What membrane should i use under timber cedar shingles?
Shingle roofs over 22 degreesFor roofs over 22 degrees an air permeable type underlay can be used. This should meet the requirements of Annex A of BS 5534:2003+A1:2010.
Care should be taken with warm roof applications to follow current building regulations and individual specifications can be determined in conjunction with the insulation manufacturer.
Counter battens and battens should be used to create a vented space and again the underlay should meet the requirements of Annex A of BS 5534:2003+A1:2010.