Reyesinspctions.com (Robert Flaa) inspected a new house yesterday that the roof was foamed to a depth of over 6 inches. It was sealed to the outside air with a door in the attic over the garage to get into the sealed area over the living area. The living area ceiling did not have any insulation other than the foam on the roof. I kind of like the idea of seeing everything wiring, gas pipes (black steel), water lines (yes the house had pex water lines in the attic that were insulated), duct all the way to the sheet rock, drain lines, vent pipes, ETC without blown in insulation covering everything up.
I have inspected this type home before and have my doubts as to the total effectiveness of this type of home. But never really thought much into the overall design of this type of home and the longevity of the building materials used and the effect that one has on the other.
With over 30 years of experience in construction from home building to restaurants and now 8 years of Home Inspections. My thoughts go to the roof and how good this is for the longevity of it. In the past I have inspected a home that the seller said the roof was 7 years old and after going on the roof to inspect it. I found the roof to need replacement. Upon further evaluation of the home I found there was no attic ventilation None. I concluded that the roof was cooked from both sides and premature failure was due to the lack of ventilation on the underside. I recommended that they have the roof inspected from a reputable roofer from that area. He concluded the same as I did or reconfirmed my findings and the buyers found that with all the other issues with that house and the time it would take to replace the roof was to much for them, so they backed out of that home having me inspect another home in that area for them.
This will be like all the other new building materials that I have seen in the past like masonite siding that failed miserably and practices that have ether failed or succeeded in the past over time, only time will tell the story.