Measuring · General
The general outside-mount measuring guide
Outside mount is the answer when the reveal is shallow, out of square, or when you want the most light control. The rule is simple: measure the area you want covered, with overlap.
Rather not measure? The in-home measure is free, and then the fit is our problem, not yours.
Step by step
- 1
Mark the area you want covered, adding at least 2 inches of overlap on the left and right for good light blocking.
- 2
Measure that full width, not the window opening.
- 3
Measure the height from the top of the headrail to the bottom finish point, adding overlap at the top where you can.
- 4
Use the longest height and widest width you measured so the covering never comes up short.
- 5
Check that the mounting surface, frame or wall, is flat and sound enough to take screws.
- 6
Enter measurements in inches and eighths, exactly as taken.
Common mistakes
- Outside mount hides an out-of-square opening.
- More overlap means less light leak at the edges.
- Blackout side channels on roller and zebra products give a near-total darkening outside mount.
- Use a valance or cassette to hide the headrail for a finished look.