Key facts

• Surface mount: send the inside (clear-opening) width and height and the factory adds the rails and box. Recessed mount: send the overall size the whole shutter must fit inside. Roll-A-Shield data
• Overall width is the clear opening plus both guide rails; overall height is the clear opening plus the box plus about 2 in for the bottom slat. A 48 x 48 in opening becomes about 52 x 56-1/2 in overall on a 38 mm shutter. Roll-A-Shield data
• Roll-A-Shield works out the overall size, clear opening and guide-rail lengths in eighths of an inch, each rounded to the nearest 1/8 in, so measure to the nearest 1/8 in. Roll-A-Shield data
• Minimum widths by operator: strap about 10 in overall, spring 31 in overall, motor typically 28 in overall. Roll-A-Shield data
• The largest Roll-A-Shield builds are 159 in wide (38 mm), 224 in (55 mm) and 222 in (63 mm single-wall), up to 216 in tall, but the area limit usually binds first. Roll-A-Shield data

Applies to: Rolling shutters on windows and doors, surface or recessed mount, any make; Roll-A-Shield 38 mm and 55 mm insulated and 63 mm single-wall shutters with strap, crank, spring or motor operation.

A rolling shutter is built to the size you send, and its box and rails add to the opening on every side. This page follows the Roll-A-Shield measure sheet, the form self-installers send to the factory, and explains what the factory does with each number. Installing is covered on Can I install rolling shutters myself?.

What tools do I need?

• A steel tape measure
• A level, to find the high and low points of a sill or head
• A pencil and the Roll-A-Shield measure sheet, one row per opening
• A phone camera; photos of each opening help catch measuring mistakes before the shutter is built
• A step ladder for the head of the opening

What do I measure?

Width, height and five details about the opening. Number each window or door and record:

1. Width at the top, middle and bottom. Openings are rarely square, so write down the smallest and the largest reading, to the nearest 1/8 in.
2. Height at the left, center and right. Again record the smallest and largest. If one side is taller, say which; the box height follows the taller side and each guide rail is made to its own true length.
3. Mount type. Surface (box and rails on the wall face) or recessed (box and rails inside the opening, rails fixed into the side walls). See inside vs outside mount if you are not sure which you have room for.
4. Obstructions. Anything that sticks out past the wall plane: door handles, hinges, casement cranks, trim.
5. The sill. Is there a flat, solid surface for the closed curtain to rest on?
6. Operation. Spring, pull strap, crank, switch motor, remote motor, solar or battery.
7. Control side. Left or right, as you see it looking at the front of the shutter box.

Do I give you the opening size or the overall size?

It depends on the mount, and you give one or the other, never a mix. The measure sheet asks you to pick inside or overall for each opening.

• Surface mount: send the inside width and height of the opening (the clear opening). The factory adds the guide rails outside it and the box above it.
• Recessed mount: send the overall width and height of the space. The factory builds the whole shutter, box and rails included, to fit within it.

On a surface mount, Roll-A-Shield turns your clear opening into an overall size like this: overall width is the clear opening plus the width of both guide rails, and overall height is the clear opening plus the box plus about 2 in for the bottom slat. At install, installers usually leave about 1/4 to 1/2 in of wall showing between the window frame and the inner edge of each rail (the reveal), so the rail lands fully on the wall rather than half on the frame, with some forgiveness on uneven brick or stucco.

A worked example: a 48 × 48 in clear opening comes out about 52 × 56-1/2 in overall on a 38 mm shutter (mini rails, 6.5 in box), and about 54-3/4 × 58 in on a 55 mm shutter (standard rails, 8 in box). That surface space, not just the opening, has to be free on the wall.

The most common measuring discrepancy is not a wrong reading but a clear-opening number entered as an overall size, or the reverse; label every number.

How much room does the box need?

The box size depends on the slat and the curtain height, which is the clear opening height plus about 2 in. Roll-A-Shield boxes come in nominal sizes of 6.5, 7, 8, 9, 10, 12 in, and the sizing chart picks the smallest box that holds the curtain.

These are sizing figures. The 55 mm column is for the 70 mm axle a motorized 55 mm shutter normally uses; on a 60 mm axle each box holds a somewhat taller curtain. A wide span where axle sag matters steps the box up one size, and box sizes are nominal: the 8 in box, for example, is 8.150 in tall. On a recessed mount, measure the height and depth of the recess and confirm the box size before you order. On 63 mm single-wall shutters the chart also depends on the end-retention spacing, so ask for the exact size.

What if the opening is out of square or the sill slopes?

