I’m currently on an add a level addition that requires some masonry alterations. I can set block neatly and evenly enough to get the job done. Also, I doesn’t hurt that any boo boos I make will be covered with stucco.
My question is how to make a proper rough opening. The window supplier said to add 1 inch to the nominal height of the window. O.K. easy enough, a 42″ window requires a 43″ R.O.
Is the RO measured from the bottom of the lintel to the bottom of the lip on the sill or the top of the lip?
Any feedback regarding openings or general masonry technique would be helpful.
Cheers
Replies
Tapcon,
What ever the Rough Opening is I tell the mason to add 4" for the width and height because we always build a 2x box around the masonry opening first and nail that into the block and then nail the window flanges into the 2x box unless it's a basement window then the masons install them and plaster them right into the foundation.
I say 4" because the 2x box always equals about 3-1/8" to 3-1/4" so that gives you some play if the masonry opening is not cut straight because you don't want it too tight, it's always easier to have the opening a little bigger than smaller.
Your window supplier should give you the rough opening or give you a book on the type of window you have but anyway in your case if the rough opening height of your window is 43" then you should make the opening in the block 47" and if for example your rough opening for the width is 40" then you make the opening in the block 44".
Joe Carola
Edited 12/18/2003 6:32:50 PM ET by Framer
I did the 2x deal and went four inches also but I got one window that tight so maybe 4 1/4 would be better. measure the window add a 2x on each side and add 1/2 to 3/4 inch for shims. I think one of my treated 2x was little thicker than 1 1/2 inches
The best employee you can have but you wouldn't want him as a neighbor " He the shifty type"
I did the 2x deal and went four inches also but I got one window that tight so maybe 4 1/4 would be better.
Sounds good to me. I've seen some masons with their openings and it looks like they cut with their eyes closed or they were drunk, so sometimes you have to go more than that, that's why I always check the openings first to make that decision.
Joe Carola
Joe ..edit your last line 40" does not need 47" or am i missing somthin?
Thanks Sphere. Your not missing something I just made a mistake.
Joe Carola
I think you should get the windows on site so that you can know what the exact outside dimentions are.