hip Tiles

Ridge tiles cap the apex of the roof, covering the junction between the two slopes. They can be mortar-bedded onto the ridge board or fitted with a dry-fix system. Dry-fix ridge systems are recommended for new work as they eliminate mortar failure and reduce maintenance. Hip tiles are fitted along the hip line of the roof in the same way.

Summary

Tiles are laid from the eaves upward at the manufacturer's specified gauge on felt and battens. The first course uses an eaves tile or tilting batten to set the correct angle. Tiles hook onto battens and are nailed in accordance with BS 5534. Ridge and hip tiles are fixed with dry-fix systems or mortar. Always follow the manufacturer's specific installation guide for the tile product being used.