Closed cell spray foam can be used in any climate.
Rigid foam on roof unconditioned.
That includes the sloped roof assembly above the small triangular attics behind your kneewalls.
Rigid insulation is one of the best tools to reduce your energy costs.
You can use 2 inch thick rigid foam as a ventilation baffle if you want.
Install it anywhere from the roof to the foundation.
Humid or cold climates require either rigid foam insulation above the roof deck to keep its temperature above 45 f throughout the year or spray foam insulation under the roof deck to keep interior moist air from contacting it.
In so bearing shouldn t be an issue.
Gable end detail overhang cut and then rebuilt to hide the thickness of the over roofing rigid insulation.
Silverglo has an integral radiant barrier to reflect summer heat out and winter heat back in.
You can even place it under the foundation slab.
Rigid foam insulation also known as insulating boards provide high r values.
Foam roofing bonds around roof penetrations such as pipes vents and edges forming an impenetrable wedge leaving these penetrations high and dry additionally the roof surface is built up in ponding areas to eliminate heavy standing water and improve drainage.
A vented attic is basically outdoors so installing rigid foam above your roof sheathing is a waste of money and a waste of rigid foam.
All of the sloped roof assembly from the soffits to the area above the small flat ceiling above your second floor needs to be insulated to r 49.
Install rigid insulation board in multiple layers with joints offset vertically and horizontally between adjacent layers.
Now comes the really really big point.
Superior air sealing performance eliminates energy wasting leaks at the top of the house.
The 6 inches of rigid insulation added to the top of the existing roof deck needed to be done in a manner that was invisible.
If you have a vented attic it makes no sense to install rigid foam above the roof sheathing.
For larger roofs you may need to provide direct framing to framing contact.
Either 1 install an adequately thick layer of rigid foam on the exterior side of the roof sheathing or 2 install an adequately thick layer of closed cell spray.
On small porches as long as you use a 2x plate where the rafters meet the foam it should be fine.
Rigid insulation layers exterior to existing roof sheathing must provide sufficient thermal insulation r value to control condensation risk see climate specific guidance.
You might as well put the rigid foam in the branches of a tree in your back yard.
Silverglo rigid foam insulation is durable and waterproof it won t shrink or lose r value over time.
Foam typically used on roofs can support 15 lb.
If you want to create an unvented roof assembly that is an assembly that lacks the ventilation gap between the insulation and the roof sheathing you have only two choices.
The foam layer is waterproof rigid and custom contoured to improve drainage.
