Which one is the correct order size with existing wood frame?
A. R/O - 1/2 inch
B. R/O - 1/4 inch
Certainteed web site indicates the deduction is 1/2 inch, but some contractors are saying 1/4 inch.
Window Order Size to Rough Opening (R/O)
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- Posts: 11
- Joined: Sat Aug 26, 2006 7:38 pm
Here's the key: how out-of-square is your EXISTING frame or RO? ALWAYS Deduct the amount out-of-square PLUS and extra 1/8" both ways. To find out-of-square take the greatest of these differences: The diagonal from top left to bottom right, minus the diagonal from top right to bottom left. Then measure the height left, center, and right and subtract the shortest from the tallest. Then measure the width top, middle, and bottom and subtract the shortest from the longest. The GREATEST of these 3 sets of numbers should have 1/8" added to it to determine the difference between your existing SO and the new make size. If this isn't clear, you shouldn't be doing this yourself--get someone who knows what they're doing or you'll just be spending money and not improving your energy efficency or your home's value. Good Luck!