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TOPIC: General Discussion

Barn Roof Question

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We are building a new barn with a Gambrel style roof. The botton drop is very steep - it's probably more than a 12:12 (I may have stated that incorrectly - it's steeper than 45 degrees - rises at least 12 inches for every foot it goes horizontally). Anyhow the installer did not use transition flashing where the steep parts intersects with the top section. Is that a problem? He says no and that it's steep enough that it should not leak. Also, we are installing this over purlins. They are putting a bubble wrap overtop the purlins and under the metal. Will this stop sweating? I'm not sure but it looks like they have pieced this bubble wrap in places and where they have terminated it in a few places they fell short of covering all the wood - in other words, in places the metal will lay on the untreated purlins. Will that be a problem with sweating, etc. The barn will be unheated and their should be plenty of are flow - the top of all the walls are open under the rafters. I am worried about water damage. Should I have concerns? Thanks.
Guest User

11/24/2007
First of all, what you have is a rather unique application in regards to those of us whose focus is residential. Ideally, yes, there should be a pitch change flashing. Unfortunately, it is a little late now. Unless the bubble wrap is completely sealed, moisture will get by it, get trapped, and condense on the back of the roofing. How often this happens depends a lot upon exact weather conditions and whether there is any moisture being produced inside the barn. Todd Miller
Todd Miller
Isaiah Industries, Inc.

11/27/2007
The barn will be unheated and should have plenty of ventilation. However, with animals, there will be moisture. The stalls will have dutch doors that will be open most of the time. In addition, the main barn doors will be open probably 90% of the time. The inside barn temperature and humidity should be close to the outside temperature and humidity year-round. Will that help?
Guest User

12/5/2007
you should have no moisture problems from animals with that much ventilation.
Guest User

12/22/2007
The goal would be to keep the inside as close to the outside temp and humidity as possible. When the inside becomes warmer and wetter, though, you will be asking for condensation. Todd Miller
Todd Miller
Isaiah Industries, Inc.

12/29/2007