Sarking in roof constructions
The term ‘sarking’ can have a number of different meanings relating to roof construction.
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.
A typical roof build-up that contains sarking is as follows (from the bottom):
- 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.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
A transformative shift in the design, construction and management of built assets.
Apprenticeship announcement by the Prime Minister
Welcomed but with call for more actionable detail.
Heat pump announcements, what homeowners need to know
An 'ultimate guide to heat pumps' from a heating company.
Construction contract awards reach 7.1bn in February
Their highest level in seven months.
The journey to sustainability in heritage
Research is the key to better understanding.
Heritage approaches to adaptation, mitigation and loss.
Bridging the gap between policy, finance and installation.
Development on brownfield land
Definition, background, policy and the latest consultation.
With the Design Framework for Building Services.
Retrofit of Buildings, a CIOB Technical Publication
Pertinent technical issues, measures and the roles involved.
ECA joins HSE campaign to support mental health
Working Minds’ five simple steps based on risk assessment.
Mental health in the construction industry
Mental health issues in brief with related articles.
Transitional arrangements, Building Control and the BSR.
For pre-October buildings with substantial progress by April.
Why quality counts in domestic ventilation systems
From products, to systems to the installation.
Empowering the Future with CIOB Academy
Lifelong learning, upscaling, and reskilling for the built environment.