Jeff and Joey took us on a River's Bluff house tour this morning. We were looking at small siding details like lapping verses butting and corner treatments. I think we made some good conclusions.
The biggest decision was how to treat the mahogany siding. We've decided to leave a reveal between each piece (instead of lapping). This will create a black strip between each piece. The skin of the house will protect from moisture. Like many green building features, we just liked the look of it, but there are actually good reasons for the method. For example, the pad of air promotes drying.
Here's an upclose photo of a house we saw today:
This is another example of the reveal lines that the a rain screen creates:
So I guess since you are talking rain screen you're going to be going with a manufactured air barrier versus a vapor barrier on the exterior of the house. That's going to be a super air tight situation. In some cases, it's so tight that you need what the industry calls a make up air unit to mix fresh air in with the circulated air.
ReplyDeleteWhat other green building items will you be integrating into the design?
Peter, Thanks for the comment.
ReplyDeleteIn the little I've learned about green building, I actually have learned about the overly tight vacuum problem. Jeff just finished a spec house, which is a prototype (components-wise) for our house. I found a post on his blog for that project where he references this issue:
"With the house being so tight because of all the spray foam insulation, indoor air quality can really suffer as you can easily end up with stagnant polluted air. Pretty much, if you are working with foam, whether it be SIPS, spray foam, superior walls, you have got to introduce fresh air.
We went with a ventilation control that introduces fresh air directly into the return plenum of the air handler. It’s got a damper on it that that is electronically controlled to open at proper time intervals. It also has a temperature sensor and a humidistat, so that it does not open up when it is incredibly humid outside in the summer, or below freezing in the winter. They also make a control that costs about three thousand more that conditions outside air on its way in, which is awesome, but I can’t find anything quantifiable that you will ever make your money back on that. The folks at Oak Hill National Labortories are doing some pilot homes where they are trying to achieve a zero energy home and they are just going with the same type we are using, so I feel fine about copying them."
If you want to read more about this house, see http://latitude38llc.com/wp.