House remodel, insulation questions
Hi, I have read a ton of the articles and forum posts on this site regarding insulation and conditioned attics. I am currently in the process of renovating a 1960’s 1 story ranch with a full basement on the border between climate zones 5 and 6. I am at the point where I need to figure out my insulation.
The house is gutted to the studs and its going be run off hydronic floor heat in half the house and hydronic ceiling heat in the other half of the house (basement heat is probably going to be radiators or hydonic walls). I have a 4/12 pitch, hip roof with 2×6 rafters. The entire drip edge of the house is vented with several vents along the roof top near the ridge. The house has never had air conditioning and I want to put the air conditioning in the attic because I am not willing to give up any of the already low ceiling height in the basement. I am most likely leaning towards a ductless mini split system or something like the unico system (high velocity ducts).
I have had quotes for high and low density foam and cellulose. I really would like to condition the attic space and airseal it tight but I have a really hard time messing with a system that has been used for a very long time and it works well (unconditioned attic). I have paranoia when it comes to the idea of rotting roof sheathing because of the lack of drying potential if you put foam on the bottom of the sheathing.
Am I better off blowing in 16″ or so of cellulose after air sealing the attic floor? or should I be looking at closed cell foaming between the rafters? If I do the cellulose, I will be putting baffles in that extend from the space between the roof sheathing and the top plate, up a few feet in the rafter bays to get air flow above the cellulose. The house will have lots of can lights (maybe LED wafer type) and areas where air can make it through the ceiling into the attic space above. Should I be going around with a can of foam and sealing off all these air gaps? Is there a faster way to air seal the entire attic floor?
Thanks for any input
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