Dutch hip
ld_lm4| Posted inEnergy Efficiency and Durabilityon
Through reading your articles I understand that simple roof lines are best for vented roof systems. Is there any way through design that a dutch hip could be incorporated? My thinking is the dutch hip would be good for shading of the windows, maybe have open sofits for a clear path of a vented roof system. This will be a one story home.
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Replies
L.D.,
First of all, can you tell us your name? (I'm Martin.)
It's possible to vent a hip roof, including a Dutch hip, but it's hard to do it right. The best way it by double strapping the roof with 2x4s on the flat, followed by a second layer of roof sheathing.
The first layer of 2x4s are installed above the rafters -- that is, perpendicular to the eave, either 16 inches or 24 inches on center. The second layer of 2x4s is installed perpendicular to the first layer, usually 24 inches on center. This allows ventilation air to move sideways as well as up.
Of course, you'll need soffit vents as well as ridge vents -- or, at the Dutch hips, top-side vents designed for the intersection of a shed roof and a wall.
It's complicated and expensive. There are cheaper ways to build a roof.
Martin, Hi my name is Lawrence. We are post Hurricane Harvey rebuild. I am not a builder nor do local contractors build houses with high energy efficiency. I will be acting as the general contractor using high energy efficient systems. This area gets an average of 55” of rain per year, it’s humid and southeast of Houston. I am looking for a system to where we can incorporate porches for entertaining and shade from the sun and repelling the rain from the walls. I would like to do this on all four walls. Any thoughts and information are GREATLY appreciated.
Venting the exterior side of the roof deck isn't the same as venting the underside, since the structural roof deck is fairly vapor retardent until it's moisture content is already high (the very condition you're trying to avoid with venting.)
Dana,
Clearly. Which is why L.D. should probably choose a vapor-permeable type of roof sheathing (for example, old-fashioned board sheathing) for the lowest level of roof sheathing if L.D. goes this route.
Are you asking about creating a vented attic or a vented cathedral ceiling? It's not 100% clear from your initial post, and it might influence the sorts of responses you get.