QOD: What’s the best way to Insulate the underside of a roof?
Tom asks: “When spraying the underside of the roof, should I spray directly to the roof deck or install baffles to leave an air channel?”
Great question!
When spraying the underside of the roof, you have two options:
- You can spray directly to the underside of the roof deck and seal off all roof venting.
- You can put the baffles between the rafters to create an air channel from the soffit to the ridge vent and leave the roof deck vented.
Before deciding which way to go, we’d recommend checking the warranty on your roofing materials, including the shingles. Some shingles are made to withstand the extra heat that will be kicked back to them by the foam and some are not. You may void the warranty on your shingles by spraying right to the underside of the roof deck.
Another factor you’ll want to consider is whether or not you feel any of the roof sheathing will need to be replaced in the foreseeable future. If you have an older roof that may be in need of some repair down the line, then installing the baffles is probably the best way to go. With this option, you’ll be able to replace the roof sheathing down the road without having to replace the foam.
For even more detailed information, check out the attached short video. Here, Ashley discusses the use of baffles, and why you may choose to go one way or the other.
Do you have a roofing project that we can help with? Every project is little different, and we are happy to answer questions you may have regarding your unique situation. Just give us a ring at 800-516-0949 and we’ll hook you up with helpful info, and the perfect solution for your project!
