Window Install

[MJBaldwin]

Alright folks back again for your wonderful advice! I am working on fixing up my kitchen a little here and there and the window is in desperate need of replacement. I am doing a slider just wondering on Rough In dimensions. Ripped off my old trim and looks like a 3/4" of plywood the plaster. Would you add another 2x4 into that opening although a little smaller window might be nice for the nailing flange?

[Surface Tension]

 You have the option of nailing flange or brick mold.  Since this is replacing a window with siding and J channel your choice would be brick mold and from your photo that is what you have now, brick mold.

That is if you don't want mess with the siding and J.

 

 

 Your RO is what it is and again since your home is sided and J channeled,  changing window size will require you to unlock the siding,  remove the J.   Your construction looks old and was common to have large ROs.  Brick mold was nailed to 3/4 ship lap and rarely into a stud, jack studs were rarely used used then and headers were small and toenailed with 30 penny.   If you want to keep the window size the same but fill the oversized RO with a 2x4, sure you can do that.

 Next choice and one I'd recommend is going with  window insert.  You'll leave the exterior trim alone and remove the interior trim and sash. You have full access to the RO to add insulation if necessary. 

 

I do this in my sleep but you might want to wait for a retired guy to spend a day researching it to give you another opinion.

[delcecchi]

Nah, not me.  But if it were my window I would rather have a guy that was awake doing the job.