Compression, all the way down
An arch carries nothing until the ring closes — until then it is a pile of stones arguing with gravity, and timber centering is the referee. We cut the voussoirs on the ground, number them like sheet music, lay from both spring lines, set the keystone last and strike the frame only after the mortar has taken. Nobody has ever talked us into hurrying that last part, and nobody ever will.
Segmental & semicircular
The two working arches of the valley — the flat-cambered segmental over doorways, the full semicircular over entries. Spring lines re-cut, skewbacks dressed, rings closed and pinned, drawn geometry from the first template to the last strike.
Firebrick, graded to the room
Low, moderate, high or super duty — rated by how hot and how often. Moderate-duty carries the Sunday fire; high-duty carries an every-evening Rumford box; super-duty lines the bakery ovens. The grade is written on the drawing you keep.
Crowns, caps & draw
A cast crown sheds water like a roof; a smear of mortar drinks it like a sponge. Crowns cast to pattern, flue tiles relined, caps set, and the draw measured with a gauge while you watch — a chimney is a machine for moving smoke, and we test machines.
The arch rebuild
from $1,950
- Segmental or semicircular, on centering
- Voussoirs cut and numbered, keystone last
- Spring lines re-cut, skewbacks dressed
- Lime repoint of the surrounding field
Quoted off the measured opening after the survey.
The Rumford firebox
from $3,800
- High-duty firebrick for the every-evening fire
- Smoke chamber parged smooth
- Cast crown that sheds water
- Draw gauge-tested with you watching
The grade is chosen by the room, not the budget.
Crown, cap & draw test
from $1,450
- Crown cast to pattern, never smeared
- Flue tile relined where the survey says
- Cap set against the rain and the birds
- The gauge number, written down for you
Often the whole fix, when the flue itself is sound.
The survey
The opening is measured to the millimetre, the mortar chipped and matched, the flue gauged. You keep the drawing and a written number, held sixty days.
The centering
Timber bent to the drawn curve goes up under the ring; the old wall stays standing while the new one is being decided. Raking and cutting carry on around it.
The ring
Voussoirs laid from both spring lines toward the crown, keystone set last, the ring pinned and pointed. Firebrick boxes, where there are any, graded and laid in fireclay.
The strike
Centering comes out only after the mortar has taken — never early, whatever the calendar says. Draw tested, crown cast, thirty years signed into your name.
Thirty years on the ring
If an arch we rebuilt settles, a firebox we laid spalls, or a crown we cast leaks inside thirty years, we return and correct it free. No arch of ours has ever been struck early, and the warranty is priced on that staying true.
Recent work
The ring book
Six jobs from around Gorsevale — arches over doors, a bakery oven, two chimneys that had been “repaired” once too often. Every owner will light the fire or walk you under the ring; ask us for the introduction.
The calendar of a ring
Survey to strike
Day 0
Measure & chip
Opening measured, mortar chipped and matched, flue gauged. The drawing and the written number are yours before we book a start.
Days 1–3
Centering & rake
The timber curve goes up; the surrounding joints are raked by hand to twice their width and vacuumed. Nothing is ground on this crew.
Days 4–8
Cut, lay, close
Voussoirs cut on the ground and laid from both spring lines; the keystone goes in last and the ring is pinned. Fireclay joints in any firebox, struck thin.
Day 9+
Strike & test
The frame comes down only when the mortar has taken. The draw is gauged in front of you, the crown cast, and the thirty-year warranty signed into your name.
Our entry arch had been filled with a concrete lintel in the sixties and we assumed that was that. They cut a proper ring of voussoirs, closed it over a long weekend, and struck the centering on the Monday with half the street watching. It holds, beautifully, and so does the mason’s composure.
They asked how often the fire burns before they said a single price. Every evening, I said — high-duty, they said, and wrote the grade on my drawing. Four winters later the box looks poured rather than laid, and the sitting room draws like a furnace.
The draw test sold me: a gauge, a number, and a mason who explained the number while the wind did its worst. Two chimney firms before them sold me caps. Skewback sold me a working chimney, which turned out to be a different product entirely.
Asked under every ring
When can the centering come out?
Only after the ring has closed and the mortar has taken its initial set — day nine on a typical entry arch, longer in cold weather. Striking early is the one mistake an arch never forgives, and no schedule has ever justified it here.
What firebrick grade do I need?
Duty is rated by how hot and how often. Low-duty suits a decorative gas insert; moderate-duty carries the Sunday fire; high-duty carries an every-evening wood fire and a Rumford box; super-duty is bakery work. We ask how the room is lived in before we pick, because the room is the specification.
Why does my chimney leak when the flue is sound?
Almost always the crown. A smeared mortar crown cracks with the first hard frost and drinks water straight down the flue. A cast crown sheds it — and costs a third of a reline, which is why the survey comes before any recommendation.
Can you match the old brick around the arch?
From two salvage yards and standing stock, approved wet in daylight beside the wall. The ring itself is usually the original stone, re-cut on its beds — we weigh everything before we agree to replace anything.
The guarantee story
Five hundred and twelve rings closed since 1979, and the zero on the left of this page is the one we are proudest of: not one arch struck early, not one ring reopened. The thirty-year warranty is not optimism — it is a ledger entry, and like everything at this yard, you can come and read it yourself.
crown@skewback.example · Gorsevale
Skewback & Crown · Lic. AM-61204 · 9 Springline Yard, Gorsevale · (555) 908-3352 · crown@skewback.example