A shower enclosure needs to suit the finished opening and its exact product specification. A nominal tray size is useful starting information, but it is not a complete order instruction for every screen or door.
Collect the exact product information
Record the enclosure manufacturer, range, model, door arrangement and matching tray reference. Obtain the current drawing and fitting instructions. Similar-looking products can have different adjustment ranges, fixing arrangements and component requirements.
If the room is being retiled or panelled, tell the supplier how the wall finish is changing. Ask when the final measurements can be confirmed and who should take them. Keep an early quotation size separate from the dimensions approved for purchase.
Measure the opening at the right stage
MERLYN’s fitting guidance asks customers to check that the final wall-to-wall tile measurement falls within the selected enclosure’s adjustment range. Apply the instructions for the chosen product, because its stated nominal width may not equal the finished opening.
Ask the installer to record relevant measurements and any out-of-plumb condition. Do not assume a product adjustment range can correct every irregular wall or unsuitable tray. Where the finish is incomplete, record what still needs to happen before the order is released.
Check how the door will move
Mark the proposed opening direction and the space needed around the door or sliding panels. Consider the basin, toilet, towel rail, handles and the route into the room. A product may fit the wall opening and still have a door that is inconvenient in your layout.
Use a simple plan to compare options. Product selection for an accessibility requirement needs its own project assessment. An enclosure that fits does not automatically provide a suitable accessible shower.
Enclosure purchase record
| Record | What to confirm |
|---|---|
| Model | Manufacturer, exact enclosure/door/tray references and current instructions. |
| Finished opening | Checked dimensions, wall condition and relevant adjustment range. |
| Movement and interfaces | Door direction, nearby fittings, handles and access. |
| Supply decision | Final measurement owner, order approval, delivery check and making good. |
Inspect the retained tray and surrounding finish
If only the enclosure is changing, ask the installer to assess the retained tray, wall fixings and adjoining seals. Record damage or existing leaks. Removal may expose marks or fixing holes that the new profiles do not conceal.
Agree the extent of making good before ordering. Distinguish fitting the new enclosure from replacing the tray, repairing the background or changing the waterproofing arrangement. Any unresolved defect should remain visible in the scope.
Example: nominal sizes that look the same
Two enclosure descriptions may use the same nominal size while their published adjustment ranges differ. In this unpriced example, the owner sends both model drawings to the installer and supplier. They check the finished opening and confirm the suitable choice before purchase.
For a quotation, send photographs, tray details, approximate opening dimensions and the preferred product. Explain whether tiling or wall panels are changing and who supplies the enclosure. Keep the final checked model and measurement record with the bathroom documents.
Useful next steps
Sources and product information
Have a project in London or the surrounding areas? Send us your project brief, with photographs and the decisions you have already made.