Replace old window with smaller window

[suncrest79]

I just posted a question concerning replacement windows for my 1979 Suncrest Mobile Home. I decided to post this separately as it is a special "must do" project that is more complicated.

Basically I want to reduce the size of my kitchen window. I want to bring the bottom up about 7". For some reason the bottom of the window is only 37" above the floor, making it only 1" above the countertop exactly where the sink is located.

I just gutted my kitchen and have new cabinets and countertops to install. Because the window is so low right now the 4" backsplash on my old countertop was actually cut out at the window. As strange as it sounds, I'm pretty sure this is original. Maybe the previous owner installed a new countertop, but I still can not comprehend why the home was actually manufactured this way. Why in the world would they place the kitchen window only 37" above the floor in the kitchen. lol. But this is beside the point as I am now forced to deal with the issue.

Just to give a little more background, when I gutted the kitchen I also removed the walls in back of the cabinets and replaced everything. I rewired everything, then install 1/2" thick green drywall. At the window opening I cut the drywall opening 8" above the bottom of the window, so I am all set with that part at least.

Because of the length of both walls I was able to avoid any joints showing up, so even if they start cracking it will be below the backsplash of the countertops and should not be an issue.

Anyway, my basic question is what is the best way to replace the old window with a smaller window?
The best solution that I could come up with on my own was as follows:

1) Build the bottom up by screwing additional 2 x 4's to the bottom and sides of the existing window frame 8" up, then have a 2 x 4 running across the top as the new bottom. So basically I would be building a "box" of 2 x 4's to create the new bottom of the window.

2) Then, on the outside I could install additional lap siding by sliding it in and securing it to the 2 x 4 "box" that I built.

3) I could then secure the new lap siding to the existing siding with liquid metal, which I used very successfully to seal some holes last year. This "should" make it waterproof on the outside if done correctly.

4) Finally, I could install a nice box planter on the outside to cover up the bottom. I would do this because while I think I could make the transition from new to old siding waterproof, it will probably not look very nice.

As far as the additional lap siding is concerned, I am luck enough to have some from some shutters I removed that are made out of the same material (lap siding).

So does anyone think this is the best way to do this? Does anyone have a better way to do it?

Any advice would be GREATLY appreciated. As I already said, this is pretty much a "must do" project, so I have to figure out some way to do it.

Thanks - Joe

[JD]

Hi Joe,

Sounds like a good plan to me. If there is not change in the existing framing and it is good shape, it would have not be changing the original engineering. I would still add the cripple studs in the middle of this box to maintain your 16" centers. Also if I was building it, I would attach the side and cripples to the bottom 2x4 and attach that to the existing bottom of the rough opening, and then nail the top 2x on. This would give you a straight shot to attach the bottom 2x to the existing framing and maybe get a better shot to the nails going into the sides.

I am not familiar with the liquid metal product. Regardless which sealant you use, I would cover this added framing with a vapor barrier. It would be best to pry the siding open a little so you could get the vapor barrier or back into the wall 3-4 inches, and then seal to that. Also, as long was you are putting a planter box there, some Z-bar at the bottom of the added siding would be great protection and a good seal.

JMO
JD

[Brenda (OH)]

this may be helpful,

take the 2 x 4s and build a frame around the replacement window. slide the window out, and then install the perfectly sized opening of the frame into the wall.

doing it this way may eliminate some of the shimming around the window, the shimming now goes to the outside of the frame.

Brenda (OH)

[Jim from Canada]

I think you have a good handle on the framing of it. As long as the original framing is all intact, it should be OK. What I would do, is cover the exterior of the framing with a piece of plywood, then take Ice/Water shield, attach to the interior vapour barrier, over the bottom sill of the window framing, and continue it down the outside, over the plywood, as far as I could go. Then, do the same for each side of the window framing, making sure the corners are well sealed. Then, get some aluminum flat stock (for fascia) and bend up a drip edge that goes from under the new window, and down the front exterior, with a lip that goes over the existing siding. This will go behind your window box you mentioned. I would leave a gap between the window box and the aluminum so water does not sit there. Do not forget to put a drip edge above the window too. These can be bought pre made.

Jim