How should I flash these windows?
I'm replacing all of my windows with Andersen 400's, and so far I've completed about 15 of them. I have the flashing technique down pretty well, but those were all on sides of my house with wood siding, that got replaced anyway. So, I had the luxury of cutting back 8-10" of siding around the window so I could flash it properly.
I have 4 windows that I need to do on the brick side of my house. I've been putting these off, but with winter approaching I need to get them done. I know with brick that you can't really flash windows "properly", but I was hoping to get some suggestions for doing the best with what I have to work with.
Please see the pictures below. (Disregard the mess, and the awful mural on the interior wall... this room is just used for storage right now, but we'll be updating it soon).
A few things in particular that I'm wondering about:
- If you look at the close-ups of the side and sill, there are large gaps in the mortar, between the brick and the sheathing. Before installing the window, should I repoint this with mortar to make it water tight? Should I chisel out what's there and use silicone caulk with foam backer rod? Should I leave it alone? Whatever I do to block water, I assume I should do it on the sides and sill but not the top.
- It's hard to get perspective from the photos, but the brick that forms the exterior sill is actually higher than the RO sill framing member by an inch or two. In fact, I will probably have to trim the bottom nailing flange on the window to make it fit, and drive screws at a downward angle into the flange to secure it. In an ideal world, I would bend a piece of aluminum flashing to go under the nailing flange, and channel water to the top of the brick sill. That would pretty much guarantee that all water sheds to the outside of the brick. However, in this case gravity is not on my side. So, any suggestions for how I should flash the sill?
- The side flashing looks straightforward. I'll be using 6" Grace Vycor, and I'll have to trim it a bit but I think it will still be effective. I will try to slide it about 1" behind the existing tar paper. Is there any better way to do this?
- Same thing for the head flashing, except that I'll add a drip cap over the window/under the flashing. When I put up the exterior casing, I'll probably use another drip cap over the head casing/under the brick. Is there any better way to do this?
Sorry for the long post, but there are a lot of technical details to think about. Thanks for your suggestions.