Roofing Glossary

The progressive corrosion of the iron or steel nails securing roof tiles or slates. On Eastbourne roofs over 70 years old, nail sickness causes multiple tiles to slip at once as the fixings crumble. Once widespread, individual repairs are futile — the roof needs re-nailing or full replacement to BS 5534 standards.

A mechanical system that clamps ridge and hip tiles using screws, unions and a ventilated roll rather than mortar. Dry-fix eliminates the mortar cracking that affects Eastbourne's exposed coastal roofs, needs no maintenance, and complies with BS 5534. It is our standard recommendation for all wind-exposed elevations across East Sussex.

Lead sheet thicknesses used for flashings and weatherproofing. Code 4 (1.8mm) is the domestic minimum; code 5 (2.24mm) is heavier and required near the Eastbourne seafront where salt and thermal movement destroy lighter lead. Correct code selection is the single biggest factor in how long a lead flashing lasts on a coastal roof.

Two modern flat-roof systems. GRP (glass-reinforced plastic) is a hard fibreglass laminate ideal for smaller Eastbourne garages and extensions, lasting 25–50 years. EPDM is a flexible rubber membrane suited to larger areas. Both vastly outlast traditional felt, which is why we no longer install felt flat roofs on East Sussex properties.

The weatherproof barrier — usually lead — sealing the junction between a roof and another surface such as a chimney, wall or valley. Flashing failure is the most common single cause of roof leaks in Eastbourne. Correct flashing is cut and dressed into the masonry, never simply bedded in sealant, which is only ever a temporary repair.

The mortar finish filling the joints in brickwork and around ridge tiles and chimneys. Repointing renews failed mortar. On Eastbourne's pre-1940 and conservation-area properties, lime mortar must be used rather than modern cement, which is too rigid and traps moisture, accelerating decay of the soft historic masonry beneath.

The layers beneath the visible roof covering. Battens are the horizontal timber strips tiles hang from; sarking is the breathable membrane (or older felt) beneath them. During an Eastbourne re-roof, degraded battens and sarking are replaced as standard — laying new tiles over a failed substrate guarantees premature failure regardless of tile quality.

The boards closing off the roof edge. The fascia is the vertical board carrying the guttering; the soffit is the horizontal underside board providing eaves ventilation. Rotted fascia is the hidden cause of most guttering that sags or leaks in Eastbourne — replacing guttering without addressing the fascia behind it is a short-term fix.