Large arched window

This project was one of my most challenging, since I had not previously worked on a house that was built using balloon framing.

The house had been moved and installed on a new foundation about 25 years ago, so, I knew the foundation was good and easily accessible. This allowed for jack studs and new studs that would hold up the new header to be installed without any breaks to the foundation. Solid, firm bracing for the new header was very important.

My next challenge was how to keep the studs above the window up while I removed the old studs and the old window to make a larger hole in the wall. Normally, I would build a temp wall inside and hold up the effected floor joists above, which would be enough to allow me to remove and re-install. With balloon framing, I couldn’t take the chance that the joists would be attached in a way that would hold up the wall, as the studs go from the foundation to the attic, no floor in between to break it up. The floor joists are just nailed into the side of the stud with a bracer underneath, also nailed into the studs.

I chose to use an outside header to accomplish this. I went with an 8’ 2×12, lagged it into each stud, strengthened it by screwing another 2×12 to it. This held up the wall as expected and allowed me to remove all I needed to.

Also, the header was going to intrude into the second floor, where there would normally be a rim joist and floor joists, but this house didn’t have those. Still, I had to install a double 11 7/8” LVL header. This is overkill, I know, but I would rather be safe than sorry.

My next problem was the window itself. It was supposed to be a replacement window only. Built to slide directly into an existing frame, not made to be installed on it’s own.

I had to install aluminum nailing flanges on the sides and one small one at the top. I used silicone to attach it, then screwed it to the sides, to keep from having a leak. This seems to be a good way to do it, as it went in without any issues, other than it was very heavy.

Of course, I used flexible J channel to finish the outside, so that was pretty easy, and then replaced all of the siding.

The homeowners have decided to trim it out themselves on the inside, which, I am actually thankful for.