How to Measure for a Shower Enclosure or Shower Door

You need a steel tape, a spirit level (the longer the better) and a pencil. Measure in millimetres, because that's how every door, panel and tray is sized.

Measure once the tray is in and the walls are tiled or panelled. Tiles and adhesive, or wall panels, add thickness to each wall and can easily take 20mm or more off the width of the opening, and the glass fits against the finished surface, not the bare wall.

Then decide the layout. In a recess, with walls on three sides, you only need a door. In a corner, with walls on two sides, you need a door and a side panel, or a quadrant, offset quadrant or corner entry enclosure. For a walk-in, a wetroom screen needs no door at all.

1. Measure the tray. Length and width across the top, in mm. A standard tray will match one of the sizes in our shower tray sizes guide, and that's the door size you start from.
2. Measure wall to wall at three heights: just above the tray, at waist height and near the top of where the door will reach. Write all three down.
3. Use the smallest figure. The door has to fit the tightest point of the opening.
4. Check the walls with a spirit level. If one leans, the gap between your top and bottom figures tells you by how much.
5. Check the adjustment range on the product page: your smallest measurement must fall inside it, and so must the largest.
6. Measure the height. ICON doors are 1850mm (6mm glass), 1950mm (8mm) or 2000mm (Phantom). Check under sloping ceilings, beams and window sills.
7. Check the clearance outside. Hinged and pivot doors swing outwards, so make sure the door clears the toilet, basin, radiator and the bathroom door.

Wall profiles let a door or panel fit openings slightly smaller than its nominal size, to take up walls that aren't straight. Some real examples from the ICON range:

So most ICON doors adjust 40mm, and side panels and enclosures about 20mm. A few lines differ, so always check the figure on the product page of the one you're buying.

If a wall is further out than that, or the opening is just too wide, an ICON extension profile fits behind the wall profile and adds 20mm or 30mm on 6mm glass, or 25mm or 30mm on 8mm, from £38.79. For a recess wider than the biggest door, a 200mm ICON inline panel (£132.88) sits beside a 6mm sliding, bifold or pivot door to fill the gap.

In a corner the door goes on one side of the tray and a side panel on the other, and each is sized to its own side. Pick the door for the side you want to walk in from and the panel for the other: a 900 x 800mm tray takes a 900mm door and an 800mm panel, and a 1200 x 800mm tray takes a 1200mm sliding door and an 800mm panel.

Measure along each wall from the corner to the outside edge of the tray, at the bottom and the top, and check each figure falls inside the range of the piece going on that side. The door and panel must come from the same ICON range, in the same glass thickness and finish, because they're made to join at the corner.

A quadrant enclosure is made for its matching tray, so an 800 x 800mm quadrant goes on an 800 x 800mm quadrant tray. Measure along each wall from the corner to where the tray's curve meets the wall. ICON quadrants adjust about 20mm on each wall: a 900 x 900mm enclosure takes 870–890mm.

Because a quadrant's curve is fixed, the corner has to be close to square. Check it with the 3-4-5 rule: mark 300mm along one wall and 400mm along the other, and the diagonal between the marks should be 500mm. If it's well out, come and talk to us before you order.

An offset quadrant has a long side and a short side, so measure both. ICON offset enclosures are reversible, but the trays are made left or right handed, so check the maker's drawing to order the tray the right way round.

A bath screen sits on the bath rim against the wall. Check the rim is flat where the screen will stand, and that the wall above it is flat enough for the wall profile. ICON single screens are 800mm wide and 1400mm high; the double screens are 900mm wide and 1500mm high and fold to shield a wider area. They start from £84.38.

Make sure the glass clears the taps, the shower valve and any riser rail as it swings in over the bath. An L-shaped shower bath needs the screen made for it — the SCN L-shaped screen is £142.58.

Not sure of a measurement? Bring a sketch with your figures to our Chingford counter: the staff are tradespeople and will check it against the range before you buy. Unused items can be returned within 30 days, and shower glass goes by fragile-goods courier for £29.99 per order.