Newmarket Roofers carries out chimney rebuilds in Haverhill, handling every stage from the first inspection on scaffold to clearing up when the job is done.
If you have never had chimney work done before, the process can feel opaque. Scaffolding goes up, things happen at height, and eventually the scaffold comes down and the chimney looks different. This page walks through every stage of a chimney rebuild in the order it happens, so you know what to expect and what questions to ask at each point.
Before any price can be given for a chimney rebuild, the stack needs to be properly looked at. Viewing from the ground with binoculars gives a rough picture - you can spot a leaning stack, missing mortar and loose pots from the pavement. But it does not tell you how far down the damage extends, whether the flashing is correctly bedded, or how sound the lower courses are.
A proper assessment of a chimney stack that needs rebuilding should be done from scaffold or at minimum from the roof slope. Some roofers price from the ground and then discover on the day that the work scope is larger than expected. It is reasonable to ask any roofer how they have assessed the stack and what they are basing their price on before you agree to anything.
Once the job is agreed, scaffold goes up around the chimney stack before any work begins. For a chimney rebuild, the scaffold needs to provide a working platform at or just above roof level, with full boarding around the stack and a means of raising materials and lowering rubble safely. A single tower leaning against a wall is not adequate for a rebuild job.
The scaffold will typically be up for the duration of the job and for a short period before and after. On most residential chimney rebuilds the scaffold itself is a significant part of the overall cost - it is not a shortcut worth taking.
Once the scaffold is up and the working platform is secure, the roofer starts at the top and works down. The pot comes off first - carefully, because a terracotta pot being dropped onto a tiled roof below will cause immediate additional damage. The flaunching around the pot base is broken out next.
The lead flashing at the base of the stack is carefully removed and set aside. If it is in good condition and correctly specified - Code 4 lead, properly dressed into the joints - it may be reused. If it is cracked, thin, or has been sealed with mastic at some point, it should be replaced.
The brickwork is then taken down course by course. Each course is assessed as it is removed. The roofer is looking for courses that are still firmly bonded with sound mortar - these are the ones to stop at. A saturated or crumbling course that looks intact from a distance often crumbles when the course above it is taken off. The stopping point is determined on the scaffold, not in advance from the ground.
All the rubble - old brick, broken mortar, broken flaunching - needs to come down from height safely. On a scaffold setup, this is done using bags or a rubble chute. It should not be thrown from height onto the roof or dropped into the garden unsecured.
Once the stack is down to the last sound course, that course needs to be prepared properly before any new brickwork goes up. Loose mortar is raked out. The surface of the bricks is cleaned. A flat, level base is essential - new courses built on an uneven base will not run level, and a chimney stack that is not plumb from the base will lean again over time.
This preparation stage is easy to rush, especially on a day-rate job when the visible rebuilding has not started yet. It is worth asking what preparation is planned for the base course before new brickwork begins.
New courses go up in the same bond pattern as the existing stack - typically stretcher bond or English bond on older stacks. Matching the bond pattern keeps the rebuilt section from looking visually disconnected from the courses below.
Mortar mix is matched to the brickwork type. On older softer bricks a lime-containing mix is appropriate; on denser modern brickwork a standard cement mortar is used. Each course is checked for level and plumb as it goes up. Joints are finished to match the existing pointing profile - either a slightly recessed tooled joint or a weather-struck joint that directs water out and away from the face.
On a chimney stack with more than one pot, each flue position is maintained through the new courses - the internal flue liners or air paths need to correspond correctly with the pots above. This is straightforward on a like-for-like rebuild but worth confirming if the number of pots is being changed.
Once the brickwork reaches the correct height, the pot is seated on the top course in a fresh mortar bed. It should sit level and centred, with the flue opening inside it properly aligned with the flue below. The pot is then surrounded with fresh flaunching - a dome of mortar that slopes away from the pot on all sides so water runs clear.
Flaunching needs to be given time to cure before the scaffold comes down and before frost threatens it. In cold weather this may mean covering the top of the stack with a protective sheet for a day or two to allow the mortar to set without being frozen before it has cured.
The lead flashing goes back in once the brickwork has cured sufficiently to hold it. Step flashing is cut into the mortar joints on the sides of the stack, with each piece overlapping the one below. The back gutter - the lead that sits behind the stack on the uphill side - is re-dressed to ensure water running down the roof is directed around the base of the stack rather than behind it.
Every joint where the lead enters the brickwork is pointed up with mortar. Mastic alone is not a substitute for proper pointing - it does not bond to brick in the same way and it degrades faster. If a previous repair has used mastic at the flashing joints, this should be cleaned out and pointed properly during the rebuild.
Once the chimney itself is complete, attention turns to the roof below. Tiles or slates disturbed during the scaffold erection or during the work are refixed. Any debris that has fallen onto the roof slope is removed. Gutters should be cleared of mortar dust and brick fragments - fine mortar residue in a gutter will set solid over time and reduce the gutter's capacity.
The scaffold comes down once the mortar has cured and the flashing is in place. The scaffold company will usually need a day's notice to strike the scaffold, so this is planned in advance. After the scaffold is down, a final visual check from the ground confirms everything looks correct - pot centred, flaunching sloping cleanly, no mortar smeared on the tile faces.
We carry out chimney rebuilds in Haverhill and the surrounding area, including Newmarket, Bury St Edmunds, Cambridge and the nearby villages. If your chimney stack needs attention, call us to arrange a proper inspection so we can tell you exactly what the job involves before any work starts.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
