New windows in Stucco

Old 08-08-11, 04:12 PM
griznhoney's Avatar
Thread Starter
Join Date: Dec 2005
Location: USA
Posts: 22
Upvotes: 0
Received 0 Upvotes on 0 Posts
New windows in Stucco

My home is a 1940's home with stucco. I have plans to upgrade the original wood frame windows with frames that are beginning to rot and then blow in exterior wall insulation. My question is on the window upgrade. I am thinking that I would want to make a first cut close to the original frame and work my way out to find the actual wall frame (sorry for the terms). Then I should be able to cut the nails/screws and pop the old window out? Then replace them, and repair the stucco...I know sounds WAY easier than it will be right? Thanks for any input!

Old 08-08-11, 07:19 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 14,085
Received 781 Upvotes on 661 Posts
Not a window pro but I have helped a pro on some window jobs.

IMO - you should remove the inside window casing to determine what your rough opening is. When it comes time to swap the windows you should start in the middle and work your way out. Remove the windows first, then remove the stops, then jambs and the sill. With luck you will not damage the stucco at all and the new window will slip in. Likely you will have to cut new casing on the outside and caulk.
Old 08-08-11, 07:36 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Posts: 26,664
Received 1,811 Upvotes on 1,628 Posts
Tolyn is definately on the right track. You shouldn't begin by cutting the stucco on the exterior. That's the LAST thing you would do, and only if needed, because it will save you from opening a large can of worms. (if you want to open that can, see the last paragraph).

By removing the interior trim, like he mentioned, you will be able to determine the maximum size of the rough opening. Keep in mind that it's often advantageous to add a 2x4 (or more) onto the existing framing to "pad in" the existing rough opening, so as to be ready for a new construction window (with nailing fin).

So I'd also recommend that once you remove your interior trim and get an idea of how big your opening will be, that you go on the outside and do some measuring, and try to determine the size of your STUCCO opening. If you wanted to try to avoid cutting any stucco, you'd pad out the rough opening on the inside so that it is about 2" smaller than your stucco opening. Then if you order the window 3" smaller than your stucco opening, you should have a 1/2" gap all the way around your new window to level, shim, square and insulate.

You would then install trim over the nailing fin, and generously seal the perimeter with a polyurethane sealant.

Of course, the best installation would indeed include demo to the stucco (about 6" around the entire window perimeter) in order to incorporate the new window into the stucco's weather resistive barrier (WRB) in a "proper" way... but that is usually WAY beyond the scope of a DIY job. When doing this, you also do NOT cut the stucco, but you carefully break it with a hammer so as not to damage the wire or WRB. Leaving a rough irregular perimeter also helps bond the new stucco repair to the new, since a straight line has a tendency to not only crack, but show up as an obvious repair. Matching the texture is a difficult job that only the most experienced stucco-er (stucco-ist? LOL) can master. I've replaced windows for 20 yrs and stay as far away from stucco houses as I can. Fortunately they aren't too common in my area.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: