|Posted on Thursday, January 05, 2006 - 01:59 am: ||
I'm new to slate, but am looking forward to working with this material. I have read the Slate Roof Bible (over and over. My wife is starting to complain...) with great interest. A great book. A lot of information, presented in a way that is easy to understand and absorb.
I'm designing a new house and am planning on cutting and milling the sheathing from oak trees on the property and installing the slate myself. Following the recommendations in the Slate Bible is straight forward. Recommendations for rafter size, spacing, materials, and pitch, have worked their way into the design. But I'm missing a few things.
Here in Oregon, the building site is exposed to weather and gets a lot of wind-driven rain for 6 to 9 months. The house will have gable ends exposed to the weather and am planning on an 8:12 pitch.
Is there a minimum recommended eave length? I'm looking at 2 feet from the wall. Too much??? Not enough??? Just right???
The Bible recommends that the slate overhang 1 to 1 1/2 inches over the gable end. With weather coming at 45 degrees into the gable, I think some of it will be driven under the slate, and between the slate and sheathing, Is there any value in having the slate project more than 1 1/2 inches? Or is flashing a better solution?
|Posted on Thursday, January 05, 2006 - 10:26 pm: ||
The farther the slate projects, the more there is that is unsupported and available for (for example) wind uplift (and other forms of destruction such as ladders). I don't think you have to worry about water being driven under the gable end slates. We have terrible rains here at times in western PA, but the standard slate overhang on gable ends has been 1" for well over a century with no water infiltration problems. I don't see how flashing will help either on a gable end. You can't seal up the gaps between the slates (nor do you need to).