||09-21-2010 01:13 PM
Proper way to flash exisiting windows when installing new fiber cement siding, plus..
Hey all. Great site. I've been lurking a while now. Before I get to the obvious question, a bit of background with this current house project:
1915 kit home bungalow with wood siding. No sheathing. Interior previously remodeled, fiberglass insulation/dry wall. Behind siding is 1915 thin tar paper manufactured with holes in it (yea, I've never seen it before). Since the ext walls are straight and the siding is flat (beveled edges, however), the plan is to leave the siding in place (well, I have to as it provides shear strength), remove all trim boards, NOT sheath it with OSB or anything, wrap with 30# felt, fiber cement siding and LP trim boards. Since the 1915 paper certainly breathes with the holes in it, I'm not concerned about trapping moisture between the outer felt and the inside felt (but that's for a different discussion if needed). My concern is flashing the windows. The windows were previously installed vinyl windows. I'm going to assume they were caulked under the nailing flanges and installed correctly (at least I'm hoping that's what I'm going to find). So the question becomes how do I treat these existing windows? I'm not going to be pulling them, so I'm thinking flash the windows with self-adhesive flashing to start, (over the drip cap), and felt over that (top to bottom of course), caulking as required, trim over the works. But, now I'm starting to question that plan. I think the above would work well to keep water from getting into the walls from around the windows, but the LP trim might be at risk even if caulked. Perhaps a dip cap over the top trim piece? So, any thoughts on this would be greatly appreciated. Grumpy, I bet you have a workable solution. Thanks!!