Always order windows by name specifying blindstop or overlap.
Always give exact opening width and height.
On windows for blindstop installation, we will cut back under opening size 1/8" on width and height.
Example: Actual size of storm window to fit a 36" x 55" opening for blindstop installation will be 35 7/8" x 54 7/8", including sill expander.
On windows for overlap installation, we will add 1 ¼" to opening width and ¾" to opening height.
Example: Actual size of a storm window to fit a 36" x 55" opening for overlap installation with be 37 ¼" x 55 ¾", including sill expander.
NOTE: Columbia does not recommend the use of storm windows for porch enclosures.
