Pitched Roofing Underlays

Pitched Roofing Underlay Product Selector

Find the right pitched roofing underlay for your project.

Underlay Selection - Areas of Application & Ventilation Requirements

A number of design considerations need to be taken into account when constructing new pitched roofs or in refurbishment of existing roofs. The area of application will determine the minimum product choice from the Icopal range in terms of ventilation required or mechanical performance.


Selecting The Correct Underlay To Resist Wind Uplift

One of the functions of an underlay or breather membrane is to reduce the wind load, generated under wind gusts, that acts on the underside of the roof slates or tiles.

This issue is addressed in the BS5534 Code of Practice for Slating and Tiling. The selection of the correct underlay or breather membrane is dependent on the exposure of the roof to wind uplift, the type of roof construction specified and roof tile batten gauge. It may also be necessary to seal the lap of underlay. 

A consequence of the incorrect selection of appropriate underlays or breather membranes is an increased risk of the roof covering becoming dislodged.

Click here to find the correct underlay or breather membrane for your roofing project and to ascertain whether it complies with the wind uplift zonal performance requirements of BS5534.

For further more detailed information regarding the selection and installation of pitched roof underlay, please consult our Design Guide.

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