TR-22 – Ridge Detail: Pitched Cold Roof

This pitched cold roof ridge detail shows a typical junction incorporating a proprietary mechanically fixed dry-ridge system.

The drawing illustrates half-round ridge tiles, vented filler units, a treated ridge batten and bracket, roof battens, breathable roofing underlay and roof trusses or rafters. It explains how the roof covering and underlay should be completed at the ridge while maintaining any required high-level ventilation.

For the corresponding facing-brick construction, see our TB/22 cold-roof ridge detail. Approved Document C provides the official guidance on resistance to moisture and roof ventilation.

Supporting notes cover:

• Proprietary mechanically fixed dry-ridge systems.
• Mechanical fixing of individual ridge tiles.
• Roofing-underlay laps and termination.
• Ridge battens, brackets and straps.
• High-level ridge ventilation where required.
• Coordination with low-level eaves ventilation.
• Weatherproof and insect-resistant ventilation openings.
• Ceiling-level insulation continuity.
• Vapour-control and airtightness layers.
• Structural design of rafters, trusses and apex connections.
• Fire-stopping where a separating or compartment wall meets the ridge.
• Condensation control in accordance with the roof design.

The customer receives one downloadable PDF construction drawing, drawn at 1:10 and formatted to fit an A3 sheet.

The dry-ridge system, ventilation and underlay arrangement must be coordinated with the roof covering, condensation-risk assessment and manufacturers’ installation requirements. Trusses, rafters and roof bracing remain subject to structural design.