Why / when should I use a bitumen roofshingle underlay?
A bitumen roofshingle underlay is a bitumen membrane. The use of an underlay is recommened for a number of reasons. In general an underlay protects decking material from wind-driven rain. So, it works like a safety net. The use of a bitumen roofshingle underlay also reduces “picture framing”. Picture framing is the visible outline of deck panels caused by irregularities in roof decking thickness. For slopes lower than 20° we strongly recommend the use of a bitumen roofshingle underlay. IKO offers several types of bitumen roofshingle underlay under the brand name Armourbase.
