Window Replacement

[FarmerPete]

I'm in the process of remodeling my garage. As part of that, I'm down to studs on all of the exterior walls. I'm planning on covering the wall up with OSB once I have the electrical and insulation installed. One of the walls has two old 3'x3' aluminum windows. I was originally planning on leaving them, but one of them appears to have leaked a bit and the sill is looking pretty black. I figured this was as good an oppertunity as any to replace them. I've replaced an exterior door before, but I've never replaced a window. I don't see any screws holding the current window in, and I'm concerned with damaging the vinyl siding on the exterior of the house. Any thoughts as to how difficult this will be for an amateur who's never replaced a window or dealt with siding? I obviously want to make sure that whatever I do is water tight, so I'm planning on caulking the hell out of it. I've been looking for online help, but most are designed for pocket windows. See pictures below. I've been looking at a window at Menards. I'm sure it's not all that great, but this is for a garage after all, and I'm looking to keep costs down.

 

[bczygan]

Never use caulk or sealants of any kind as the primary method of sealing against water.

Use mechanical methods first.

Then use caulk as a back up.

Google installation methods. You will have to remove some siding.

Likely that you new window won't match the existing size and you will need to re-frame and cut sheathing and rework the siding. Make the new one bigger since you have no siding to fill in.

If you are heating the garage this is a good chance to get energy efficient windows.
Match the style and placement on the rest of the house.

 

[Slednut]

If you can buy windows that will just fit in the rough opening get them with the brick molding installed.

Cut out the siding and aluminum frame of the window with a skill saw as close to the frame as possible (it will ruin the blade but they’re cheap).

Get some help and hold the new window in the opening, plumb and level it.

Mark the siding next to the brick molding.

Cut just the siding on the mark leaving enough room for new vinyl trim.

Install new vinyl trim.

Install the new window.

 

[alwaysFlOoReD]

Both bczygan and slednut have good points.
I've done renos for quite a few years and here is how I would do mine. It would require no new siding. I would buy a custom vinyl window with a vinyl "renovation" brick mold attached, sized about 1/8" smaller on all four sides so that the window molding butts up against the siding jay. Some measurements recorded from the ends of the wall, as well as from the soffit above and foundation below the window is necessary to locate the new window. A "zip" tool will make removing the siding easier. Remove the siding starting with the row above the window. Number them as you go, be careful as you probably won't be able to match that siding if you break a piece. Next remove the siding jay that surrounds the window. Prep the wall opening with new black paper where needed and I would suggest some asphalt "sticky" tape around the perimeter. Using the previously recorded measurements, attach the window. If the brick mold doesn't have a removeable top piece to hide screw heads, drill holes sized for plastic caps sourced from the window supplier or a big box store. Use panhead screws to attach the window threw the holes drilled into the SIDES and TOP of the inside of the windows, never into the bottom. Most times there are removable strips that hold the glass in place and you can use screws there so no holes are apparent. Make sure to shim the window where the screws are going to be placed. Use low expanding foam to seal around the window [hi-tech] or batt insulation cut into strips and pushed in between the framing and window [low tech]. Use aluminum drip cap above the window if the soffit line is not double the length out from the wall as it is high above the window.
Remember that water wants to run downhill so make sure that the paper overlaps to prevent water ingress. Use caulking where the jay hits the brick mold/wall. Replace siding. If necessary caulk gap between siding jay and new window. Crack a beer, you deserve it. Stand back and admire job.
Good luck,

Richard

 

[FarmerPete]

Hmm. I'll have to do some research into removing vinyl siding. I have a couple spare pieces that the previous owner left in the garage rafters, but I certainly don't want to break anything.