If you're having a chimney stack taken down at your Thetford property, here's a clear account of what each stage of the work involves, from the initial assessment to the moment the site is left tidy.
Before any brickwork is touched, the chimney needs to be properly assessed. A look from the ground tells you whether the stack is leaning, whether pots are displaced, and whether there's obvious spalling or crumbling mortar. But to know the full picture, a closer look is needed - which usually means access via scaffolding or a ladder, depending on the height and pitch of the roof.
At this stage, the key things to check are: the condition of the existing brickwork, whether the stack has any structural movement, the state of the lead flashing at the base of the stack, and what's underneath the tiles immediately around the stack. If the flashing has been leaking, the rafters or sarking felt below may be damaged and will need attention as part of the job.
The assessment also establishes which tiles currently abut the stack. Knowing the tile type and profile early is important for sourcing a good match before work begins - not as an afterthought after the stack is already down.
Chimney take-down work is carried out at height, and setting up correctly protects both the people doing the job and the property below. For most two-storey houses, scaffolding provides the safest working platform. A scaffold allows the brickwork to be dismantled in a controlled way, with material lowered down rather than dropped. It also protects gutters, conservatories, and anything else below from falling debris.
Where the stack is low on a single-storey outbuilding or extension, a properly footed ladder and standoff may be sufficient. The decision depends on the height, the complexity of the work, and what's below. Scaffolding costs are part of the overall price and should be included clearly in any quote you receive.
Work begins at the top of the stack. The chimney pots are lifted off - or carefully broken off if they've been heavily mortared or have cracked through. The flaunching, which is the sloped mortar collar that beds the pots in place, is then broken out and removed. Flaunching on older stacks is often in poor condition - cracked, hollow, or entirely detached from the brickwork beneath.
If the pots are in good condition and are decorative or unusual - for example, tall Victorian terracotta pots - it's worth having a conversation before the job starts about whether they're worth saving for resale. Once they're broken up and in the skip, that option is gone.
This is the main physical work. The brickwork is taken down course by course, working from the top downwards. Bricks are either stacked for lowering in a hod or rubble bag, or broken up and removed in sections depending on their condition and the ease of dismantling.
Older chimneys built with lime mortar often dismantle relatively cleanly - the mortar is soft enough that a bolster and hammer will separate the joints without breaking the bricks. Stacks that have been repointed with hard cement mortar at some point are more difficult to take apart and may require a disc cutter or demolition tool for parts of the work. This can add time to the job.
The stack is taken down to just below the roof line - typically one or two courses below the tile surface. The remaining stub is cut back cleanly and the top surface is levelled off ready to receive the lead slate. Nothing is left protruding above the tile level.
Once the brickwork is down to the correct level, the existing lead flashing is stripped back. The flashing sat in cut chases in the brickwork and was dressed over the tiles. All of it comes away - including any mortar that was used to tuck it in, and any old sealer that was applied over the top. A clean surface is needed for the new lead work to sit and bond correctly.
At this point, the tiles immediately around where the stack stood are lifted carefully. This allows the roofer to check the condition of the battens and any sarking felt beneath. If the flashing had been failing, water may have been running under the tiles for some time. Damaged battens need to be replaced at this stage rather than tiled over.
The lead slate is the central weatherproofing component of a chimney take-down. It's a purpose-fitted piece of lead that covers the hole left by the flue and integrates into the surrounding roof covering. It should be dressed flat, turned up at any abutments, and lapped correctly by the tiles above it.
Lead is used for this because it can be worked into the exact shape needed, forms a permanent bond with itself and adjacent surfaces, and outlasts almost every other roofing material in regular use. The weight code of lead used matters - lead that is too light will be prone to thermal movement cracking over time. Code 4 or Code 5 lead is appropriate for most domestic applications at this location on the roof.
The lead should be fixed at the top and allowed to hang free below to accommodate thermal movement. If it is over-fixed or tacked down at both ends, it will crack at the fixing points over time as it expands and contracts with temperature changes.
Once the lead slate is in place, the tiles that were lifted are refitted, and the gap where the chimney emerged is tiled in to create a continuous, unbroken roof surface. The tiles used should match the existing ones as closely as possible.
On roofs with older clay plain tiles, sourcing a good match means looking at reclaimed material. Salvage yards often carry plain clay tiles in sizes and shades that match common regional types. New clay tiles are also available but won't match immediately - they'll weather in over a number of years. Concrete tiles are matched by manufacturer profile where possible.
Good tiling in this area means correct head-lap, properly aligned courses, and tiles that sit flat without rocking. Any tile that doesn't lie flat is a potential water trap.
With the roof watertight, the flue itself needs to be closed at the base. Without this, cold air will travel down the redundant flue and into the room below, causing draughts and heat loss. A common approach is to fit a ventilated cap at the throat of the fireplace - this keeps some air movement through the flue to prevent condensation from building up inside the sealed column.
This part of the work is often done by the homeowner or a builder separately from the roofing work, but it's worth confirming before the job starts who is responsible for it. A completed chimney take-down that leaves the flue open at the base is only half-finished.
All brickwork, mortar, old flashing, broken pots, and flaunching are removed from site. Nothing is left behind. This usually means a skip or a loaded van, depending on the volume of material. If a skip is being used, confirm in advance where it will be positioned and for how long.
The surrounding roof should be left in the same condition it was found - no cracked tiles, no displaced ridge tiles from working around them, no mortar left on finished surfaces. A quick final inspection from the ground before the roofer leaves is reasonable to ask for.
If you have a redundant chimney stack and want to know what's involved in having it removed properly, call Brandon Roofers. We'll come out to Thetford, assess the stack from close range, and walk you through exactly what the job will involve before you commit to anything.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
