Insulation Issue

[John Allingham]

These shots are from the attic of a five year old home. In one area, the fiberglas has been blown back by a gust of wind through the perforated aluminum soffit vents.
Obviously it needs to be redistributed, but if this was your home how would you prevent it from happening again?

[Larry D. Kage]

A gust of wind, from the soffit, should be directed up the proper vents (chute) and toward the ridge vent.

I can't really see the top of the exterior wall between the trusses but, often, a piece of batt insulation is stuffed there between the top plate and cardboard proper vent. Or, there are cardboard proper vents that sit tight to the exterior corner of the top plate to seal the soffit off so insulation doesn't fall into it.

In your case it appears the air is not directed up the chute but, instead, blows on the insulation in that bay.

[John Allingham]

Hi Larry
I think the bay with the chute is working properly. It's the next bay over that's blowing. I like your idea of stuffing fiberglas in to prevent blowing.
I have seen fiberglas batts in the location you suggest in other houses but I always figured it was just to keep the loose insulation out of the soffits. I guess it serves two purposes.

[Brian A. MacNeish]

Originally Posted by jallingham

Hi Larry
I think the bay with the chute is working properly. It's the next bay over that's blowing. I like your idea of stuffing fiberglas in to prevent blowing.
I have seen fiberglas batts in the location you suggest in other houses but I always figured it was just to keep the loose insulation out of the soffits. I guess it serves two purposes.

Stuffing fiberglass into the rafter/truss cavity at the top plate throat is one of the worst shortcuts going on in houses. The fiberglass batts are not air barriers. They may stop excessive wind blowing loosefill insulation around but they don't stop cold air infiltration through them and maybe down near the top plate where heat is stolen by the moving air.

The wax coated cardboard combination end baffle and air chute are a good solution if.......installed properly.......there's that old recurring problem again.......quality workmanship!!! The best way to solve that problem is at the framing/sheathing stage. Extend the sheathing to the top of the butt end of the raised heel truss so it forms a solid air barrier and directs wind up over the insulation.