I am having a "dutch barn" built. The roof has a shallow pitch at the top and a steep pitch on the sides, leaving a vaulted ceiling on the inside. The "barn" is 14x28 feet and the top of the ridge will be about 12 feet up. The rafters are 2x4 on 16 inch centers. How do I ventilate it and insulated it? I have instructed the builder to put a gable vent at each end and a cupola in the center, into which I had planned to put a thermostated ventilation fan. I would like to add insulation later, but don't know how to handle the roof without disrupting the ventilation. The walls are up, but the roof is not, so there is a little time to make changes if needed. Any tips?

[This message has been edited by kdunn (edited July 17, 2000).]

 

Great question, thanks. My house is a Dutch Colonial and I think I have solved my problem. I am interested, however, in anybody else’s insight. Where my top roof meets my side roof there is a transition piece, which is simply a 2x4, covered by another 1x4 piece of cedar stained to match the color of the house. The top roof has an existing ridge vent and one gable vent on one side of the house. I am planning to install small circular soffit vents in the 2x4 transition piece in each 16" rafter space. My insulation will be a bit different than yours in that I do have a small attic and will blow insulation into the 2nd floor ceiling joist space. Hope this helps!

[This message has been edited by gdubes (edited July 20, 2000).]

 

Why don't you just staple R-13 backed insulation between your rafters ?

 

Thanks for the tips. I installed a ridge vent the whole length of the building. I was concerned that if I insulated the top roof with R-13 batts, that would leave no space for ventilation. There is no eave space for soffits, so I am going to put gable vents at each end. Air will come IN through the gable vents and OUT through the ridge vents, right?
I will add 2x4s to form a "floor" to the top roof. That way I have a little ventilated attic with 2 feet of "headroom." The ceiling, though not cathedral, will still be 10 feet from the floor. Should I use 3.5 inch fiberglass to lie even with the top of the attic "floor" joists, or should I use thicker insulation which will lie above the joists? Or something else?

The side roofs I plan to treat the same as the walls. They are pitched about 60 degrees, so I imagine they won't get as hot as the top roof. I will insulate the side roofs and walls with 3.5 inch fiberglass roll between the studs.

Does this sound preferable to simply treating the entire roof the same as the walls, with 3.5 inch fiberlglass for the whole roof and no ventilation other than the ridge vent?

[This message has been edited by kdunn (edited July 30, 2000).]

 

Sounds like a good plan.