Flashing & wood siding around bay window
prairiescl
| Posted in General Discussion on
I built a bay frame and installed 3 Andersen windows. The part under the window is angled as opposed to a flat shelf. The bottom of the angle has a nailer for the the sheathing, so that nailer leaves a one inch wide, or so, horizontal break, ie. the angled sheathing is not a continuous plane to the wall, but stops at the nailer. I can post photos later if it would help.
If anyone has any suggestions or “watch out for…” comments about flashing, casing or siding (bevel cedar) this thing, it would be a big help.
Thanks,
Scott
Replies
Ditto. And keep the file size under 100kb; a lot of us poor country cousins are still on dial-up.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
Yeah, post a photo.
Photos attached. These don't show the windows installed, but are the best for seeing the shape.
Edited 10/31/2009 8:35 pm ET by prairiescl
Make a sill and case the sides. Flash accordingly. Make the entire bottom out of a different material than the siding because it'll be impossible to keep the siding in line if you try and side the angled part. Think bead board with pronounced corner boards on the angles. Screw a piece onto the very bottom for the beadboard to run into. Flash everything.
I would think about making everything out of PVC (AZAK) material and paint it.
The top of the window is up to you.,Or.....
If you know a good tin-knocker and you're willing to go the $$, then do some copper with a seamed top.
Oh....run an apron under the sill too. Don't forget your drip kerf on the underside of the sill.
Thanks for the suggestions. The windows are vinyl clad and protrude about 1-1/4" from the flange. I have a few questions about how the various bits should meet. I'm sorry that this post ran so long. I hope you'll read it, but if you don't have the time, just search for the question marks.
I will use 2x6 cedar to make a sill under the windows. I'll pitch the top edge at 14 degrees (3:12) to drain, but leave about 3/8" flat on top to caulk against the bottom of the vinyl window. The lower edge will have similar pitch for a drip and a rabbet at the back to cover the top of the siding that runs below the sill. How should I mate the sill to the wall trim at the sides of the window? I could have the sill go all the way to the wall and the side trim butt on top of it. This seems more like normal trim in the sense that the vertical trim butts to the sill. Since the wall trim (1x4) is wider than the facing of the 2x sill, the wall trim will have a couple of inches going past it to meet up with the angled main-wall to under bay wall trim. That part will need some fancy angle cutting to mate well with the sill. I could also have the wall trim run down to the bottom of the sill and have the sill butt against it. I think I like this less since it has no natural drainage away from the wall, instead relying on the integrity of the caulk.
I plan to cut a head casing that has a sloped top to match the pitch of the bay's roof. I'll screw that to the face of the bay frame, then screw pieces of 1/2" plywood to form a roof extension down to about even with the top of the window protrusion. I'll route a quarter-round on the top & bottom edges of the plywood, then cover the whole bay roof with EPDM roofing membrane, wrapping it around and under the edge to form a drip. Here, I am inclined to run the main wall trim board up under the roof extension and have the head casing butt against it. The catch-22 is that I need the roof extension in place to mark & cut the wall trim board, but I need the wall trim board in place to butt the head casing against it. I could relieve the head casing to a "good enough" fit with the trim not yet installed, then slide the trim under it once the roof extension is in place. I'll use aluminum flashing under the siding or cap trim between the wall and the bay roof, though I had thought of gluing the roof EPDM right up the wall. Once all that is done, I will screw up a nailer on the bay roof to provide a vertical surface to which I can attach J-channel for the aluminum sofit.
I plan to make "picture frames" of trim for each face of the part under the bay, ripping miters so they meet cleanly. That way, each face will have trim with a perpendicular edge to make cutting the siding to fit an easier job - no compound angles. I'll flash each bay under-wall seam in aluminum, going under the house-wrap at the main wall and over it at the bay wall sides. I'm not sure if I should go over or under the house-wrap on the outer seams - I'm leaning toward over. At the bottom, I'll run the flashing around the bay wall bottom, draining onto the course of siding below. I'll use a few aluminum nails just below the flashing so the heads capture the edge. Do I need to flash where the main wall siding meets the angled trim at the main-wall to bay-wall seam?
Thanks for all the help,
Scott