450 x 450 Access Panels

Four hundred and fifty millimetres square is the middle of the range and, for a lot of maintenance work, the practical minimum. It gives room for a hand, a forearm and a tool at the same time, which is the difference between reaching a valve and being able to turn it. Sight lines are good enough to inspect a connection properly, without resorting to a mirror and a torch held at arm’s length.

This is the size that tends to get chosen for isolating valves on a heating or water circuit, electrical isolators, meter connections and tails, filling loops, and gate valves on a branch off a riser. In a wall it lets a technician work on a fitting head on rather than blind. In a ceiling it is usually small enough to sit within a single bay, so the opening disturbs no more of the board than the job requires.

What it will not do is give body access, and the door is not intended to be stood on or leant against. If the work needs a person or a bulky component through the aperture, size up or look at a purpose built hatch instead.

Order by the panel size you want, then cut the hole a little larger so the frame seats without being forced. Each product page gives the structural opening for that panel. Work to that figure rather than a rule of thumb, since the allowance varies by range and by frame style, and a hole cut too tight has to be opened up again on site.

Two checks head off most of the trouble at this size. First, look for studs, joists, cables and pipework in the line of the cut: 450mm is wide enough to catch a member you were not expecting, particularly in a stud wall. Second, settle the frame style before the saw comes out, because it changes how the edge has to be prepared.

A picture frame sits proud of the finished surface and covers the cut edge, which is forgiving on a wall that has already been decorated or tiled. A beaded frame is meant to be filled and finished up to, so the panel sinks into a skimmed or boarded surface and reads as a line rather than a fitting. Neither is better in the abstract, they suit different points in the programme. Fitting after the room is finished usually points to the overlapping option.

The 450 x 450 listing covers metal door panels, plasterboard faced panels and fire rated versions of both. At one hour, you can have a steel faced door or a plasterboard faced door, in either frame style. At two hours, the option carried here is a steel door in a beaded frame. Ratings belong to a tested construction and orientation rather than to a size, so check what the specification asks for before choosing between them. The complete rated range is under fire rated access panels.

Where the panel is not doing a fire job, the choice is about wear and appearance. A steel door takes repeated opening in a plant space or a cupboard visited weekly. A plasterboard faced door decorates in and suits a living space. A budget specification metal door is listed at 450 x 450 with a picture frame, for openings that are out of sight and jobs where cost decides. If the location is a low traffic domestic cupboard and a different material would do, compare plastic access panels before you commit to this size.

Where several panels of the same specification are going into one contract, multipack pricing is offered on selected lines in discounted multipacks.

Buyers at this size are usually deciding between a rated and a standard panel, or working out whether the aperture is generous enough for the service behind it. The answers below cover what we are asked most often. If your question is not here, the full list sits on the access panel FAQs page, and our team can check a specification with you before you place the order.