Insulating a scissor truss

Hi all. Looking for opinions on how best to insulate a scissor truss. The attic in question will have have energy heel trusses with a bottom pitch of about 3/12; Soffit and roof vents with baffles. I'm concerned that just blowing insulation will end up with less than optimal insulation levels at the high point of the ceiling, from both gravity and wind wash. I've heard some idea of encapsulating the insulation? Any thoughts? Thanks.

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  • Just curious how you were going to encapsilate the insulation

    Baffles should take care of wind washing - gravity also has to deal with the rule that an object at rest tens to stay at rest but if worried & spraying celulose they have some that can be sprayed with a binder though I am not sure how they would spray that attic. Considered a hot roof system?

    • Encapsulate is perhaps the wrong word. The idea is to use netting over top of the desired insulation thickness to avoid the gradual drift downwards of the insulation. From what I've read this is essential for bottom pitches beyond 4/12, so I'm not sure how necessary it is in this scenario. That's the advice I'm lookng for.

      And I definitely agree that baffles prevent the worst of wind-washing... but not all. Some wind-driven turbulence will occur in the open space above the insulation. I'm just not sure at this point how significant it will be and, more importantly, how much it will affect the insulation on the higher reaches of the slope.

      Also, not a hot roof system. That would mean insulating the underside of the roof deck. I'm not doing that.

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