Monday, December 28, 2009

Roof Details

Back on roof work, we put in the proper chimney pipe now. We had purchased some 8" inner diameter piping when the roof guys were setting it up, but we've since decided we wanted 6"id pipe. Since the roof got built before the fireplace/stove was in, we had to do some backwards building to get this right.

Above you can see the shiny double-walled chimney pipe sticking out of the ceiling. Since the roofing is already on, we had to build those wooden brackets in on the ground, screw the flanges in to the top of the pieces of wood, and then get the whole thing up in there tight.
We actually used pipe clamps, between two rafters as extra holders, so that we didn't have to struggle to hold the thing up there while screwing it in.
Here you can see the vent hole we cut in the cross bracket wood, to allow air to flow from the soffets (outside vertical edge of the roof) all the way through to the vents at the peaks.
An important part of this was that we didn't want the chimney pipe area open to this air flow, in the unlikely event of some sort of fire, you don't want the house itself to be breathing the fire along the roof. Thus, we kept the holes just in these areas, that will not be connected to where the chimney is.

We're also working on putting in the soffets - wooden blockers on the outside edges of the roof - and here you can see the vent holes (with screens over them for bugs), also part of the roof cooling system.

In California, they don't really do this venting much, even though it's a great way to add insulation to your roof, to let hot air flow through and out, as it can pull forest/house fires into your roof structure. However, because we have inflamable walls and will do careful landscaping around the outside of our house, we decided that this could benefit us.

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