I have installed new windows and foamed and caulked them in place. Is there any advantage in caulking the foam on the inside of the window? Would this reduce the effect of negative pressure, and /or improve the likelihood of water infiltration?
Regards
Michael
Replies
What is the flashing detail you used around the flanges? That's how you keep water out. I don't think caulk is useful for window installation--people caulk window fins and think they're waterproofing their install, and it ain't so. Foam can be used between the framing and window jamb, as insulation. You should use foam that expands minimally (Hilti is one maker) or you risk deflecting the jambs inward and binding the sash.
Mike
I'm also at that point. Here's my rationale
Installing from the outside, I caulked the flanges to the exterior sheathing with Vulkum and then covered over that with Grace Window Guard (very sticky stuff), and then ran my #15 felt up over that and caulked each course of shingle over that. All windows..even those with sloped tops, got stainless Z-molding on top.
On the inside, I use foam-rope in the gaps greater than 1/4" and butyl caulk for gaps under that size...even when the window jam contacts the framing member.
This is called OVERKILL even for stormy coastal construction, but hey, I'm going to live there.
BruceCM