I have a spray foamed attic.
Spray foam ceiling or roof.
Nope you absolutely do not need to ventilate a spray foam house and here s why.
Because basically now that attic is a conditioned space.
It s terrific because it s pretty much the same temperature as the rest of the house all the time.
Open or closed cell spray foam is applied to the underside of the roof sheathing and additional fiberglass or cellulose insulation is blown in as a cost saving method for meeting high insulation requirements and filling in the cavity space between the rafters to the ceiling deck.
The closed cell spray foam stops air infiltration and provides about an r 5 per inch.
You can install spray foam on the underside of the roof sheathing to create an unvented conditioned attic.
Eco spray foam insulation.
The spray foam creates an airtight bathtub that is then filled with air permeable insulation such as fiberglass or cellulose.
Made with plant based products such as soy eco spray foam is more eco friendly.
It is critical to provide air sealing at the perimeter to control wind washing of air permeable insulation.
Products with a higher r value provide greater insulation.
Even though your attic is large this makes sense because you don t want to install your ducts or hvac equipment outdoors.
Installing insulation attics one of the high tech insulation products being utilized these days is a foam spray product called icynene which is a foam that starts as two liquid components a and b if you will that are heated up and sent through two hoses and meet at a tip of a gun where the magic begins.