Conditioning an existing attic in a 1900s Queen Anne wooden home
conditioning an existing attic in a 1900s queen Anne wooden home.
Location: coastal South Carolina
two story wooden home built 1901
attic dominations: 22’x46’x(10’at peak of roof)
planed usable newly conditioned attic space 10’x46’
2 gable end vents & ridge vent.
no gable end sheathing or sheathing on first or second floors.
roof is a standing steam installed over asphalt shingles.
rafters are true 2×4 and roof decking is true 1×6 tongue and groove.
HVAC for upstairs is located in the attic with duct work through ceiling of second floor space.
reinforce floor in attic with 2’x12’s joist because of 14′ span to middle load bearing wall in 22’x46′ size attic.
spray foam with open cell 4” between rafters and 4” silver glow insulation on gable ends.
Close 2 gable end vents with glass.
Sheetrock walls gable ends and carpet entire attic floor.
The access to the attic is a new staircase that has no door and will leave attic space open to second floor.
We plan to replace exiting gas furnace with 3 ton split unit heat pump that will be located behind knee wall in attic. The return will remain in second floor stairwell and vents will remain for 2nd floor and be ducted between 2’ x12’ floor joist in attic with additional vents for attic space.
Not sure what to do with ridge vent? Should we spray foam over and just sheet rock at coiler ties, leaving 4” space at ridge and vent?
Should I use open cell or close cell spray foam and do you see any other possible problems with my plan to condition attic space?
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