This code covers the recommended procedures for waterproofing roofs using bitumen felts. It provides guidelines on surface preparation, application of bitumen primer, proper laying techniques (overlaps and staggering), and outlines the specifications for four-course, six-course, and seven-course waterproofing treatments.
Code of Practice for Waterproofing of Roofs with Bitumen Felts
Quick Reference Values
Minimum side overlap for bitumen felts75 mm
Minimum end overlap for bitumen felts100 mm
Recommended slope for flat roofs1 in 60 (minimum 1 in 100)
Nominal application rate of bitumen bonding material per coat1.2 kg/m²
Practical Notes
Ensure the roof surface is completely dry, clean, and appropriately sloped before applying the bitumen primer to ensure maximum adhesion.
Always start laying the felt from the lowest point of the roof slope (near the drain) and proceed upwards towards the ridge to prevent water ingress at the overlapping joints.
End laps in adjacent rolls must be staggered to avoid the formation of continuous weak joints.