Insulating Garage - Wind Block Under Vent Shutes?

[ED26]

In process of insulating garage with fiberglass batts - R30 unfaced (perpedic) on top R13 faced (parallel w truss)

Put up the duravent rafter shutes and extended them past the top plate a few inches (4-6") into the soffit area

Question: My plan was to cut pieces of the fiberglass and stuff it under the vent shute/above top plate and a few inches past it toward the soffit...if that makes sense.

Doing some research I discovered wind wash effect, appears some folks create a 'wind block' out of say, rigid foam pieces cut then spray foam them into the cavity.

Wonder if it would be worth the extra effort to do so? Or just tuck the fiberglass in and call it a day.

If I create a foam wind block, would it be wise to use , say 1" foam pink board, or buy some more duravent and vent a piece to fill in the gap between the top of the top plate and bottom of vent shute??

 

[Kaizen]

If you had r13 batts I might say it’s worth it. Thick ones I wouldn’t bother. Imo only important thing at this area is seal it if you are blowing insulation so it does not fill soffit.
In my area I would use a great vapor barrier in that situation as well. Installed right it makes a great air seal so the air will flow through venting not the air leaks


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[ED26]

i am not blowing in insulation, just using the fiberglass roll/batts.

Should i just use some r30 and stick it over top plate, maybe a inch or so past into the soffit area

 

[wrenchguy]

A thin draft stop would best, r30 beyond plate would be ok imho.

 

[ED26]

the distance between top plate and bottom of vent shute is between 3-4"

1) I would go with some pink 2" foam and cut down to 3" and place over top plate - foam it shut (like this image)


2)take some R30 unfanced and slide it past top plate, maybe 2/3 inches into soffit space, in theory creating a plug of some sort

Option 1 is a lot more work, but may be worth it?

 

[The Cobbler]

I used 1/4 luan underlay & made my own baffles that went from truss to truss, and I stuffed fiberglass into teh space between the top plate & baffle . while not 100% air restricted, I think it's good enough.

 

[ED26]

I used 1/4 luan underlay & made my own baffles that went from truss to truss, and I stuffed fiberglass into teh space between the top plate & baffle . while not 100% air restricted, I think it's good enough.

I used the cheap duravent chutes from HD..

at the point where am ready to finish the edges and idk if it would be worth the pink foam effort to try and foam those tight cavities


Or just do like you did and stuff insulation beyond top plate

 

[banjopete]

How expensive is your heat source? I also went with the duravent pieces and just filled the space over the top plate with fiberglass insulation. In my case it's just a garage, I'm in a proper cold zone and keep the garage above freezing year round. I'd be surprised if going all out and really sealing that gap would make much difference in my costs. I weekend warrior on projects mainly but I don't pay much more than $25/mo to have a warmed garage all the rest of the time for the cars.

I guess it's a long winded way of saying how much to you care? And that i don't think this is a critical element to the insulation job considering all the other choices with much more area in question.

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[Kaizen]

This is your garage right? With a roll up door you will always have leaks.
You seem like you want to do the foam so go have fun. Gonna go through some material. Not cheap material.
Won’t hurt but I don’t see the need with that size batt


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[ED26]

Yes it’s a garage with 16x7 insulated door.

I’m at the point of finishing the edges and wanted to see what folks are doing for the eves.

Foam board is $30. Cut it in strips and spray foam it in. Not a big expensive but some time investment.

Maybe more practical for a living space?

 

[Bert_]

I've folded and tucked paper faced insulation in there. Not as good as a solid piece and gaps filled with expanding foam but at least it stops a majority of air movement through it. Bare fiberglass does nothing to stop air movement.

 

[TractorJeff]

FWIW: I put 2x6 blocks in and installed the chutes prior to laying the roof sheeting down. then went inside and stapled up to sheeting.
Only thing I would do different if I could would be to pre-position all my insulation right there at the edge. On a low pitch, you have no way of getting any extra insulation in there once the ceiling and roof sheeting are done.