The short answer
Roofing words describe where a part sits and what it does. The ridge is the top line, hips and valleys are the sloping joins, the verge is the gable edge, and flashings and soakers are the lead or metal that seals joins to walls. Battens carry the tiles, underlay sits beneath them, and EPDM and GRP are flat roof coverings. Each one is explained below.
The shape of the roof: ridge, hip, valley, verge and eaves
Ridge: the level line at the very top of the roof, capped by ridge tiles. On a Victorian terrace in the Railway Village it runs the whole length of the terrace house from one party wall to the other.
Hip: the sloping external join between two slopes that meet at a corner. A hipped bungalow or a 1930s semi has one at each end instead of a gable wall.
Valley: the internal fold between two slopes. Rain from both runs into it, so it needs a lining of lead or a preformed GRP trough. A rear extension often creates one.
Swept valley: a valley where specially cut slates curve round the join, instead of meeting in a hard mitre. It belongs to traditional stone roofs on Cotswold-edge cottages.
Verge: the sloping rim of the roof at the gable end of a house. On a semi it is the line above the party wall, finished in mortar, a bargeboard or a dry-fix trim.
Eaves: the bottom of the slope, where the roof overhangs the wall and the gutter hangs.
Joins and weatherproofing: flashing, soaker, flaunching and back gutter
Flashing: a strip of lead or other metal that seals the junction between roof and wall, chimney or window. Step flashing follows a sloping wall in a series of steps.
Soaker: a small piece of lead, one per course of tiles, that bends beneath the covering and turns up the wall. Soakers are usual at dormer cheeks and wherever a roof butts against a higher wall.
Flaunching: the sloping mortar crown on a chimney stack that beds the pots in place and throws water clear. Cracks in it let water in, and our page on chimney flaunching covers the signs.
Back gutter: a lead channel behind a chimney that carries water round the stack. Our page on the chimney back gutter shows how it fails.
Abutment: any place where a roof slope runs up against a wall.
Tingle: a small strip of lead or metal that props the edge of a slate or lead sheet, hidden from view and put in to stop it lifting.
Cheeks: the side walls of a dormer, usually tiled or clad and sealed with soakers.
What sits under the covering: rafters, battens, underlay and sarking
Rafters: the sloping timbers that form the roof structure, the ones you see from inside the loft.
Battens: thin timber strips nailed across the rafters, which the tiles or slates hang from. Their spacing depends on the size of the tile and the pitch of the roof.
Underlay: a sheet laid across the rafters under the battens, acting as a back-up barrier to wind-blown rain and snow. Older roofs may have bitumen felt or nothing at all.
Sarking: boards or a continuous membrane laid under the battens, adding another layer below the covering. You are likelier to meet it on a slate or stone roof than a plain tiled one.
Pitch: how steep the roof is, given in degrees. Every covering has a minimum pitch on its own data sheet, so the slope limits what can be laid.
Diminishing courses: rows of stone or slate that get smaller towards the ridge, as on traditional Cotswold roofs. The biggest slates sit at the eaves.
Underlay lap: the overlap between sheets of membrane, which has to run the right way so that water drains onto the sheet below.
Materials: lead codes, EPDM, GRP, felt and dry-fix
Lead code: a number from 3 to 8 showing the thickness of rolled lead sheet. Code 4 is the usual pick for general flashing, and Code 5 is often used where extra strength is wanted. Higher codes are thicker and heavier.
EPDM: a synthetic rubber sheet used on flat roofs, laid in one piece. It suits garage roofs and extensions where a single large sheet fits. National sources suggest 20 to 30 years or more.
GRP: glass-reinforced plastic, often just called fibreglass, laid wet over a deck and finished with a topcoat. Dormer flats and small balconies often use it.
Torch-on felt: layers of bitumen felt heated to bond them to the deck. It costs less than the alternatives but usually has a shorter life.
Dry-fix: a mechanical system that holds ridge, hip and verge tiles with clips and fixings rather than mortar alone. BS 8612:2018 is the specification for these systems.
Fascia and soffit: the board that holds the gutter, and the one that closes the underside of the overhang. Older houses have timber, newer ones uPVC.
Using the words on a quote
Knowing these terms makes a written quote easier to read. If it says "renew soakers and flashings to the rear addition", you now know it means the lead that seals the join between that roof and the wall. If it says "dry-fix ridge", it means a clipped system, not just mortar. A word you cannot place is worth a question, and a roofer should be glad to explain it.
For more on what a roof job costs, see our roofing costs guide. If you are selling, should I fix my roof before selling shows which of these parts a buyer's surveyor tends to question. And before anyone goes up to look at a ridge or verge, read whether roofing is a dangerous job, because this is work for people with the right equipment, not a Saturday on a ladder. Our homepage lists the jobs we take on.