Coram Shower Enclosures Explained: Optima 6, Premier 8 and GB5 Compared

Coram Showers has been making shower enclosures in Bilston, in the West Midlands, for over 50 years, and the current line-up comes down to three ranges. They look similar in a photo. In the room they are different products at different prices, and the right one depends on the ceiling height, the walls, the budget and how much you care about the finish.

This guide sets the three ranges side by side, then walks through the door types and how to turn a single door into a complete enclosure.

The three ranges at a glance

All three have Coram's stay-clean glass coating as standard, ultra-clear soft seals, fully concealed fixings and CE testing to BS EN 14428. All three fit on a shower tray or straight onto a wetroom floor, and every door is reversible for left or right hand.

Optima 6: the one to look at first

Optima 6 is the mid-range and the one most people end up with. It is 1900mm high in 6mm glass, which is the sweet spot for a domestic bathroom: tall enough to contain spray from a rainfall head, light enough that the door swings and slides easily and does not need heavy-duty hinges.

It is also the only Coram range in finishes other than chrome. Pivot, sliding and quadrant doors come in Chrome, Brushed Black and Brushed Gold, with side panels to match, so a black or brass-look enclosure can be had without paying for a designer brand. The bi-fold is chrome only.

The Cam and Pin system means the door arrives pre-assembled and clicks together on site, and Level and Lock adjustment lets you plumb the door without screws through the profile. For a fitter that is an hour saved. For a homeowner it means fewer things to go wrong.

Premier 8: the heavyweight

Premier 8 is the top of the range: 2000mm high in 8mm glass. The extra 100mm of height matters in a room with a high ceiling or a tall user, and the 8mm glass gives the door a solid, expensive feel when it closes. The sliding door has soft close and soft open with double-bearing rollers set flush to the glass, which is the difference between a door you slide and a door that glides.

Premier 8 is chrome only, but it has two enclosures the other ranges do not. The corner entry has two sliding doors that meet at the corner, so nothing swings into the room. The double bi-fold is a pair of doors that fold back flat to the walls and open outward, which gives the widest possible access into the shower. That is the enclosure specified for assisted showering, and it can be ordered with a coving profile kit so it fits over a vinyl wetroom floor without cutting the vinyl.

GB5: the contractor's range

GB5 is 1800mm high in 5mm glass and it is the value range, built for housing associations, landlords and anyone fitting a lot of bathrooms. Two things make it worth a look beyond the price.

The first is the height. 1800mm suits a bathroom with a low ceiling, a sloping ceiling under the eaves, or a bulkhead over the shower. The second is 25mm of adjustment per profile rather than 20mm, which is the difference between a door that fits an old, out-of-true wall and one that does not. GB5 comes as pivot, bi-fold and sliding, all chrome, with a side panel to match.

Which door type?

Pivot

A single door on a rise-and-fall hinge, swinging outward. The simplest door and the cheapest, and the offset pivot means it needs less swing room than you would think. Best for an alcove of 700mm to 1000mm, or a corner with a side panel.

Bi-fold

Folds inwards on itself, so it needs no swing room outside the enclosure at all. This is the door for an en-suite where the toilet or basin is right in front of the shower. The trade-off is a slightly narrower opening than a pivot of the same width.

Sliding

For openings of 1000mm and up. No swing room needed and a wide opening, and the doors lift off the track for cleaning. Premier 8 adds soft close.

Quadrant

A curved corner enclosure with two sliding doors, for a corner where a square enclosure would take up too much room. It is a complete enclosure in itself and sits on a matching quadrant tray. Optima 6 only.

Corner entry and double bi-fold

Premier 8 only. Both are two-sided enclosures for a corner with the opening at the corner itself. The corner entry slides; the double bi-fold folds out of the way completely.

Alcove or corner: the side panel

A shower door on its own fits an alcove, with a wall on both sides. In a corner you need a side panel: a fixed glass return that closes the open side. Every Coram door page on our site has a side panel dropdown, so you pick the door width, then the side panel width to match your tray depth, and the whole enclosure goes in the basket as one line. Pick the panel in the same finish as the door.

One thing to know: fitting a side panel reduces the door's adjustment range by 20mm, because the panel takes one of the door's wall profiles. Check the adjustment figures on the product page against the width you have measured.

For a three-sided enclosure, where the shower stands against one wall only, you need two side panels plus a pair of glass-to-wall fixing brackets. Those are in the Optima 6 accessories for Optima 6 and Premier 8, and in the GB5 side panel listing for GB5.

When the door is not wide enough: in-line panels

If the alcove is wider than the largest door, an in-line panel fills the gap. It is a fixed glass panel with a bracket that sits alongside the door on the same line. Optima 6 and Premier 8 both have them in 200mm, 400mm and 600mm, so a 1000mm door plus a 400mm panel covers a 1400mm alcove. A 20mm extension profile is there for the last few millimetres.

Measuring

Measure the opening at the height the door will sit, in three places, and use the smallest figure. Every door has a stated adjustment range, for example 755mm to 795mm for an 800mm pivot. The measurement has to fall inside that range. If it falls between two sizes, the smaller door with an extension profile is usually the better answer than the larger door forced in.

Measure the tray depth as well if you are adding a side panel; the side panel width is chosen to match it.

Which one, then?

• Standard bathroom, want a choice of finish: Optima 6.
• High ceiling, want the door to feel substantial, or need a corner entry or double bi-fold: Premier 8.
• Low ceiling, uneven walls, or fitting a lot of them: GB5.

Where to start

Browse the full range in the Coram collection, or go straight to pivot, bi-fold, sliding and quadrant doors. Pair the enclosure with a Coram stone resin tray, which is made to the same sizes.

If you have an opening measurement and are not sure which door fits it, send it over with the tray size and we will tell you.