Steel Back Boxes
Steel back boxes are flush-mounted metal boxes set into masonry walls to house switches, sockets and other wiring accessories behind the faceplate. We stock Zahler 1 and 2 gang galvanised steel boxes in 25mm, 35mm and 47mm depths, a Zahler 40mm side fixing box and a PEMCO 40mm single box with an adjustable lug.
The range also includes dual flush boxes, a 3 gang 1+2 box, a 6 to 8 gang pattress and back box repair clips. Buy at trade rates with a Meteor account and get next working day delivery on in-stock lines across NI and ROI when you order by 5pm.
Choosing the right steel back box
The back box sets the depth and position of every switch and socket you fit, so it pays to pick the correct size before the first-fix stage. Steel boxes are intended for solid walls such as block and brick, where they are chased in and plastered over.
Gang size and depth
Match the box to the faceplate: a 1 gang box for single switches and sockets, a 2 gang box for doubles, and dual or 3 gang 1+2 boxes for combined layouts. Depth matters just as much:
- 25mm suits standard plate switches and shallow accessories where wall depth is limited.
- 35mm is a common all-round choice for sockets and switches with a few cables.
- 40mm to 47mm gives room for fused spurs, dimmers, USB sockets and multiple cable entries.
Fixing and adjustment
Side fixing boxes let you secure the box through its sides where the rear of the chase is uneven. Adjustable lugs, like the one on the PEMCO 40mm box, help bring the faceplate level with the finished plaster. If a lug is damaged during renovation work, back box repair clips save cutting out the whole box.
Installation and safety
Fit grommets in every knockout used so cable insulation is protected from the steel edge. Metal boxes must be correctly earthed, so check current wiring regulations (BS 7671) and the accessory manufacturer's instructions for earth connections. For stud partitions and plasterboard, use PVC and dry lining socket boxes instead, and browse our switches and sockets for matching faceplates. PVC grommets are available separately.
Order with Meteor
From our Cookstown warehouse we carry 5,000+ products from over 100 trade brands. Free delivery starts at £30 / €35 ex VAT, Great Britain orders arrive in 3 to 5 working days, and products carry the manufacturer's warranty.
FAQ's
- What depth back box do I need for a double socket?
- Do steel back boxes need to be earthed?
- Can I use a steel back box in a plasterboard wall?
- How do I fix a back box that has a broken lug?
- What is the difference between a 25mm and 35mm steel box?
- How quickly can steel back boxes be delivered?