- 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.