When a chimney needs more than a patch, Ely Roofers carries out full chimney rebuilds in Bar Hill and nearby areas, using the right materials for a lasting result.
A chimney rebuild means taking the stack down to just above the roofline and building it back up with new brickwork, a new damp-proof course (DPC), and properly bedded lead flashings at the roof junction. It is not a cosmetic job - it is structural work that has to be done correctly if it is going to last. The materials chosen at each stage determine how long the finished stack performs before it needs attention again.
The brick used in a rebuild matters more than most homeowners realise. The priority is matching the existing stack as closely as possible in colour, texture and format. A stack rebuilt in a noticeably different brick looks out of place and can affect the appearance of the whole roofline.
Beyond appearance, brick type affects durability. Chimneys above the roofline are fully exposed to rain, frost and wind, so the brick needs to be a good-quality, frost-resistant engineering or facing brick rated for external use. Soft or porous bricks absorb water and spall quickly under freeze-thaw conditions.
Reclaimed bricks are sometimes used to achieve a closer match on older properties. They can work well cosmetically, but it is worth checking that any reclaimed stock is in sound condition with no previous spalling. A brick that has already spalled once is likely to spall again.
The mortar mix used to rebuild the stack needs to suit the brickwork. Using a hard, cement-rich mix on softer bricks is a common mistake in repair work. When the mortar is harder than the brick, any movement causes the brick face to crack rather than the joint. Moisture gets trapped rather than being able to escape, which speeds up deterioration.
For most residential chimneys, a moderately hydraulic lime mortar or a correctly proportioned sand-cement mix at around 1:4 or 1:5 is appropriate. The roofer should be able to explain what mix they are using and why. If the answer is simply "cement and sand," ask what ratio and whether it suits your brick type.
A DPC tray at the base of the rebuilt stack - above the flashing level - is essential to stop water tracking downward through the stack into the roof structure. Without one, even a well-built stack will let moisture through over time.
The standard material for a chimney DPC tray is Code 4 lead sheet, dressed carefully to line the inside of the stack at the correct height and to shed any water outward over the flashings. Some contractors use proprietary plastic DPC trays, which are cheaper and quicker to fit but can be less durable and harder to dress precisely to the shape of the flue opening. Lead is the trade standard for a reason: it is malleable, long-lasting and proven in this application.
The junction between the chimney stack and the roof slope is sealed with lead flashings. These are arguably the most critical detail in a chimney rebuild. A flashing that has been cut short, poorly dressed into the mortar chase, or fixed with the wrong sealant will fail within a few years.
A proper flashing installation on a rebuilt chimney includes:
The standard material for chimney flashings is milled lead sheet. Cheaper alternatives such as aluminium flashing tape or self-adhesive products are sometimes used on lower-cost repairs. They are not appropriate for a rebuild - they have a much shorter service life and are not a like-for-like replacement for properly dressed lead.
At the time of a rebuild, it is worth deciding what to do with the chimney pot. If the flue is still in use, the pot should be replaced or reused if it is sound, and a cowl fitted to reduce rain entry. If the flue is no longer used, capping the pot properly with a ventilated terminal keeps moisture out while allowing the flue to breathe and prevents condensation problems at the fireplace below.
Leaving a disused flue open is not recommended. An open pot lets rain fall straight down onto whatever is at the base of the flue, and can allow birds to nest in the stack.
When getting quotes for a chimney rebuild in Bar Hill or nearby, ask each contractor specifically: what brick are you proposing, and can you source a close match? What mortar mix will you use? Does the quote include a new lead DPC tray and full lead flashings? Getting clear answers to these questions tells you immediately whether the quote is for a proper rebuild or a cheaper version.
Call Ely Roofers to book a roof-level inspection and get a straightforward quote for your chimney rebuild.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
