DIY Replacement Windows
Installing a window
yourself will only work when the replacement window is the same size
and shape as the old one and when the existing window opening is square.
To determine whether your window opening is square, measure it
diagonally one way (from the upper left corner to the lower right
corner) and then the other (from the upper right corner to the lower
left corner). If the opening is square, the two measurements will be the
same, give or take 1/8 inch. The slightest deviation from square can
prevent the sash from closing and the weather stripping from sealing
properly. If that happens, you'll be stuck with drafts, condensation,
and high utility bills.
On November 19, 2010
