Surprise Roof Replacement and Beefing up Insulation
Six months ago, I bought an old house in Western Mass (Zone 5a). A week ago, I noticed a sinking area in the roof just below a skylight. None of the repair options were satisfactory so I plan on replacing the whole roof (see roof details for more). I’ve found a good roofing contractor that will rip two layers of shingles off, replace bad planks with plywood and add a vented roofing system.
Please help me to understand if improving the insulation should be done in conjunction with this work or if it can be done later. Because of the sinking section, time is of the essence.
Cathedral ceiling, unvented. AFAIK the decking is the old (original?) planks. Two layers of shingles, with current layer put on 17 years ago. I’m not sure what the insulation situation is, but it’s not great. I’ve seen evidence of exposed pink fiberglass but I’m not sure if the thickness is only the depth of a rafter or has been built up. The previous owners were very eco-concious but not well-heeled.
One idea is to rip off the decking, have spray foam put in from above, and put new decking and roof over that. This would be a substantial enough change to the current plan that I may need to find a new roofer. It would also take time to coordinate and I probably can’t afford it.
I’m also thinking I might just have the roof replaced and improve the insulation and air barrier on my own from inside. I would expose the rafters, cover them with foam board, and put new drywall over it. Probably do it one room at a time and use recycled insulation over the next year or so.
Thank you for your help!
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