Send every reading; the measure sheet asks for the minimum and maximum of each dimension for this reason. On a tight recessed or trapped opening, send the smallest reading and say the opening is trapped. The shutter needs a little fitting room so it is not a fight to install; agree with Roll-A-Shield who allows for it before you order, so it is neither missed nor taken twice.

If the two side heights differ, the rails are made to their true, different lengths and the box is sized for the taller side. A sloped floor or sill is different: no rolling-shutter slat is made to follow a slope, so a noticeable gap at one end needs a custom bottom solution. Photograph it and call before you order.

What about door handles, hinges and sills?

• Furring. If a handle, hinge or crank sticks out past the wall, the shutter stands off the wall on furring or the curtain hits it and stops. Roll-A-Shield furring is 1 × 2 in aluminum tube, color-matched: 1 in of clearance laid flat, 2 in on edge. Measure how far the obstruction projects and note which sides need furring. Whatever you add on one side, add on the other so both rails sit on the same plane.
• U-channel. If the sill gives the closed curtain no flat surface to rest on, or you want a better light seal at the bottom, order a U-channel. Long, wide spans need support along the bottom or the curtain sags. A U-channel cannot go where people walk, because it is a trip hazard, and spring shutters use an L-angle instead.
• Storm bar. A patio or carport enclosure with no solid backstop behind the curtain may need a removable storm bar; mention it. Single-wall shutters do not take one because their slats are end-retained.

Which side should the motor or strap be on?

Choose the side you want the strap, crank or motor wire to exit, as seen looking at the front of the box, and put it on the same side as your power for a motor. The measure sheet asks for the power source to be within 3 ft of the shutter on wired motors. Two shutters side by side can have opposite control sides so both motors reach one power point. Choose the operator now: Roll-A-Shield does not build shutters to be motorized later; converting one is a service job.

How small or large can a rolling shutter be?

The operator sets the minimum width and the slat sets the maximum size. Strap and crank operators are limited by curtain weight, about 50 lb, and motors are sized to the weight of the curtain, not its square footage.

These are the largest sizes Roll-A-Shield builds; the biggest are reviewed by the factory before they are confirmed. The area limit usually binds before width and height do: a 38 mm shutter at the full 159 in width caps at about 101 in tall. Openings beyond these limits are split into two or more shutters, ideally meeting at a mullion.

What are the most common measuring mistakes?

1. Mixing clear-opening and overall numbers in one order, or not saying which is which.
2. Measuring once. A single reading misses an out-of-square opening; measure each dimension at several points.
3. Missing an obstruction. Without furring, a projecting handle stops the curtain before it closes.
4. No support at the bottom. A curtain with nothing flat to land on, or a long unsupported span, sags and struggles to lift.
5. A recess too shallow for the box. Confirm the box size before ordering a recessed shutter.
6. Picking an operator the size does not allow, such as a spring unit on a narrow window. Check the tables above first.

Who checks my measurements?

When Roll-A-Shield installs in metro Phoenix, a technician normally takes a final measure on site and the shutter goes to production on those numbers. Outside Phoenix, the shutter is built to the measure sheet you send, so send photos of each opening; they let the factory spot a mount, obstruction or sill problem before anything is cut.

What next

Send your sizes and photos through the quote form or call (480) 921-0200 with the measure sheet in front of you. For what a shutter of your size costs, see How much do rolling shutters cost?, and for the names of the box, rails and slats used on this page, see parts of a rolling shutter.

Watch it done

Roll-A-Shield Measure Guide

The written steps on this page are the reference; the video shows the same job.

Frequently asked questions

Should I measure from the outside or the inside of the window?

Measure where the shutter will mount. On a surface mount, measure the opening itself; on a recessed mount, measure the space between the side walls of the recess and from the head to the sill.

Does the box or the bottom bar count in the clear opening?

No. The clear opening is the opening only. The box sits above it and about 2 in is added for the bottom slat, which is why the overall height is larger than the opening.

Can you quote from rough measurements or photos?

Yes, for a quote: send approximate sizes and photos through the quote form. The shutter itself is built to final sizes: on Roll-A-Shield installs in metro Phoenix a technician normally takes a final measure on site, and elsewhere the shutter is built to the measure sheet you complete.

How precise do my measurements need to be?

To the nearest 1/8 in. Roll-A-Shield works out the overall size, clear opening and guide-rail lengths in eighths of an inch, each rounded to the nearest 1/8 in.

Related questions

• Inside mount or outside mount: which is right for a rolling shutter?
• What are the parts of a rolling shutter?
• Can I install a rolling shutter myself?
• How do I install a strap or crank rolling shutter?
• How much do rolling shutters cost?
• Request a quote
• Somfy vs Gaposa: rolling shutter motors