It would be better to use a closed cell 2 pound density foam because it doesn t expand as much as open cell and is more likely to fill voids but not go through them.
Open cell spray foam metal roof.
We already know open cell spray foam is risky in cold climates.
However i own a spray foam rig and i wouldn t bother putting more than about 8 of open cell or 5 closed cell.
Some spray foam manufactures have tested primer coating products that result in the formulation of a class ii vapor retarder directly on the surface of the open cell spray foam.
Open cell spray foam can also be used to create an unvented attic in cold climate zones provided code requirements for a vapor retarder are followed.
The big picture concern is actually more about trapped moisture than whether the substances that make up spray foam insulation will corrode steel or metal sheets.
There seem to be no chemicals in spray foam that could react with steel or the galvanized protective coverings on the metal siding and roofing panels.
Less common of the two types of spray foam open cell is mostly used for residential and commercial insulation.
Spf insulation consists of isocyanate and polyol resin that is chemically combined and applied to surfaces using a spray gun.
Open cell spray foam is made of open cells that are softer and flexible with the physical structure similar to a sponge shape.
One would be if someone went on the cheap and used open cell spray foam rather than closed cell.
Open cell spray foam.
How ducts in an unvented attic should be installed.
Closed cell foam provides better insulation than open cell and also functions as an air barrier.
Strong material that can strengthen walls roofs structure.
Spf insulation can be open cell or closed cell.
As a result in iecc climate zones 5 and higher building codes require the use of a vapor retarder if you install open cell spray foam.
Open cell foam provides insulation and air sealing for a building but is water and vapor permeable.
Moisture from indoors can diffuse through the foam and find the cold roof sheathing where it accumulates and eventually rots the roof.
In our neck of the woods closed cell foam costs about 56 more than open cell.
An open cell foam about 0 5 pound density is the most cost effective way to insulate but any opening over 1 16 could cause the foam to expand out onto the roof.
Most steel roofing is factory finish painted which adds yet another barrier surface in the interior primer paint coat which further isolates the steel from the spray foam.