How-to · 4 min read · Updated 6 November 2026
Chimney breast removal and knock-throughs: planning the rubble
Why these jobs produce so much waste
A chimney breast is solid masonry, often two storeys of it, with flues, hearths and sometimes a concrete hearth slab. A knock-through removes a section of wall that may be a single brick thick in a newer house or a full nine inches in a Victorian one. Either way the waste is dense, heavy and comes out in a short burst over a day or two.
Structural work like this needs proper support, usually a steel beam or gallows brackets, and Building Regulations approval. That is a job for your builder and engineer. This guide is about the part that often gets forgotten in the planning: where the rubble goes and how it leaves the property.
Typical waste from common jobs
| Job | Typical rubble produced |
|---|---|
| Ground floor chimney breast only | About 1 to 1.5 tonnes |
| Chimney breast on two floors | About 2 to 3 tonnes |
| Knock-through between two reception rooms | About 0.5 to 1.5 tonnes |
| Kitchen extension wall opening | About 1 to 2 tonnes |
| Removing a stack above the roofline | Extra 0.5 to 1 tonne, plus tiles and lead |
These are rough guides. Wall thickness, plaster depth and whether a concrete hearth is broken out all change the total.
Step by step: keeping the clear-up under control
- Agree with your builder who is responsible for the waste before work begins
- Clear and sheet the room, seal doorways with dust sheets and tape, and cover floors along the route out
- Keep a supply of rubble bags and fill them as work progresses so the floor does not overload
- Fill bags only to a weight one person can carry, around 20 to 25 kg
- Stack bags by the exit, not against walls that are being worked on
- Keep timber, plasterboard, metal and lead in separate piles
- Book a collection for the day the heavy work finishes, not a week later
Dust and safety
Brick, mortar and concrete release respirable crystalline silica when broken, cut or swept dry. The Health and Safety Executive treats silica dust as a serious lung hazard, so builders should be using dust suppression or extraction and suitable masks such as FFP3. If you are clearing up yourself, damp the debris down lightly before shovelling, wear a proper mask rather than a paper one and avoid dry sweeping.
Old chimneys can also contain soot, which is messy and should be bagged separately where possible. If the house has textured ceilings, old boards or flue pipes that might contain asbestos, have them checked before anything is broken out.
Getting the waste out of the house
Most chimney breast and knock-through waste has to come through the house, which is why the route matters as much as the volume. A front room job may only need bags carried a few metres to the drive. A first floor chimney breast in a terrace may mean two tonnes carried down the stairs and through the hall.
If there is no space for a skip, or a skip would need a road permit, a wait-and-load or hand-ball collection is often simpler. The crew carries the bags from where they sit, loads them straight onto the vehicle and leaves nothing on the road.
Cost and timing
Rubble from these jobs is mostly clean brick, mortar and plaster, which keeps disposal costs reasonable as long as it is kept apart from timber and rubbish. As a guide, a one to two tonne collection of bagged brick and concrete typically costs £150 to £300 where the bags are close to the vehicle, and hand-ball jobs through the house usually £150 to £400 depending on the carry.
Timing matters more than most people expect. Rubble left in the house overnight spreads dust into every room and gets in the way of the next stage, whether that is fitting the steel, plastering or laying the floor. Booking the collection for the afternoon the breaking-out finishes keeps the job moving and stops bags lining the hallway for days.
- Tell the collector how many bags there are and how far they must be carried
- Mention stairs, narrow halls and parking restrictions outside
- Say whether there is soot, timber or old lead to go as well
- Ask for a fixed price based on photos rather than an estimate on the day
Should you use a skip?
A mini or midi skip can work for these jobs if you have a drive, but heavy rubble fills a skip's weight limit quickly and a skip on the road needs a council permit. Skips also tend to attract other people's waste and sit for days. For a one-off burst of one to two tonnes, a single collection on the day is often less hassle.
Frequently asked questions
Can I put chimney rubble in a normal skip?
Usually yes, as long as it is mostly brick, mortar and plaster. Soot can normally go with it in small amounts, but check with the skip firm. Keep plasterboard, timber and any material that might contain asbestos out of the skip. Watch the weight limit, because a mini skip full of brick can easily exceed what the lorry is allowed to lift.
How many rubble bags will a chimney breast fill?
As a rough guide, a single-storey chimney breast fills around 40 to 60 standard rubble bags of 20 to 25 kg each, and a two-storey breast can fill 80 to 120. The number depends on wall thickness and how much plaster comes off with it. Having more bags than you think you need avoids loose rubble piling up on the floor.
Who should remove the rubble, me or the builder?
Whoever produces the waste. If your builder is doing the work, the waste is theirs and their quote should say whether removal is included. If you are doing the knock-through yourself, the waste is yours and you need to use a registered waste carrier. Either way, agree it in writing so the pile is not left behind.
chimney breast knock-through renovation waste dust control
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