Vent for short peak?

[benzor]

I have a very short peak (2ft long) on an almost square garage.

I'm intending to insulate between the rafters (7in deep available, intend to have air gap) to keep the interior cathedral look, and understand that I should have airflow from soffit vents through to the peak

Interior size is 19ftx16ft. Walls are brick with no other insulation, and I don't intend any insulation in the walls. First goal is just insulate to keep heat load down , but I'd like to later add a natural gas infrared heater for the winter. Location in Boston. If I'm going to heat, it would be 3-4 days / month

Wonder if you have suggestions on roof peak vent style?

 

[yeldogt]

I have never ventilated any roof like that -- fill the cavities and make sure you have a proper VB ... the fully wrapped is nice.

Rood structure dry to the outside as well as walls -- unless you cover w/ ice shield. That should only be done if the roofing type requires. IR: Some metal.

Make sure you come down and keep heat frm leaking out the eave area

 

[benzor]

Thanks for the suggestions!

If I'm filling the cavities, vapor barrier would be interior of insulation, correct?

 

[tfinniii]

The only way would be some collar ties just down from peak with a thru the roof vent.

 

[yeldogt]

You want the VB on the warm side of a heated building w/ people ..... people give off water and heated air holds more moisture. Heat = power. This heat creates a stack effect that drives the air ... so any leak can have humid air going out.

They make encapsulated today that's nice to work with -- and it's protected.

 

[Innovate1]

Was recently told that here in the midwest the recommendation for vapor barrier was totally eliminated about 12 years ago. We have hot summers and fairly cold winters. The vapor barrier is in the wrong place half the year in either location so they decided it was best to leave it out and let things breath a little rather than accumulate moisture in places where it can cause damage.

With that little peak you probably need to cut in some vents just below the peak. Not as nice looking as a hidden ridge vent but I don't know how else to do it.

 

[yeldogt]

Was recently told that here in the midwest the recommendation for vapor barrier was totally eliminated about 12 years ago. We have hot summers and fairly cold winters. The vapor barrier is in the wrong place half the year in either location so they decided it was best to leave it out and let things breath a little rather than accumulate moisture in places where it can cause damage.

With that little peak you probably need to cut in some vents just below the peak. Not as nice looking as a hidden ridge vent but I don't know how else to do it.

Most of what we call a VB is really a retarder ....

The charts almost never show a plastic -- plastic should be avoided. It's used in Alaska.

Also -- when you look at the number of houses using OSB if you use too much of a VB it can cause problems. OSB has wax on/in and does not breath the same == especially with the new ZIP type systems (obviously). This can cause a cavity that will not allow drying.

Buildings dry to the outside and inside -- so when you block one side this can be a problem depending on the other side. Fiberglass will hold water so it's better to retard from a side that may have the most.

Venting is another problem ---- it often causes problems and almost always hurts efficiency.

 

[benzor]

Thanks for all the suggestions!