Sizing and engineering · Rolling Shutter Guide
How do spring-loaded (push-up) rolling shutters work, and how big can they be?
A spring-loaded shutter has no motor or strap: a spring in the axle balances the curtain so you lift it open and pull it closed by hand, and a correctly set spring holds it at any height. Roll-A-Shield builds them up to 192 in wide, 120 in tall and 144 sq ft, locked at the bottom bar.
Key facts
- Spring-loaded limits: up to 192 in wide, 120 in tall and 144 sq ft, in a box no bigger than 10 in, and at least 31 in wide overall. Roll-A-Shield data
- Spring-loaded shutters are built with the 38 mm insulated or the 63 mm single-wall slat; the 55 mm insulated slat is motorized only. Roll-A-Shield data
- Spring shutters ship with two tensioning rods, and most ship with no tension in the spring so it can be set on site after installation; only units on a 40 mm axle are pre-tensioned at the factory. Roll-A-Shield data
- Spring shutters get a full-width L-angle at the sill instead of a U-channel; on 63 mm single-wall spring units the L-angle is optional. Roll-A-Shield data
- Spring units are not recommended near the coast; motorized or single-wall shutters are the better choice in salt air. Roll-A-Shield data
Applies to: Spring-loaded (push-up, push-pull, spring-assist) rolling shutters, any make; Roll-A-Shield spring units with 38 mm insulated or 63 mm single-wall slats.
A spring-loaded shutter, also called a push-up, push-pull or spring-assist shutter, is the manual option that reaches openings too big for a strap or crank. There is no motor and no strap through the wall: you lift the bottom bar to open it and pull it down to close it, and a spring does most of the work.
How does a spring-loaded shutter work?
A coiled spring inside the axle is wound up so that it balances the weight of the curtain. When the balance is right the curtain feels light, stays wherever you let go of it, and stays down when closed so it can be locked.
The spring is set at one end of the axle, where a barrel-shaped tensioner turns to add or remove tension and a locking pin holds the setting. At the top of its travel, on single-wall units, a full-width handle on the bottom bar meets a lip on the bottom of the box, which acts as a cushioned stop.
Because nothing is electric, spring shutters suit storefronts and openings without power nearby.
How big can a spring-loaded shutter be?
On Roll-A-Shield shutters a spring unit has its own limits, and the slat's limits apply as well.
| Limit | Spring-loaded |
|---|---|
| Maximum width | 192 in |
| Maximum height | 120 in of curtain, which is the clear height plus 2 in |
| Maximum area | 144 sq ft |
| Largest box | 10 in |
| Minimum width | 31 in overall |
The slat can cut those limits further. A 38 mm insulated spring shutter is held to that slat's 159 in width and 112 sq ft; a 63 mm single-wall spring shutter can use the full spring limits. The 55 mm insulated slat is not offered spring-loaded; it is motorized only.
Compared with the other manual operators, the spring reaches much further: strap, crank and wand shutters stop at a curtain of about 50 lb, while a spring shutter can cover 144 sq ft. Shutters over 6 ft ship with a pull-down hook, and the bottom bar has a hole for it. Where a spring shutter is too big, the answer is a motor; see how big a manual shutter can be.
What slats, locks and handles can I get?
It depends on the slat.
| 63 mm single-wall | 38 mm insulated | |
|---|---|---|
| Handle | Full-width aluminum L-angle on the bottom bar, so you can grab it anywhere | Handles fixed to the bottom bar |
| Lock | Key lock or thumb-turn lock that drives two pins sideways into the guide rails | Key lock, or slide locks (thumb-turn or slide bolt) |
| Finger slat | Available: a slat with a finger pull partway up, to start lifting without bending down | Not available |
On insulated (foam-filled) spring units, anti-lift brackets fitted inside the box stop the curtain being raised from outside; the kit's count depends on the shutter's size. Lock types and replacing them are covered on how rolling shutters lock.
Spring shutters are normally built with non-vented slats, because the spring can lift a closed curtain slightly and open light gaps in vented slats. At the sill they get a full-width L-angle instead of a U-channel; on 63 mm single-wall spring units the L-angle is optional.
How is the spring set, and how do I know it's right?
The spring is normally set on site, after the shutter is on the wall. Roll-A-Shield spring shutters ship with no tension in the spring, so it can be adjusted to that installation, and the kit includes two tensioning rods for the job. The exception is a unit on a 40 mm axle, which is pre-tensioned at the factory. The procedure is on how to tension a spring-loaded shutter.
You can judge the setting without touching the spring. Lift the shutter about halfway and let go, then try a few other heights:
| What it does | What it means |
|---|---|
| Holds where you let go, stays down when closed | Tension is right |
| Slides down, or feels heavy to lift | Too little tension |
| Opens too fast, creeps up, or won't stay closed to lock | Too much tension |
| Rolls up hard enough to catch your hands on the handles at the top | Too much tension |
Stop: A wound spring stores a lot of energy. Follow the tensioning guide exactly, or call (480) 921-0200. Following a published Roll-A-Shield guide does not void the warranty. Mains wiring must be done by a licensed electrician.
More symptoms and fixes are on spring shutter is too heavy, flies up or won't stay down.
When is a spring shutter the right choice?
When the opening is too big for a strap or crank, there is no convenient power, and someone will be there to open and close it by hand. A motor is the choice when the opening is larger than the spring limits, and near the coast, where Roll-A-Shield recommends motorized or single-wall shutters and does not recommend spring units. Motor options are compared on wired, radio, override, solar or battery.
Installing a spring shutter is like installing any other, plus the tensioning step; see the spring-loaded install guide. For a quote, send your opening sizes or call (480) 921-0200.
Watch it done
Product Overview – Spring Loaded
The written steps on this page are the reference; the video shows the same job.
Frequently asked questions
Do spring-loaded shutters need electricity?
No. There is no motor, wiring or power supply; the spring does the lifting and you open and close the shutter by hand, which suits storefronts and openings with no power nearby.
Can I buy a spring shutter now and add a motor later?
Roll-A-Shield does not sell shutters to be motorized later. Converting an existing manual shutter to a motor is a separate service job; call (480) 921-0200 to talk it through.
Does a spring shutter need stops to keep it from flying up?
Not when the spring is set right: it holds at any height, and at the top the full-width handle on a single-wall unit meets the lip on the bottom of the box. If it shoots up when you let go, the spring is too tight.
Are spring shutters a good idea near the ocean?
They are not recommended in salt air. Near the coast Roll-A-Shield recommends motorized or single-wall shutters, and a rust-mitigation treatment is available.
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.