Gambrel Attic Ventilation/Insulation

[WalterIV]

I'm looking to finish out the attic/loft space above our detached garage (gambrel roof) and I've got a couple of questions regarding ventilation.  I've looked around on the forum, but haven't found exactly what I'm looking for.  Any help would be appreciated.

The issues:

1.  There are no eaves (so no soffits) and I'm assuming that I need to ventilate the air from the first floor up to the ridge vent (this is the way it is currently working - with no insulation, etc.).  This seems simple enough to me, I just want to make sure there aren't any issues with this set up that I should be aware of.

2.  The upper & lower sections of the roof have a beam dividing them.  Is there a way to provide ventilation around or through this beam?  

Thanks,
Walter

[PEG688]

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The issues:

1.  There are no eaves (so no soffits) and I'm assuming that I need to ventilate the air from the first floor up to the ridge vent (this is the way it is currently working - with no insulation, etc.).  This seems simple enough to me, I just want to make sure there aren't any issues with this set up that I should be aware of.

2.  The upper & lower sections of the roof have a beam dividing them.  Is there a way to provide ventilation around or through this beam?  

Thanks,
Walter

  #1:  Not really , it's not to vent the first floor .

 The venting you'll need will be the rafter bay , above the insulation .   You'll have issue if you need to meet code , or wish to get max insulation in those cavities .
    What are the rafters ?2x12, 10 , 8 , 6 ??

  Althought it cost more you may be better off long term with a invented attic / loft by using a foam / spray in insulation that is made for just what your doing/ hope to do .

 
 Iso some thing some thing ,  here's a link :

 ://www.advancedinsulationinc.com/sprayfoam/default.htm


 Unvented Attics with Cathedralized Half-Pound Foam Insulation

 The problem with conventional attic insulation is that attic vents used in conjunction with recessed lighting fixtures and other penetrations through the sheetrock ceiling create an air leakage path from the inside of the house to the outside, and visa versa.    
 
At Advanced Insulation we believe a state-of-the-art home built in an extremely hot climate should have an unvented attic with half-pound foam insulation installed on the underside of the roof sheathing. This technique is known as an unvented attic with cathedralized insulation. In this section, we will discuss half-pound foam insulation and unvented attics with cathedralized insulation in depth

 

 #2: You could bore a couple of 2" holes up high if you use regular insulation , in each rafter bay to provde a venting path.

 You'd still have to figure a way to let outside air in the bottom of the bay  :-/ :-/

 I'd suggest you check out the spray in type you'll get more insulation R value MTL , and not have to find a way to vent it.  

[John Raabe]

There have been a number of discussions on this over the years in the old and very old forums. Don't think it has surfaced here recently.

Here is a diagram I drew up to explain some of the venting issues of this roof system and how it might be built easily.

http://www.countryplans.com/Downloads/Gambrel.pdf