VENTIA METAL Roof and Wall underlay with DRAINAGE MAT - A specialized, highly breathable, Branz Appraised roof and wall underlay (Ventia Iron 1137 & 1136) with an integrated drainage mat pre-applied.
Branz recommend this type of product is the most effective way to Retrofit wall Insulation in existing homes where the cladding is not being removed.
https://www.buildmagazine.org.nz/articles/show/insulating-external-timber-framed-walls
Also Designed for use under open-pan style metal roofing such as - Eurostyle, TRS Standing Seam, ESPAN, Eurotray, or Euroline where specific drainage and ventilation is required.It can help reduce the "oil canning" issue in long run sheets.
Installation Guide Retrofit Internal Walls - Ventia Metal Wall Underlay with Drainage Mat retrofit.pdf
Installation Guide External Wall & Roof - Ventia Metal Installation Guide Wall & Roof.pdf
