What an automatic shutter is made of

Six assemblies, and the price of a shutter is mostly decided by two of them. A working note on what is actually in a quotation.

An automatic roller shutter is six assemblies: the slat curtain, the operator, the battery back-up, the flange drive that couples motor to barrel, the obstruction cut-out, and the barrel with its guides and brackets.

A quotation is dominated by two of them. Curtain area sets the slat cost and, because the operator is sized on curtain mass, it sets the motor as well. The rest — flanges, cut-out, control box, handsets — moves comparatively little between a small door and a large one.

That is worth knowing before comparing two quotations. A cheaper price on the same opening usually means a thinner slat, and a thinner slat means a lighter curtain, which means a smaller motor: the saving compounds down the specification and lands as a door that cycles slower and wears faster.

Shutters are classified four ways in ordinary use: by slat form (single-skin, vented, wide-span), by function (domestic, industrial, fire), by drive (hand, DC with hand lift, AC, three-phase), and by where the barrel sits (in the head, above the ceiling, on the face).