# Insulating Bonus Room Roof



## m6465 (Apr 25, 2011)

Alright, newbie here. I was planning on this being a pretty straight-forward project until I got in the bonus room and started looking around. I'd like to finish off the space and was planning on using baffles stapled to the sheathing and then placing fiberglass on top of that to vent it to the ridge vent. One problem ... my modular home company built two sections of the roof pieces (the front one and the rear one) with horizontal rafters meaning I can't place the baffles to vent it vertically to the ridge vent. 

Any suggestions for handling horizontal rafters? On each side of the sections with the horizontal rafters are vertical rafters where I could vent to the ridge vent, could I vent horizontally then drill some holes? 

I could post a picture if that would help ....

Any pointers are appreciated. Thanks.

Mike


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## AGWhitehouse (Jul 1, 2011)

m6465 said:


> I could post a picture if that would help....


Yep...


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## m6465 (Apr 25, 2011)

You can see from these pictures that the center section has horizontal rafters, with vertical rafters on either side. The front of the house is fine because there is a dormer with a window and I have vertical rafters leading to the ridge vent. Picture one shows the middle section with a glimpse of both sides, picture two is a close up of the right side.


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## AGWhitehouse (Jul 1, 2011)

You can put the baffles in the vertical rafters to the right, but the center section will need to be a "hot roof". Just fill the bays with insulation.


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## heybales (Aug 25, 2011)

Holy cow, those only look like 2x4's coming up the roof angle, and then 2x6 on the horizontal! Now, my size perception is terrible, but still.

What area of the country is this in?

Is there insulation in the floor for rest of the house, or what is in the ceiling here is really what the whole house gets?

There is a method of insulating the roof deck with out venting, making the whole attic part of the conditioned zone, which would apply in this situation. Possibly skip the venting and benefit more from that extra insulation.
Usually includes using the silver radiant barrier and shingles colored lightly for less heat gain issues, and using spray foam for maximum R-value when you have such little space.

But you may live in a temperate zone and don't need much insulation.


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