Windows: interior sealing
– Andersen* (window manufacturer) says: fill interior 1/3 of cavity w low expanding foam and then sealant on top; do not overfill or will result in poor performance
– DuPont says: do not use foam at sill or 6” up jambs from sill (probably where vapor closed flexwrap NF was using as flashing); then sealant on top.
– Insulator says: Great Stuff spray foam all around window
– 475 says: do not use spray foam anywhere and especially not at windows, use only mineral wool
1) Good practice to use Great Stuff spray foam then something like OSI Quad Max caulk overtop?
2) But window manufacture and DuPont say for some reason Not to use too much foam and/or Not to use Any foam at sill at up jambs 6” – why is this? What should we do?
* windows are Andersen Fibrex windows