A gapping window treatment can be caused by poorly-sized curtains, broken rods and breezes. When selecting your window treatments, it is important to recognize how the features of a particular room will affect the performance of the curtains. For example, if the window frame slanted the length of curtains, the drop must compensate. A room with a strong cross-breeze requires heavy fabric or weighted curtains. Considering these features before installation can save time and money correcting a problem with gaps.
Things You'll Need
Metal Measuring Tape
Raise or lower the curtain rod to cover gaps at the top or bottom of the window frame.
Install wider curtains to fill gaps at either side of the frame. Measure the length of your existing curtains, pole or curtain track from one end to the other. Multiply the measurement by 1.25; this will provide you with a size that is 25 percent larger than the original curtain. Consider expanding the width of the curtain pole as well; this will allow you to pull the curtain over further.
Increase the width of the existing curtains by sewing bias tape to the sides of the curtain. Measure the width of the gap. Divide by the number of vertical edges; if you do not wish to sew bias tape to every vertical edge -- for example, if you only want the tape in the middle of the window -- divide by the number of vertical edges you will be using. Add 1/2-inch seam allowance to determine the width of the bias tape -- e.g., a 2-inch gap on a single panel curtain where both vertical edges will be taped, requires a 1 1/2-inch wide bias tape. Cut a piece of bias tape 1 inch longer than the full vertical length of the curtain, sew to the side of each panel and miter the corners for a finished look.
Increase the length of the existing curtains by sewing bias tape to the bottom of the curtain. Measure the width of the gap and add 1/2-inch seam allowance to determine the bias tape needed-- e.g., a 1-inch gap requires a 1 1/2-inch wide bias tape. Cut a piece of bias tape 1 inch wider than the bottom of the curtain. Consider adding bias tape to the sides of the curtain for a uniform appearance.
Sew or clip five to 10 curtain weights to the bottom of the curtain at even intervals to weight the curtain down and prevent gaps from breezes.
Correct a gap due to a central support bracket by overlapping the curtain panels on the rod. Select curtains that have rings or eyes instead of a tubular rod casing at the top. Hang the right-most ring of the left curtain on the rod with the interior-side of the curtain facing toward you. Slide the left-most ring of the right curtain panel onto the left end of the curtain rod with the interior-side facing you; the center-most rings of each curtain panel will now be crossed. Slide both panels to the right-end of the rod and continue affixing the rings of the right panel as you normally would. Repeat on the left side. Attach the curtain so that the center bracket falls between the overlapping rings.