Steve: If your spray foam installer leaves the vents open, he will be committing the 2nd of the 4 problems I described above. You will most likely have comfort and efficiency problems. You may well have condensation problems. You will be spending a lot of money on a product that likely won't perform as it should. Don't let him leave the vents open. If the installer you've chosen doesn't understand this, you may want to choose someone else. https://youtube.com/v/ggLAUsiuI_o?version=3
Spray foam insulation systems effectively seal walls, roofs, corners and other surfaces, creating a more comfortable household because it provides a barrier against drafts and associated pollen and dust. Long-term, properly installed spray foam won’t change its form or shape, meaning it will deliver the same benefits that it did years—or even decades—after being installed, while other insulation materials may settle and create future gaps in the insulation.
Today’s “third generation” of blowing agents have a GWP of 700 to 1000 which is still remarkably high considering water/CO2 has a GWP of 1. However, innovation from some chemical manufacturers like the Chemours Company have introduced the next generation of HFO blowing agents such as Opteon 1100, which significantly reduces the GWP impact when using closed-cell spray foam insulation products.
How Much To Charge For Spray Foam Insulation
Carefully examine the roof membrane (surface material) for cracks, tears, blisters, evidence of ponding, exposed foam, and open seams. If already coated, evaluate the condition of the coating. Pay particular attention to areas around roof penetrations (vents, skylights, pipes, etc), ponding areas, cracks in parapet walls, and the attachment of roof membranes to parapet walls. Roofs should be in good condition to warrant coating.