- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 16 Jun 2018
Sarking in roof constructions
Sarking boards are typically softwood boards that are attached to the rafters of a pitched roof, below the roof-covering. They are typically around 150 mm wide and are used to provide additional support and strength to the overall structure.
They are used on buildings that can be exposed to high winds, heavy rain or other extreme weather conditions. As a result, they are more common in Scotland than in England or Wales. Boards tend to only be specified for new-build, not refurbishments, as this would entail a complete re-roofing with coverings being removed and replaced, and potentially exceeding the load-carrying capacity of the roof structure.
- Insulation (sitting either between-and-under or between-and-over the rafters).
- Sarking boards (with a gap of 2-3 mm between each one).
- Breathable membrane.
- Roof tiles or other covering.
The term 'sarking' can also refer to a pliable membrane such as a layer of felt, polystyrene or reflective foil, that insulates or reflects heat and can provide extra weather resistance. It can act as a protective second skin for the roof by helping to prevent storm-driven rain penetrating into the roof cavity. By helping to reduce draughts, it can also limit dust entering the building through gaps around downlights and vents, and help improve thermal performance.
 Find out more
 Related articles on Designing Buildings Wiki
Featured articles and news
A history lesson in geographic information systems.
A low tech, easy to use method of extinguishing small fires.
How can these valued spaces be reused?
Partnership avoids the need for listed building consent.
Connecting building design from inception to completion to operations.
Gregor Harvie predicts interoperability will be construction’s Uber moment.
Expert commentary and insight.
Guidance offered for stained glass window maintenance.
Define need before determining viability.
Framework examines social value of projects.
RfX or Request for [fill in the blank].
Organisation establishes Equality, Diversity, Inclusion taskforce.
Government announces plans for new building projects.
Outsourcing method to procure and manage supplies.