How high above my attic insulation should my ventilation be?
New build, mid construction, I have raised heel trusses which measure around 18 inches to the underside of the sheathing and the plan is to have 14 inches of cellulose when settled, so around 16 inches when fresh. I’m leaving a 1.5′ opening for ventilation right now, with some bug screen stapled over to prevent material loss during installation. Martin’s articles suggest I’m fine with a couple of inches of clearance above the insulation prevent wind washing, but Hammer and Hand’s best practice manual suggests a minimum of 12 inches, and many of the site built baffles I’ve seen pictures of terminate much higher above the insulation. If it matters, my overhangs are 3ft. Is it worth building baffles to terminate the ventilation higher, or a waste of time?
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