How to Measure and Install Outdoor / Exterior Shades
The fear that stops most people from ordering custom outdoor shades online is simple: what if I measure wrong and the expensive custom shade does not fit? It is a reasonable fear and a solvable one. Custom shades are built to the numbers you submit, which means the risk lives in five careful minutes with a steel tape.
To measure for an outdoor shade, choose a mount type, then measure the opening to the nearest one-eighth of an inch in three places and use the right figure. The numbered steps below cover each mount type, plus the deductions and checks that prevent a refit.
Before you measure: tools and mount types
You need a steel tape measure, not cloth, a pencil, and paper. Measure to the nearest one-eighth of an inch and write down every number. Then decide your mount type: inside mount fits the shade within a solid, square opening for a clean look; outside mount fixes the shade to the surface around the opening for maximum coverage and is the safer choice when an opening is not square; ceiling or soffit mount hangs the shade from above; and between-posts mount spans an opening between two posts. When in doubt, choose outside mount, because it is the most forgiving of uneven openings.
One thing to know before you order: your width is measured bracket-to-bracket, and the fabric runs slightly narrower than the brackets to clear the housing and rails. That means an inside mount will show a small light gap at the sides. If you cannot tolerate a gap, choose an outside mount, which covers the whole opening.
How to measure for exterior roller and solar shades
Inside mount
- Measure the width inside the opening at the top, middle, and bottom. Use the smallest of the three figures.
- Measure the height at the left, center, and right. Use the smallest of the three.
- Check for square: measure corner to corner both ways. If the two diagonals differ by more than one-quarter inch, the opening is out of square, so use shims or switch to an outside mount.
- Confirm a solid, level surface to hold the cassette and rails, and check there is enough flat, unobstructed depth, clear of any handles, cranks, or fixtures.
Outside mount
- Measure the full area you want covered, overall width and overall height, to the nearest one-eighth of an inch.
- Add coverage on each side: about 3 inches per side for a roller shade, or about 4 inches per side for a side-track shade so the rails clear the opening.
- Confirm a strong mounting surface such as a beam, header, posts, or wall.
How to measure for side-track (zip-track) shades
Side-track shades need the rails to land on solid, parallel surfaces, so measuring is about the mounting structure as much as the opening. Confirm both sides have solid, vertical surfaces (posts, a frame, or a wall) where the rails will run, and that they are plumb and parallel. Measure the width between the intended rail positions and the full drop from the housing location to the sill or floor. Because the fabric edge rides inside the rails, the rails must be straight and parallel for the zipper to feed smoothly, so check this before you commit to numbers.
How to measure openings, posts, and pergola spans
For a span between posts, measure the clear distance between the inner faces of the posts at the top and bottom and note any taper. For a pergola, measure the actual span you want to screen, beam to beam or post to post, and the drop from the beam to the floor. Old structures are rarely perfectly square, so measuring in more than one place catches a lean before it becomes a fit problem. When a span is large or uneven, outside or between-posts mounting absorbs the irregularity better than a tight inside mount.
Common measuring mistakes and how to avoid them
- Measuring in only one place. Always measure width and height in three spots.
- Rounding instead of measuring to the nearest one-eighth of an inch.
- Assuming an opening is square. Check the diagonals; that is why an inside mount uses the smallest figure.
- Mounting to a weak surface. Install into solid structure such as wood framing, beams, posts, concrete, or brick, and locate the structural member behind siding or stucco with a deep-scan stud finder before drilling.
Installation overview and what comes with a custom order
Most customers install these shades themselves by following the included instructions, and two people make it faster and safer because of the housing and side rails. Every custom order arrives with the pre-assembled top housing (the cassette with the motor and internal parts), the left and right side rails with zip-track, mounting screws with anchors, and United States standard plugs, with a digital manual sent by email. Motorized shades are factory pre-wired and run from a standard 120-volt outlet, so plan for an outlet near the install point or have an electrician add one.
When to request help or a professional measure
DIY is the norm, but call in help in three cases: a very large or high span where handling is unsafe for two people, an opening you cannot confirm is solid and square, or a structure you are not certain can carry the load. Value Blinds partners with a professional measure-and-install network that covers most of the continental United States, and you can check local availability by ZIP code on the professional measure and install page. A professional measure is cheap insurance on a large or awkward opening.
Frequently asked questions
How do I measure for outdoor shades? Use a steel tape and measure to the nearest one-eighth of an inch. For inside mount, measure width at top, middle, and bottom and height at left, center, and right, then use the smallest figure for each, and check the diagonals for square. For outside mount, measure the full area to be covered and add about 3 inches per side.
What is the difference between inside and outside mount? Inside mount fits the shade within a solid, square opening for a clean look but leaves a small light gap. Outside mount fixes the shade to the surface around the opening for maximum coverage and is the safer choice for uneven openings.
Can I install outdoor shades myself? Yes. Most customers install these themselves using the included instructions, with two people recommended. For large, high, or uncertain openings, a professional install is available across most of the continental United States.
How do you measure for side-track shades? Confirm both sides have solid, plumb, parallel surfaces for the rails, then measure the width between the rail positions and the full drop. Straight, parallel rails are essential for the zipper to feed smoothly.
What happens next
- Choose your mount type, then measure with a steel tape to the nearest one-eighth of an inch, in three places.
- Request free samples while you finalize numbers. Samples ship by FedEx, UPS, or USPS.
- Submit your measurements and order custom-measured exterior shades, or book a professional measure for a large or awkward opening.
- Your shade is built to your numbers in about 4 to 5 weeks and ships by truck freight, delivered curbside.
