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
BSRIA European air conditioning market update 2024
Highs, lows and discrepancy rates in the annual demand.
50 years celebrating the ECA Apprenticeship Awards
As SMEs say the 10 years of the Apprenticeship Levy has failed them.
Nominations sought for CIOB awards
Celebrating construction excellence in Ireland and Northern Ireland.
EPC consultation in context: NCM, SAP, SBEM and HEM
One week to respond to the consultation on reforms to the Energy Performance of Buildings framework.
CIAT Celebrates 60 years of Architectural Technology
Find out more #CIAT60 social media takeover.
The BPF urges Chancellor for additional BSR resources
To remove barriers and bottlenecks which delay projects.
Flexibility over requirements to boost apprentice numbers
English, maths and minimumun duration requirements reduced for a 10,000 gain.
A long term view on European heating markets
BSRIA HVAC 2032 Study.
Humidity resilience strategies for home design
Frequency of extreme humidity events is increasing.
National Apprenticeship Week 2025
Skills for life : 10-16 February
Update on the future of Grenfell Tower
Deputy Prime Minister decides for it be carefully taken down to the ground.
Ending decades of frustration, misinformation and distrust.
Essential tools in managing historically significant landscapes.
Classroom electrician courses a 'waste of money'
Say experts from the Electrical Contractors’ Association.
Wellbeing in Buildings TG 10/2025
BSRIA topic guide updates.