Measuring rough opening w/o x-ray!

[Toadhall]

Hi,

I have three double hungs that I'm replacing DIY with "new construction" so of course I need the rough opening. Everything I ever read or see about window install leaves out the crucial measuring step (liability? and shows some happy guy in front of the old window, and the new window delivered and ready to go.

The outside is stucco and the inside is lathe and plaster. I have removed the interior case and apron, and discovered the plaster is run flush all the way around, so I can't inspect for the studs that way. I don't want to order too small, but I also don't want major wall surgery.

So..

How can I get the rough opening without tearing out the old window, and living with a tarp for four weeks while I wait for the new one?

Thanks,
Toadhall

[Window4U (IL)]

Drill a hole in each side, sill, and header being careful to not drill any further than just through the wood of the window.
Then stick a long nail in the holes until they hit the stud.
Grab the nail tightly where it meets the jamb and pull it out.
Measure how much nail you have protruding out from your tightly clasped fingers.
Add those dimensions, first width, then height to your interior wood to wood dimensions. Make sure you measure the interior sill to header dimension exactly where the hole drilled in the sill is. You don't want a sloped sill to throw you off.
This will give you your rough opening size. The actual window unit size on an existing home will depend on your individual situation.

Note: Do a little research with the search function on this site before doing a full frame replacement on a stucco house. You need to know proper installation methodology or you may end up with a leakage disaster which may damage your stucco and walls.

[Toadhall]

Thanks for your reply!

Re: Drilling to measure
I had considered this, but wasn't sure about how to get it right. For example, on the sides, how do I miss the weight pocket and know when I'm past that? The head and sill seem more straightforward, unless I hit shims straight away or it's sitting on the opening. Any additional advice?

Re: Stucco
I did a search and came across some leaking stucco threads (pictures were missing), but perhaps you could point me to specific discussions you were thinking of, or better yet recommend a video or how to for this kind of install.

My house is mix of vertical T&G wood siding and old stucco (1930's). The windows in the wood area have trim, the windows in stucco areas don't except for a little stop at the edges before the stucco starts. I have seen DIY stucco patch jobs on old houses and the stucco texture is different so the patches look horrible. So may plan was to add wood trim to the stucco windows and in doing a) unify the look of my windows, and b) hide the installation damage.

Here were the steps I was planning:
1. Lay the new trim over the stucco and mark the edge.
2. With a circular saw, shallow cut (only the stucco) around the window following the trim edge.
3. Tape the rough opening with that wide adhesive flashing tape (ship-lap style)
4. Install the new window, back caulking the nailing fin on top and sides (window has built-in drip cap).
5. Flashing tape on top of the fin (again ship-lap style)
6. Add the trim
7. Caulk the trim/stucco and trim/window edges

Does that sound ok, or shall I build an ark while I'm at it?

[Toadhall]

Re: Drilling to measure
With your help, I now have x-ray vision! I just got done drilling and it was easier than I thought. I was worried that I wouldn't be able to tell how deep I was, but it was a snap. Thank you (and all the other faithful regulars) for answering us weekend jockeys, what a help. On the side jambs, I just inserted a long screwdriver around the pulley to get the depth of the weight pocket. Then I added .75" for the width of the frame. Does that seem about right?

Code: Select all

 .75" +      3"      +      36"     +      3"      +  .75"
frame + weightpocket + sash opening + weightpocket + frame

Re: Stucco
Any comments on my plan (above)?