Plain-English definitions of the roofing terms Devon homeowners encounter most often. Call 01392 759 295 for a free survey.
This glossary explains the roofing terms Devon homeowners meet most often, from nail sickness to lead codes. Each definition is written in plain English with local relevance. For any term you cannot find, call 01392 759 295 and we will explain it.
The corrosion and failure of the steel nails holding roof tiles or slates in place. Common on Devon homes built between 1950 and 1985, it causes tiles to slip progressively. When more than 30% of a roof slope is affected, re-roofing is usually more economical than continued repair.
Weatherproof sheeting, made from rolled lead, that seals the joints where a roof meets a chimney, wall or valley. Specified by code (thickness) — Code 4 for step and apron flashings, Code 5 for valleys and back gutters. Lead flashing fails through thermal fatigue after 40 to 60 years.
A systematic hand-pressure assessment of tile mobility across a roof plane, used to determine the percentage of fixings that have failed. The survey distinguishes isolated repair sections from widespread failure, and forms the basis of an honest repair-versus-replace recommendation on Devon's ageing estate housing.
A vapour-permeable membrane laid beneath roof tiles that allows moisture to escape from the roof void while keeping rainwater out. Essential in Devon's high-humidity climate to prevent interstitial condensation, which otherwise rots battens and rafters from within. Standard on all correctly specified re-roofing.
The horizontal lead channel behind a chimney stack that collects water running down the slope above and diverts it around the stack. It carries the highest water load of any chimney lead element, is made from Code 5 lead, and is the element most frequently omitted from inadequate repair quotes.
The internal angle where two roof slopes meet, channelling concentrated water flow toward the eaves. Valleys carry a disproportionate share of a roof's rainfall load and fail through lead fatigue, debris blockage or under-specification. In Devon's high rainfall, valley condition is a critical element of any roof survey.
Glass Reinforced Plastic, or fibreglass, a liquid-applied flat roofing system that cures to a seamless rigid sheet. It provides 25 to 30 years of service in Devon's climate, with no joints for rainwater to exploit. GRP is the preferred choice for standard Devon extensions under 50 square metres.
A traditional mortar made with lime rather than cement, used for ridge bedding and chimney pointing on pre-1900 masonry. Its flexibility and breathability suit period buildings; cement mortar, by contrast, causes spalling and traps moisture. Lime mortar is mandatory on conservation area and listed Devon properties.
Need a term explained that is not here? Call our team on 01392 759 295 — free advice, no obligation.
Free survey across Exeter and Devon. No call-out fee. Call 01392 759 295.
01392 759 295