Galvanised Roller Shutter Doors

Galvanised roller shutter doors are the default specification for any opening exposed to weather, salt air or regular washdown. The zinc coating is bonded to the steel rather than sprayed over it, so a scratch that reaches bare metal still will not spread rust the way a painted door does.

Where galvanised makes the difference

Inland, in a dry warehouse, a powder-coated door will last a long time. On the coast, in a food plant that gets hosed down nightly, or on a mine site with airborne chemistry, it will not. We specify galvanised slat as standard for anything within roughly 30km of the coastline and for any opening that gets washed.

Specification

• 0.8mm to 1.2mm hot-dip galvanised steel slat, depending on the span
• Galvanised guide rails, bottom rail and barrel assembly — not just the curtain
• Openings to 8 000mm wide
• Manual chain hoist, or three-phase motor with manual override
• Optional powder-coat topcoat over the galvanising where you want a colour match

A note on the cheaper version

There is a real difference between a hot-dip galvanised curtain and a pre-galvanised sheet that has been rolled after coating. The second is cheaper and the cut edges are bare. We use it only where the door is genuinely indoors and dry, and we will tell you which one we have quoted.

Send us the opening width and height and where the building is, and we will tell you honestly whether you need galvanising or whether you would be paying for protection you will never use.

Why galvanised, specifically

Galvanising bonds zinc to the steel metallurgically rather than laying a coating on top of it. The practical consequence is what happens at damage: a scratch through paint exposes bare steel and rust spreads sideways beneath the coating, while a scratch through galvanising is protected by the surrounding zinc, which corrodes sacrificially instead of the steel.

That difference decides doors in three environments. Within about 30km of the coastline, salt attacks painted steel at every cut edge and fixing point. On any door subject to washdown, chemical cleaning agents strip paint from the edges inward. In cold storage, condensation keeps steel permanently damp.

Painted steel remains perfectly sensible on a dry, sheltered internal opening where colour matching matters. Everywhere else, repainting on a two-year cycle costs more over a decade than specifying galvanised once.

How we build it

Every door is manufactured to your measured structural opening at our own works, not cut down from a stock size. Slat is roll-formed on our own line, guides are cut and drilled to the opening height, and the springs are wound to balance the finished curtain weight. Powder coating is applied after fabrication so the colour holds across the whole assembly rather than just the visible slat.

What decides the specification

Two things: the width of the opening and how often the door moves. Spring life is measured in cycles rather than years, so a door opening forty times a day needs a different spring and drive to one opening twice, even at identical dimensions. After that it is environment — salt air, washdown, dust or forklift traffic each change the material and the hardware. That is why we survey before quoting.

Installation and handover

Fitted by our own teams, never subcontracted. Guides are set plumb and square, the curtain is hung and balanced, limits are set, and every safety device is tested and adjusted within safe closing force before we leave. You get a demonstration of normal operation and of the manual override, because the first time you need that override should not be during an outage.

Warranty and aftercare

Workmanship is covered for twelve months and motors carry their manufacturer warranty, which we register for you. Because we manufactured your door, we can tell you its exact specification years later and we hold the wear parts for it rather than ordering them in — which is the practical difference between a repair that happens this week and one that waits on a supplier.

On the coast a galvanised roller door outlasts a painted one by years. Salt air finds the cut edges and fixings of ordinary roller shutters within a season, and once rust bleeds through the coating there is no repair that lasts.