Difftak Bison 175

Bison DiffTak 175 is a vapour permeable underlay that provides a reliable solution for protecting roof structures. Installed either over the raw shingles or directly onto the rafters, this effective protective layer is designed to manage water vapour from the inside while resisting the elements from the outside. Its ability to promote vapour transport contributes to a healthy and moisture-free building. Please note that the product is not suitable for use with impregnated wood and that the pitch of the roof should be at least 14° for optimal performance.

DiffTak 175 Bison is designed to give your roof optimal protection. This diffusion-open underlayment is installed directly underneath the top layer to effectively wick moisture away from the roof structure while keeping water and wind outside. Its installation is quick and easy, either directly onto the rafters or on top of the trusses without the need for an air gap. It is important to note that DiffTak 175 Bison is not penetration resistant and therefore care is required during installation. The minimum roof pitch requirement where the underlay can be applied is 14°. Please also note that the product should not be installed in contact with impregnated wood to ensure material compatibility.