|Posted on Wednesday, July 06, 2005 - 11:19 pm: ||
I've got an old house with a standard gable roof and a small addition with a gable roof 90 degrees from the first one. This past winter I got some pretty serious mold in the attic over the bedroom that had a humidifier running all winter and some mold at the other end of the attic over the shower.
The ceiling joists and the rafters are roughly 2x6 and the ceiling currently has some old blown in insulation but it's settled out to be pretty darn thin.
So I'm in a quandry as to how and what to insulate and what to do about venting the roof.
I'll be cleaning out the existing insulation soon to make it easier to rewire the second floor. I was planning on just blowing new insulation into this space but how can I get a vapor barrier below the insulation without ripping my ceiling down? Even if I just blow the new insulation in, there is a pull down stair at the top of the first floor steps so all the heat just goes up the steps and right into the attic anyway.
Insulation the rafters is an option but far more difficult because there are no walls to hold insulation, it's just plank board. Plus, if I put in an air gap, there isn't much depth for insulation unless I skin the rafters down and loose what little height up there I have. last but not least I may blow the whole roof off for an addition in four or five years making a lot of extra work for myself.
Hope I didn't make this too long but even as it is I'm sure I left out some important details. I go back and forth every twenty minutes on which route to take. Currently I'm thinking to put roughtly an R13 in the ceiling and go ahead and insulate the rafters as well. This would allow some heat to go up into the attic but the rafters could have a good vapor barrier to stop the moisture, raise the overall R value and give me a pseudo heated storage area. That's a hell of a lot of work though.