Chimneys on new build housing schemes are often an afterthought in the scaffold programme. The scaffold is planned around the main elevations. The chimney appears as a small additional piece of work that needs its own separate scaffold or an extension of the main scaffold. Neither approach is difficult in principle. Both are consistently underestimated in duration and cost.
The specific issue is that chimneys require scaffold access at the roof level, above the eaves, at a point where the main scaffold has usually been designed to stop. Extending the scaffold up to and around the chimney requires additional lifts, additional tie provision, and often additional design work because the geometry at chimney level is different from the geometry at eaves level.
On residential schemes with multiple plots featuring chimneys, the total cost of chimney scaffold across the scheme can be meaningful. Each chimney requires its own arrangement. Each takes time to erect, use, and strike. Across a hundred-plot scheme with fifty chimneys, the cumulative programme time is substantial.
The programme delay is where the cost most often lands on the developer. Roofers cannot finish a plot with a chimney until the chimney has been dressed, flashed and completed. If the chimney scaffold is not ready when the roofers arrive, the plot cannot close. Where multiple plots hit this constraint simultaneously, plot completion dates slide.
Globe Cambridge's scaffold designs on chimney-heavy schemes include the chimney arrangement from the outset rather than as a retrofit. Each plot's scaffold is designed to include the chimney access requirements from the initial erection. Where the chimney is being added later in the programme, the base scaffold is configured to accept the addition without major modification.
There is a specific safety consideration around chimney scaffold that is worth flagging. Working at the top of a chimney is a high-risk activity even by construction standards. The workspace is small, the height is significant, and the trades using it are often not scaffolders themselves. Bricklayers finishing a chimney head, or roofers dressing the flashings, are working in an area that has to be properly protected regardless of who is using it.
Edge protection at chimney level therefore needs to be more comprehensive than a generic scaffold might provide. Complete guardrails around the chimney. Toe boards to prevent tool drops onto the roof below. Fall protection considerations for the work itself. Each is a small detail. Together they represent additional scope on the chimney scaffold that generic pricing does not always capture.
For developers reviewing scaffold tenders on schemes with chimneys, the question worth asking is what the chimney scaffold approach is and how it is priced. A contractor who has thought about it produces a specific tender. A contractor who has not treats chimneys as an extension of the main scaffold and prices generically. The two approaches produce different site outcomes and different final costs.
On heritage or refurbishment work where the chimney is an existing structure, the assessment is more demanding again. The chimney's structural condition affects whether scaffold can be tied to it, what loads it can bear, and what supplementary support may be required. Globe Cambridge's approach on heritage work includes structural review of chimneys before scaffold design is committed. Where the chimney cannot safely support scaffold, alternative arrangements are proposed rather than assumed away.
For QSs pricing chimney scaffold provisions across housing schemes, the practical advice is to treat the chimney as a specific package rather than as an incremental extension of the main scaffold. The cost is meaningful. The programme risk is meaningful. Both deserve explicit treatment at cost plan stage rather than absorption in the scaffold sum.
Talk to Globe Cambridge To discuss scaffold around chimneys on residential schemes on your scheme, contact Globe Cambridge on 01223 890727 or email enquiries@theglobegroup.co.uk.
