The short answer
A roofer's quote or survey can read like another language. This glossary explains the words you are likely to meet, grouped by where they sit on the house: the edges and lines, the layers beneath the covering, the metalwork, and the flat roof and gutter terms. If a word on your paperwork is missing here, ask the roofer to explain it on paper first, and hold off agreeing to the job until it makes sense to you.
The words on a roofer's quote or survey, explained simply and grouped by position on the roof, with links to the pages that go further.
Edges and lines of a pitched roof
Ridge: the highest horizontal line, where the two main slopes meet, finished with ridge tiles. Hip: a sloping line running down an outward corner of a hipped roof. Valley: the sloping channel at an inward corner, which gathers a good deal of water and is lined with lead or special tiles. Verge: the angled edge at a gable end, where the covering stops short of the wall. Eaves: the bottom edge, above the gutter.
Dry ridge and dry verge: fixings that hold ridge or verge pieces down with clips and screws, rather than leaving mortar alone to do the work. Our service page on dry ridge and dry verge goes through them.
Gable: the triangle of brickwork closing off the end of a ridged roof. Rake: another word for the sloping edge along that gable. Parapet: a low wall that rises above the edge of a roof. Pitch: how steep a slope is, in degrees, and every tile has a lowest pitch it is made for. Hipped roof: one that slopes on every side. Abutment: a place where the roof butts up against a taller wall, so metal has to bridge the junction.
Our pitched roofing page covers repairs to every one of these lines.
Layers and fixings under the covering
Battens: narrow timber laths nailed over the rafters, which the tiles hang from. Rafters: the sloping timbers making up the frame. Underlay: a sheet beneath the tiles that catches wind-driven rain, and the modern word for what used to be called felt. Sarking: boarding or membrane stretched over the rafters under the battens, seen on some older roofs. Nibs: small lugs on the back of a tile that hook over the batten.
Tingle: a thin metal strap that holds a slipped slate in place. Dry-fix: clipped and screwed fixing of ridge, hip and verge parts, tested under BS 8612. BS 5534: the published standard that guides slating and tiling work, and expects bedded fittings to have a mechanical fixing as well. It is guidance for good practice rather than a rule of law.
Breather membrane: an underlay that lets water vapour pass out from the loft. Eaves ventilation: the gap at the bottom of the slope that lets air move through a cold roof. Cold roof: insulation laid at ceiling level, with a ventilated void above it.
Our answers on torn roof underlay and broken tile nibs show these parts in use, and the guide on when roof battens need replacing covers the timber.
Metalwork, chimneys and roof windows
Flashing: a strip of lead or other metal sealing the join between roof and brickwork, whether that brickwork is a wall, a stack or the frame of a roof window. Soaker: a small piece of lead tucked under each course of tiles beside a wall or chimney, working with the flashing above it. Apron: the flashing along the lower face of a chimney or window. Lead code: the number showing how thick a sheet of lead is; Code 3 suits soakers only, while Codes 4 and 5 suit flashings, for example.
Flaunching: the sloping mortar collar around the chimney pots that throws water off. Stack: the chimney above the roofline. Pot and cowl: the clay or metal top of a flue and the cap that sits over it.
Roof window: a window set into the slope itself, often called a skylight, or a Velux after one brand. Dormer: a window with its own small roof, standing out from the slope. Cheek: a dormer's side wall, often covered in lead.
See our lead work page, chimney repairs and roof windows and skylights for the work itself.
Flat roof and gutter terms
EPDM: a synthetic rubber sheet laid in a single piece across a flat roof. GRP: glass-reinforced plastic, known as fibreglass, laid wet and left to cure as one continuous skin. Torch-on felt: bitumen felt melted onto the deck with a gas flame. Fall: the gentle slope that lets rain drain off a flat roof. Upstand: membrane turned up against a wall or edge. Warm roof: insulation placed above the deck, keeping the structure warm.
Fascia: the board running along the eaves that holds the gutter. Soffit: the underside board closing the gap between wall and fascia, often with a vent in it. Bargeboard: the board following the edge of a gable. Downpipe: the upright pipe taking water from gutter to drain. Finlock gutter: a concrete gutter section found on some 1950s houses, where leaking joints are the known problem.
Read more on flat roofing and gutters, soffits and fascias. For a general overview of our work, visit roofing across Crawley, and our roof work costs guide uses many of these terms when it talks about prices.
More on this in Roofers in Crawley: the full guide
Two questions about roofing words
What is the difference between felt and underlay?
Felt is the older name for the sheet beneath the tiles, made from bitumen-coated material. Underlay is today's general word and also covers breather membranes. If your paperwork names one or the other, ask which product is meant, and whether it suits the roof and the loft ventilation.
What is the difference between a hip and a ridge?
A ridge is the level line at the summit, where two slopes come together. A hip runs down the slope from the ridge to the eaves, along an outward corner of a hipped roof, and a hipped roof has four or more faces rather than two. Both are normally capped with specially shaped tiles, held down with mortar or dry-fix clips.