How to install new window in hardie

[LeanMachine]

We recently had a garage built. I am doing all the inside work. It includes a bath and laundry room. The wife decided she wants a window in the laundry room. What is the proper procedure to install a new window in preexisting hardie board and batten siding?

I'm guessing you have to cut a big enough hole in the siding to install and flash window? Then cut siding pieces as spacers and install trim on top?

[Cookiemonster1]

You can cut it so you can trim it flush and caulk and paint. Use good flashing tape and build a seel for it. Tape sides and then top leaving the bottom un-taped. If the top is not protected by a good overhang you will need to cut the housewrap back and then cover the tape with the housewrap and tape the cut areas.

[gumbl3]

You'll need to frame the opening if the wall was originally scheduled for one. You can't just cut a hole in the outside and slap a window in. Easy if it's still rough framing. Still easy if finished and you know a few tricks, you'll just have to do some sheetrock repair

[LeanMachine]

You'll need to frame the opening if the wall was originally scheduled for one. You can't just cut a hole in the outside and slap a window in. Easy if it's still rough framing. Still easy if finished and you know a few tricks, you'll just have to do some sheetrock repair

Yea I guess I left that part out. However that's in the I know how to do that category. I have also installed windows before siding was present, in the past. I haven't installed drywall in there yet, so still open framing.

I guess I'm most concerned about the tyvek being cut when I cut out the siding. Not a significant issue I guess as long as the window is flashed appropriately? Do I need to try to put some kind of flashing under the edge of tyvek on top and sides if I can?

[gumbl3]

If it were me I'd tape the bottom of the rough framing and up 6 inches or so. On the bottom the tape overlaps the tyvek so any condensation that gets to the bottom of the window hopefully won't get to bare wood. Slide the new window in behind the tyvkek on top and sides and tape those 3 sides. You have to cut the tyvek an inch or so horizontal at the bottom.

[Notaguide]

I'm assuming it a 8" lap or similar? Will the windows be wrapped with 1x or will you be butting into window flange? How much trouble to tear off the area of siding?

If wrapping with 1x4, figure margins and do the best you can cutting the opening. You should have a little flexibility to run a window tap under remaining siding. It's brittle though so consider it a risk. Z-bar at the top will help if it can be slid under the top piece of siding. Remodeling is always the process of building in reverse.

[LeanMachine]

It's board and batten hardie. Window is in now. Here is how I did it. Framed out the window inside as needed. Drilled holes in the corners from inside out. Drew lines on siding connecting holes. Cut siding with a diamond blade on grinder. Then cut out osb with oscillating saw. Marked a 3 inch margin around the opening. Inserted wood shims between siding and tyvek to give me some buffer. Cut out that 3 inches around opening with diamond wheel. Flashed the sill. Cut top corners of tyvek at 45s. Inserted top Window flange under flap and secured window. Flashed sides. Flashed top. It was pretty easy. Took the longest to figure out the best place to place it to minimize moving utilities in wall. My biggest concern was cutting the tyvek on accident but the shims made a great solution. The trim is 3.5" so should cover the area Cut out by a 1/2". I plan to use some scrap siding as spacers underthe trim.

[LeanMachine]

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[bowhntrmatt]

nice. I was thinking something similar to what you did, except that I figured just cut the siding to size plus 3.5 all the way around for trim, and trim/flash the hole so it looks like it was always like that, then just install a retrofit window without the nailing fin. Your way sounds even better.

[Notaguide]

Sounds like you did all you could do plus some. Being able to install top flange under the existing Tyvek like you did is 95% of the battle. You'd be surprised how most framers do this incorrectly. Good job!

[Big_gun]

make sure you put in a header above the window if wider than the studs OR cut one out. there are tons of videos on this topic.