Nail Sickness
Nail sickness is the corrosion of the steel or iron nails fixing roof tiles or slates, rather than failure of the covering itself. Common on Harrogate's 1960s-70s concrete tile estates and Victorian slate terraces, it causes tiles to slip once the fixings lose their grip, eventually requiring a full re-roof with new fixings.
Flaunching
Flaunching is the sloping mortar cap at the top of a chimney stack that beds the pots and sheds rainwater. On older Harrogate properties it cracks and crumbles with frost exposure, allowing water into the stack. Flaunching is renewed as part of chimney repointing, typically using lime mortar on period masonry.
Torching
Torching is the lime mortar applied to the underside of slates or tiles on older roofs to seal against wind and rain before modern underfelt existed. On Harrogate's 1930s-50s clay tile stock the original torching has usually failed, causing draughts and slippage. It can be re-bedded without a full re-roof in many cases.
Lead Flashing
Lead flashing is the weatherproof metal detailing that seals junctions where a roof meets a wall, chimney, or valley. Specified by code thickness under BS 6915, it is critical on Harrogate's chimney-heavy Victorian and Edwardian properties. Flashing fails when it lifts at the mortar chase or fatigues and cracks under thermal movement.
Pointing
Pointing is the mortar finish between bricks or stones, including on chimney stacks and parapets. On pre-1950 Harrogate properties it must be lime mortar, not cement, because cement is harder than the masonry and causes the brick face to spall when it cracks. Repointing renews failed joints without rebuilding.
GRP (Fibreglass)
GRP, or glass-reinforced plastic, is a rigid fibreglass flat roofing system laid as a continuous seamless laminate. It suits new Harrogate extensions with solid decks, is walkable for maintenance, and lasts 25-30 years with no seams to fail. GRP is one of two systems we recommend over felt, alongside EPDM rubber.
EPDM
EPDM is a synthetic rubber flat roofing membrane laid in large sheets, valued for flexibility and resistance to UV and temperature change. It tolerates deck movement better than GRP, making it suitable for older Harrogate properties, and lasts 20-30 years. Its main maintenance point is seam integrity, which should be checked periodically.
Verge
The verge is the edge of a pitched roof at a gable end, where the covering meets the outer wall. On Harrogate properties verges are traditionally mortar-bedded, though dry-verge systems are now common. Failed verge mortar lets wind under the tiles and is a frequent cause of storm damage on exposed gable elevations.
📞 Still unsure about a term on your quote? Call 01423 203744 for free, no-obligation advice from a local Harrogate roofer.