Sizing and engineering · Rolling Shutter Guide
How wide and tall can a rolling shutter be?
A single Roll-A-Shield rolling shutter can be up to 224 in (18 ft 8 in) wide or 216 in (18 ft) tall, but not both. Each slat also has an area limit: 112 sq ft for 38 mm insulated, 156.5 sq ft for 55 mm insulated, 200 sq ft for 63 mm single-wall. Wider openings take two or more shutters.
Key facts
- Maximum clear-opening width per slat: 159 in (38 mm insulated), 224 in (55 mm insulated), 222 in (63 mm single-wall, solid or perforated). Roll-A-Shield data
- Maximum clear-opening height is 216 in (18 ft) for every slat. Roll-A-Shield data
- Maximum area per slat: 112 sq ft (38 mm), 156.5 sq ft (55 mm), 200 sq ft (63 mm). Area usually limits a shutter before width or height does. Roll-A-Shield data
- Width and height limits are measured at the clear opening; the guide rails and box are added outside it. Roll-A-Shield data
- Every Roll-A-Shield shutter is built as one unit with its own pair of guide rails and its own box; two shutters never share a box or a motor. Roll-A-Shield data
Applies to: Roll-A-Shield 38 mm and 55 mm insulated and 63 mm single-wall (solid and perforated) rolling shutters, any operator. Other makers set their own limits.
Three limits apply to every rolling shutter at once: a maximum width, a maximum height and a maximum area. In practice the area limit is the one people run into, because a shutter that is as wide as the slat allows cannot also be as tall as the slat allows. The figures below are Roll-A-Shield's, for its three slat profiles.
What are the size limits for each slat?
The width and height limits apply to the clear opening, and the area limit is the clear-opening width times the clear-opening height.
| Slat | Max width | Max height | Max area | Tallest at max width | Widest at max height |
|---|---|---|---|---|---|
| 38 mm insulated | 159 in (13 ft 3 in) | 216 in | 112 sq ft | about 101 in | about 74 in |
| 55 mm insulated | 224 in (18 ft 8 in) | 216 in | 156.5 sq ft | about 100 in | about 104 in |
| 63 mm single-wall | 222 in (18 ft 6 in) | 216 in | 200 sq ft | about 129 in | about 133 in |
| 63 mm perforated | 222 in (18 ft 6 in) | 216 in | 200 sq ft | about 129 in | about 133 in |
The last two columns are worked out from the area limit: divide the area (in square inches) by the width or the height. For example, a 38 mm shutter at its full 159 in width tops out at about 101 in tall, because 112 sq ft is 16,128 sq in and 16,128 / 159 is about 101.
These are the largest sizes Roll-A-Shield will build; shutters near the top of the range are checked by the factory before they are made.
Why can't a shutter be both maximum width and maximum height?
Because each slat profile has an area limit as well as a width and a height limit, and all three checks apply at once on every order; the area check is usually the first to bite. A wide, short opening such as a counter or a carport can use the full width; a tall, narrow one such as a two-story window can use the full height; a big square opening is limited by area.
Area is also why the slat choice narrows as a shutter grows: the 38 mm insulated slat drops out first, and the largest shutters are 55 mm insulated or 63 mm single-wall. The full rule is in Why your slat choices narrow as the shutter gets bigger.
Does a big shutter have to be motorized?
Beyond the manual limits, yes. Strap and crank shutters are limited to a curtain of about 50 lb, which is a small window or door. Spring-loaded shutters go further, to 192 in wide, 120 in of curtain height and 144 sq ft. Anything larger is motorized, and the 55 mm insulated slat is built motorized only. At the other end, the heaviest curtains in this table are well over 200 lb: 200 sq ft of 63 mm single-wall slat is about 228 lb at the sizing weight of 1.14 lb per sq ft. The motor is chosen by that curtain weight, not by the width. See How big can a manual shutter be before it needs a motor? and How much does a rolling shutter weigh?.
How much bigger is the whole shutter than the opening?
The limits above are for the opening; the shutter itself is larger. Overall width is the clear opening plus one guide rail on each side, and overall height is the clear opening plus the box plus about 2 in, because the bottom slat stays in the rails below the box when the shutter is up. Taller shutters need bigger boxes, from 6.5 in up to 12 in nominal. So an 18 ft tall opening needs roughly another foot or more of wall above it for the box. The box sizes are in What size box do I need? and the dimension terms in Clear opening, overall size and curtain width.
What if my opening is wider than the limit?
It is covered with two or more shutters side by side. Each one is built as a separate unit with its own pair of guide rails, its own box and, if motorized, its own motor. The split does not have to be down the middle: where it falls is agreed between you and the sales rep, usually at a post, mullion or other solid mounting point, and for looks. Covering a long opening is explained in Covering a 16-20 ft opening.
Tip: Very wide shutters bring one more practical limit: the axle carrying the curtain bends slightly over a long span. Roll-A-Shield's sizing steps the box up a size when the calculated sag would reach half an inch; see Why wide shutters sag.
What next
Send the clear-opening width and height of each opening on a quote request, or call (480) 921-0200, and the factory will confirm the slat, box and operator that fit. For budget figures, see How much do rolling shutters cost?.
Frequently asked questions
What is the widest rolling shutter you can make?
On the 55 mm insulated slat, 224 in (18 ft 8 in) of clear opening; on the 63 mm single-wall slat, 222 in. At those widths the area limit holds the height to about 100 in and 129 in respectively.
Can one rolling shutter cover a twenty-foot opening?
Not as one Roll-A-Shield shutter. A 20 ft (240 in) opening is wider than any slat's limit, so it is covered with two shutters side by side, each with its own guide rails and box.
Is the size limit measured on the opening or the whole shutter?
On the clear opening: the width and height of the hole being covered. The guide rails add to the width and the box adds to the height on top of that.
How tall can a shutter be?
Up to 216 in (18 ft) of clear opening on any slat, provided the width keeps the shutter inside its area limit.
Parts and next step
Need a part or a hand?
Replacement motors, remotes, straps, slats and hardware ship from our Tempe, Arizona factory. Phoenix-area owners can book a service visit; everywhere else, our technicians help by phone. Call (480) 921-0200; the factory answers technical questions for any rolling shutter, not only ours.