For outside mount: Measure patio door opening from left to right. Include any window trim or moulding. Round to the nearest 1/8 inch.
Add 4 inches to this measurement. This will allow vanes to cover window trim and eliminate any light gaps that may occur at the sides. If space does not allow for a 4-inch overlap, reduce this number by half. Write down the measurement. This is your patio-door width.
Measure patio-door opening from top to bottom. Include any window trim or moulding. Round to the nearest 1/8 inch.
Add 3 inches to this measurement. This will allow for space needed above the patio door for mounting brackets. If vertical blinds are to reach to the floor, deduct 1/2 inch for clearance. This will ensure blinds operate correctly and do not drag at the bottom. Write down the measurement. This is your patio-door height.
For inside mount: Window openings are sometimes uneven. To find the most accurate measurement, measure left to right inside the patio-door frame at the top, middle and bottom of the opening. Select the smallest measurement. This is your patio door width.
Measure top to bottom inside the patio door frame at the right side, in the middle and at the left side of the opening. Select the smallest measurement. Deduct 1/2 inch from this number for clearance. This is your patio door height.
Things You Will Need
- Steel tape measure
- Pen or pencil
- For best results, select an outside mount when hanging patio-door vertical blinds. Sliding-door patio frames must have an inside depth of at least 2 1/2 inches to accommodate an inside mount. To find out if your verticals can be mounted inside a patio door, measure the depth of the inside frame. Patio hardware such as door handles should not interfere with the operation of verticals. Use a steel tape measure to ensure measurements are accurate. Always double-check your measurements.