I have read that mike oehler advices either 1 layer of 10 mil / 0.2 mm polyethylene or 2 layers of at least 4 mil / 0.1 mm polyethylene. And he advices to use EPDM for the roof.
However, I would like to know if it's preferred to use thicker foil in wet/cold climates?
I am planning on building a home in finland and am now considering to use 30 mil EPDM (0.6 mm) for the roof, 15 mil (0.3 mm) DPC for everything else. The only other foil that's available is PE building foil of 10 mil (0.2 mm).
If I can use PE building foil that would be great, however I would prefer to pay more now instead of getting mold issues later.
Pricing for these PE foils is as follows:
- EPDM 0.6 mm x 25 m x 1.2 m = 252,10 euro - DPC 0.3 mm x 50 m x 90 cm = 39,86 euro - Building foil PE 0.2 mm x 50 m x 2 m = 61,88 euro (4 m = 122,09, 6 m = 178,50 euro)