Surface Mounting Blocks 101: Benefits, Types and Materials Explained

 The simplest components are sometimes the most important and one of the most fitting examples of this is an electrical box. Also called a surface mounting block, a wall box is used to provide a safe and adequate amount of space for the wiring of outlets, switches and light fixtures.

Not using an electrical box is not only unsafe practise but it's also illegal especially if you've used it incorrectly. Too many wires inside it is a big no-no. Mounting blocks are made of different materials and serve different purposes depending on the application.

Benefits of Mounting Blocks

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Protection

Wherever they're installed though, electrical wall boxes are first of all there to protect both the outlet or switch and the user from each other. A person might get an electric shock without a proper surface mounting block in place and the wiring behind the box can get damaged if tampered with by inexperienced personnel. Safety goes both ways here.

Appearance

Another reason why an electric mounting block is found on every power point is that it makes it look much better. Without a mounting block, all the exposed hardware and wires just make your home look like it's in the middle of a renovation.

Access

Although the wiring of an outlet or switch is hidden behind a piece of metal or plastic, that doesn't mean that you can't get to it. In fact, it's rather easy to get to them as the mounting box is easily removed with a flat screwdriver. When done, all you need to do is push the mounting box onto the outlet or switch and it clips in place.

Materials of Mounting Blocks

PVC

The overall consensus on electrical box materials is that PVC or plastic boxes are the go-to option for many when it comes to indoor use. They can be used outdoors but they need to be made with threaded hubs, coupled with non-metallic conduits. PVC boxes are also the most affordable of the bunch.

Steel

The best protection you can get for indoor outlets and switches is with steel boxes. They go well with all kinds of conduit as well as metal-clad cables since you can use a steel electrical mounting block with non-metallic sheathed cables. Be wary not to connect steel boxes to the grounding system of your home as they are conductive. 

Cast Aluminium

Although cast aluminium boxes are conductive too, they are better for outdoor use than steel ones as they don't rust as easily when exposed to the elements. They offer the same benefits as steel boxes and can be used with the same cables and conduits.

Fibreglass

When it comes to non-metallic sheathed cables found indoors, fibreglass wall boxes are the best. Anything else though and you should look for any of the above types of electrical wall boxes.

Types of Surface Mounting Blocks

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Switch

As you'd expect a switch box is made to house the hardware and wiring of a switch and to keep it on the wall securely. A switch box is used only for in-wall installations with older designs being best for existing covered walls and newer designs for more concealed solutions.

Outdoor

Outdoor or weatherproof electrical wall boxes are made to survive through the most extreme weather conditions. They are available in both single and two-gang designs and you can find them with a round shape.

Junction

A junction electrical box is one made to cover wire splicers. This is the standard 10 cm box made out of either plastic or steel that has lots of space and it's the easiest to work with in a wide range of applications.

Square

With a square mounting block, you can provide protection and appeal both in on-wall and in-wall setups. They are available in two sizes one is the standard 10 cm and the other is with a depth of 5.5 cm. 

Handy

Also called utility boxes, handy electrical boxes are made for indoor use and to install any outlets and switches on an exposed surface. There are handy boxes that come with a mounting bracket to attach them to a wall or ceiling.

Ceiling

Talking about ceilings, there are ceiling boxes that are made to be lightweight and accommodate the wiring of ceiling lights. A ceiling box can be either round or hexagonal.

Floor

You can also get a floor electrical mounting block which is able to provide the same benefits as those of a ceiling box just in a different package. A floor box is adjustable so that it fits different floor thicknesses.

Round Pan

Also referred to as pancake wall boxes, round pan boxes are also used for ceiling-mounted light fixtures. They can support a weight of up to 22 kg and are anywhere between 1 cm and 2 cm deep

Extenders

A box extender is solely used to make more room on existing wall boxes. Also called extension rings, they come in all shapes and sizes they are placed on the front and can also make an existing box sit flush with the surface it's mounted on.