Accommodates up to a 20° pitch variation either side of the valley
Continuous support for the valley through must be provided using ply boards
Rafter pitch |
Max. valley length |
Min. lap length |
15 to 17° |
10.0m |
400mm |
17.5 to 22.5° |
12.0m |
350mm |
22.5 to 29° |
14.5m |
300mm |
30 to 34° |
15.0m |
250mm |
35 to 39° |
15.5m |
200mm |
40 to 44° |
16.5m |
150mm |
45 to 49° |
17.5m |
150mm |
50 to 55° |
18.5m |
150mm |
This table is a guide to the recommended application criteria. It assumes a standard roof intersection of 90° and a roof drainage area of 100m². For applications other than this, specific advice should be sought from our technical department.