Confirmation of wall section
I am renovating a 1960’s mid-century house in NY Hudson Valley (Climate Zone 5). The existing wall section is GYP: 2×4 with fiberglass batt: 5/8″ plywood sheathing : 5/8″plywood siding. There is no house-wrap. The house is heated with electric baseboards which I’m replacing with heat pumps.
The inside of the house is in decent shape and I don’t want to remove all the sheetrock except in the kitchens and baths. So in those areas I will replace the batt insulation with Mineral wool and a layer of intello plus and then new gyp or cement board for tile, but in most of the house I will leave the existing insulation in place under the existing sheetrock.
Because we are replacing the exterior siding and the roof here is our plan:
– Exterior wall we remove the existing siding which is in bad shape.
– We will repair any sheathing that is damaged and will add house-wrap, then 2″ rigid foam, then 3/4″ furring placed vertical, then new 5/8″ sheet siding.
– for roof we will remove cedar shingles to the roof sheathing, then add Vapor barrier: Hunter Panel (cool vent) which is 3″ foam insulation with 1″ gap vent gap and then 5/8″ plywood: underlay : standing seam roof.
The house has 2/3 of the roof is cathedral ceiling and 1/3 has an attic, but I’m putting the hunter panel for the cathedral ceiling.
– There is also a section of the house which is cantelieved from a rock and I will add 4″ rigid foam insulation under the floor.
Questions:
1. Any advice on the above in terms of changing the order of the materials or substitutions?
2. Does the 4″ insulation I am putting on the underside of the cantilevered floor need any sort of insect protection or is it fine exposed.
Thank you
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Replies
I think that is a pretty solid plan.
With the 3" (R17) of hunter panels above the deck, make sure that you keep the fluffy insulation in the rafters to R25 or less. Also make sure to block any existing roof vents. If there is a vent gap above the existing insulation in the rafters, either move the insulation up against the deck or dense pack the space.
Exposed foam edges are generally a bad idea because of critters. The best is to box around the perimeter of the foam with lumber ripped to the thickness of the foam and cover the underside with plywood.