We have an older house (approx 100 years old). The previous owner replaced some of the windows with vinyl Kohler retrofits. The old wood windows were removed and the new retrofits are essentially just butt up against the back of the existing siding/trim and do not have a nailing flange.
I will be adding a layer of insulation, strapping, and new wood siding. My issue is tieing in the new tyvek/flashing to the vinyl windows. I’ve come up with two schemes, and would like some opinions (or alternatives).
Option 1, metal flashing below the header trim. This is the easiest to install but I’m worried there isn’t enough space between the return and the trim to allow for proper drainage.
Option 2: metal flashing above the header trim This is a bit more difficult as it requires cutting the insulation and strapping to allow for the metal flashing to pass through.
Replies
Keep in mind that nailing flanges are a relatively recent innovation (ca 1980). Before that, aside from head flashing, the trim or siding would just butt up against the windows and be caulked. Not perfect but it worked. You can improve somewhat by carefully attaching flashing tape or housewrap to the sides of the window jambs.
shaz
I changed the setting on your profile-you might be able to add those pics now.
Best of luck.
Thanks Calvin, I updated my original post with photos.
I'd suggest having a bit more wood to have something to nail the trim to. When extending window openings like you're doing 3" of solid wood around the opening is my normal - glued and screwed so it's a solid surface for trim, windows, or whatnot. While the extra insulation around the window appears good at first glance, trying to get the trim anchored securely will be a challenge and I'd suggest against your first flashing option because the jamb extension and window trim can't be nailed to each other (makes a dam for water if it's coming down the flashing.). Also keep in mind you need continuous nailing around the window for your siding - never a good idea to have siding just floating, so there's some more wood - essentially you'll end up with a great deal of solid wood around the opening as a practical matter.
Moving the windows out further in the opening normally makes them easier to trim to and keep water out, although I enjoy the looks of a traditional window so do what you like the looks of and if your details are done correctly either will last. The way I essentially extend the framing of the rough opening allows the window to be placed as far out or in as makes sense in a specific situation. It also allows me to trim out the window as I would with any other normal rough opening so I'm not making things up as I go along for each situation.
It looks like a great upgrade for your house!