July 18, 2026 Shopify API

Click Mode Back Boxes — Pattress, Galvanised Metal and Dry Lining Boxes for UK Electricians

Back boxes are one of those unglamorous van-stock items every electrician orders by the box — yet choosing the wrong type for the substrate costs time on site. Click Mode offers a clear range covering three common scenarios: pattress boxes for solid masonry, galvanised metal back boxes for stud or exposed metalwork installs, and dry lining (plasterboard) boxes for partition walls. This guide walks through when to use each type and which SKUs to keep on the shelf.

Pattress Boxes — For Solid Masonry Walls

Pattress back boxes (also called surface-mount or flush-mount boxes) are the workhorse of domestic and light-commercial electrical installation. Click Mode's pattress range runs from 1-gang to 2-gang in depths of 25 mm, 29 mm, 35 mm and 47 mm. The shallower 25 mm depth is ideal where wall space is tight — particularly in older properties where the chase depth is limited — while the 35 mm and 47 mm options give you room for twin RCDs, smart dimmers, or a double USB socket module with rear cable management. All boxes are manufactured to BS 4662 and accept standard UK faceplate fixings at 60.3 mm centres (1G) or 120.6 mm centres (2G).

Key installation tip: always check the depth before ordering. A dimmer module feeding an LED driver typically needs at least 35 mm behind the faceplate to avoid heat build-up. If you are converting an old radial to a ring final, the extra depth also helps when back-feeding twin 6 mm² cable into a single back box.

Galvanised Metal Back Boxes — For Stud Walls, Furring and Surface Wiring

When the wall is steel-stud partition board, a timber-framed extension, or where the box will be surface-mounted on an exposed brick or block finish, a galvanised steel back box is the correct choice. Click Mode's galvanised range spans 1G and 2G in 25 mm and 47 mm depths. The earthing lug is factory-installed, satisfying BS 7671 requirement to earth metalwork, and the knock-outs are pre-scored on three sides for fast cable entry without a hammer drill. Because the box itself is conductive, accidental contact between the cable sheath and box does not create an insulation fault — an advantage in humid utility rooms where conduit installations are common.

On exposed brickwork or block, simply chase in a 25 mm groove and fix with screws into wall plugs — the galvanised finish resists rust in bathrooms and kitchens where plaster has not yet been applied. Remember that a metal back box must be connected to the circuit protective conductor (CPC) via the earthing terminal before the faceplate is fitted.

Dry Lining Boxes — For Plasterboard Partition Walls

Dry lining boxes (also called cavity wall or plasterboard boxes) use expanding lugs or plastic wings to grip the back face of plasterboard, eliminating the need for noggings or an adhesive set. Click Mode's dry lining range covers 1G and 2G in 35 mm and 47 mm depths. The deeper 47 mm option is particularly useful where first-fix cable is looped via junction boxes inside the cavity — it gives the second-fix electrician room to fold back the cable tails without kinking. The click-in wings can be adjusted with a screwdriver from the front, so you can tighten or remove the box without cutting into the plasterboard face.

Plasterboard dry lining boxes are not suitable for damp locations. In bathrooms, use a pattress box set into a timber nogging in the stud, or a galvanised back box where the wall is tanked. Also check that the box edges are flush with the finished surface — plasterboard with a skim coat adds roughly 3–5 mm, so you may want to specify the 47 mm depth to allow for a skim or tape-and-joint finish.

Depth Reference Table

Application	Recommended depth
Standard switched socket (1G or 2G)	25 mm pattress
Dimmer switch, smart module	35 mm pattress
USB socket, twin-module	35 mm or 47 mm
Stud / metal frame wall	25 mm galvanised
Plasterboard first fix (standard socket)	35 mm dry lining
Plasterboard with skim / tape-and-joint	47 mm dry lining

Pattress Box vs Galvanised Box vs Dry Lining Box — Which to Stock?

A well-stocked electrician's van typically carries all three types. A useful starting rule is:

Solid masonry (brick, block, concrete): pattress box in 25 mm for sockets, 35 mm for dimmers
Steel stud or timber frame: galvanised 25 mm for surface wiring, galvanised 47 mm for first-fix in a framed partition
Plasterboard (dry side): dry lining 35 mm for standard sockets, 47 mm where a skim is expected

On new-build sites where all three substrates appear in the same property, carrying a mixed pallet of Click Mode back boxes by the 10-pack or trade box is the most economical approach — especially given the per-unit prices below £2 for most of the standard depth pattress range.