02 — EARLY DESIGN INPUT

Resolving the roof before the structure was finished

When Neal Roofing first became involved, the building comprised a steel frame, timber roof structure and partially completed external envelope.

This allowed the roofing strategy to be considered before critical dimensions and interfaces became fixed.

Working alongside the site joiner, the roof build-up, perimeter gutter geometry and ventilation requirements were developed together so that the finished metal roof could operate as an integrated system.

03 — THE CHALLENGE

A gutter intended not to be seen

The architectural brief required rainwater collection to remain largely concealed behind the external elevations.

This created a significant design responsibility. Outlet positions, gutter depth, falls, membrane interfaces and finished cladding levels all needed to be coordinated before work progressed.

Because concealed gutters provide fewer visual indications of developing problems, secondary overflow and fail-safe details were also incorporated so that blockage would not result in water entering the building envelope.

07 — COLD-ROOF VENTILATION

Airflow was part of the roof design from the outset

Because the roof was constructed as a ventilated cold roof, an uninterrupted ventilation path beneath the zinc substrate was fundamental to the design.

Ventilation openings were incorporated at low and high level to encourage continuous airflow through the roof construction.

Stainless-steel insect mesh was used at exposed ventilation points to retain airflow while restricting insect and animal access.

A counter-battened zone beneath the plywood deck provided the ventilation cavity required between the roof structure and the fully supported metal covering above.

The detail demonstrates why zinc roofing cannot sensibly be considered independently of the construction beneath it.

09 — ROOFLIGHT INTEGRATION

Designing an interface that did not already exist

Several large Neo rooflights from The Rooflight Company were incorporated into the zinc elevations.

The proposed units did not arrive with a ready-made detail suitable for the particular roof build-up and surrounding standing-seam zinc.

The interface therefore had to be developed as part of the roofing package, considering upstand dimensions, zinc weathering, drainage and the position of the underlying ventilation zone.

Resolving these details before the roof covering was installed reduced dependence on improvised site alterations at a later stage.

The Rooflight Company →

11 — TECHNICAL KNOWLEDGE

Metal roofing depends on the construction beneath it

Successful hard-metal roofing requires consideration of substrate, thermal movement, moisture, ventilation, fixing, drainage and interface detailing alongside the finished metal itself.

Zinc Roofing →
Metal Roofing Guidance →
Roofing Regulations + Standards →
BS 8000 Workmanship →

12 — DESIGN + CONSULTANCY

Early technical input can simplify complex roofing

This project illustrates the benefit of involving the roofing contractor before the adjoining construction has been finalised.

Roof build-ups, gutter depths, insulation zones, rooflight positions and finished levels can then be coordinated before they become expensive to alter.

Where clients require professional roof investigation, specification or independent building-envelope advice, Strut Building Surveyors provides a separate consultancy service.

Strut Building Surveyors →