We are turning our roof into an unvented roof assembly by raising the roof and blowing in SPF. We are planning to leave the existing vapor barrier down but remove the fiberglass batting and then adding 6" of SPF in all the cavities, to completely seal and insulate the house. Should we have any concerns about doing it "upside down" and not spraying the foam directly to the underside/sheathing of the roof? Insulation Spray Coating

The deposition efficiency is typically low for alloy powders, and the window of process parameters and suitable powder sizes is narrow. To accelerate powders to higher velocity, finer powders (<20 micrometers) are used. It is possible to accelerate powder particles to much higher velocity using a processing gas having high speed of sound (helium instead of nitrogen). However, helium is costly and its flow rate, and thus consumption, is higher. To improve acceleration capability, nitrogen gas is heated up to about 900 °C. As a result, deposition efficiency and tensile strength of deposits increase.[1]
The problem was that the installer was doing his first spray foam job ever, and the thickness of the insulation varied from zero (visible roof deck) to about 9". Unfortunately, good average thickness doesn't cut it. The coverage needs to be uniform because a lot of heat will go through the under-insulated areas. (See my article on flat or lumpy insulation performance.) Insulation Spray Coating
Henry 587 Dura-Brite White Elastomeric Roof Coating is Henry 587 Dura-Brite White Elastomeric Roof Coating is a premium high solids formula offering better weather protection solar reflectivity and longevity than economy grade reflective roof coatings. Cured coating forms a permeable membrane which prevents liquid infiltration but allows moisture vapor to vent or breathe out of underlying substrate. Recommended ...  More + Product Details Close
“Since most of mechanical heat is IR heat, ceramic coatings can be used to prevent heat loss from inside a building,” Pritchett says. A home interior coated in ceramic paint can therefore reduce energy costs due to heat loss in the colder months. “We estimate that a home can save up to 40 to 50 percent in energy costs using our product,” Pritchett says. Payback on a product like SuperTherm, which retails for about $100 per gallon, can come in as little as two years.
The PPG logo is a registered trademark and Colorful Communities and We protect and beautify the world are trademarks of PPG Industries Ohio, Inc. © 2018 PPG Industries, Inc. All Rights Reserved. | Legal Notices & Privacy Policies | CA Transparency in Supply Chain Disclosure | Global Code of Ethics | TISC for PPG Architectural Coatings UK Limited | TISC for PPG Industries (UK) Limited | PPG Industries UK Ltd 2017 Gender Pay Gap Report Insulation Spray Coating
We are turning our roof into an unvented roof assembly by raising the roof and blowing in SPF. We are planning to leave the existing vapor barrier down but remove the fiberglass batting and then adding 6" of SPF in all the cavities, to completely seal and insulate the house. Should we have any concerns about doing it "upside down" and not spraying the foam directly to the underside/sheathing of the roof? Insulation Spray Coating
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.   Spray Coating Services

This is in great contrast to my friend's experience. Her attic spaces were sprayed and the foam is actually pretty, and I was in her attic 6-7 days after it was sprayed and could hardly smell anything when I stuck my face up to the foam. And she did not have to clean up one speck of dust during or after the spraying. I got the name/number of the guy from her who managed her attic project, but between the time he did my house and the time he did her house, he was let go from the company who did her attic and hired by another company. He assured me everything would be the same, etc., etc., and I had no reason to believe anything had changed, but the sprayers who did my house later admitted they had never sprayed an attic before and I also found out that the foam used in my attic was from a different manufacturer. Neither my friend nor I had any idea this guy was with different company then, until the week after they filled my attic with off ratio foam, and my home with toxic vapors.  
At Praxair Surface Technologies, it’s our goal to help you get more protection, more customization and more performance from your parts. To do that, we work with you to select or develop coatings based on your operating environment and production requirements. Then we combine advanced preparation services, the right application technology and post-coating operations to create optimal coating performance for any component. Coating Services
Building code regulations typically call for the use of thermal barriers when spray polyurethane foam is installed. The code requires that the foam is separated from any living spaces by a layer of 1/2-inch drywall. As discussed earlier, any material that has been approved as being as equally fire resistant as the gypsum drywall can be substituted as a thermal barrier. Spray Coating
×