To measure and order replacement ceiling tiles, you need to determine module size, edge detail, and grid type for your existing tiles, and then find a match in a current product. If you get these three factors correct, the new tiles will simply drop into the existing grid with no cutting or surprises. If you get them incorrect, you will receive tiles that sit proud of the grid, rattle, or do not fit at all. This guide will describe the measuring process how an experienced fitter would do it on site.
Step one: measure the tile instead of the hole.
Always remove an existing tile to take measurements of the tile itself, not the grid aperture. In the UK, nominal sizes are given in millimetres. The two sizes you will encounter almost every commercial job are595mm x 595mm (the modern metric square) and 1195mm x 595mmThey are located on a grid constructed on 600mm and 1200mm centers, the 5mm difference being the clearance the tile must have to drop in and be lifted back out.
If your tile measures closer to 600mm x 600mm or 1200mm x 600mmYou are likely working with an older imperial-era ceiling or a square edge tile that fills the full module. This is important because ordering a 595mm tile for a true 600mm aperture leaves a gap on every edge. RCT stocks both metric and imperial sizes because so many older UK buildings still run on the original module.
Step two: identify the edge detail
Most mismatches occur at edge detail. Typically, there are three common profiles:
When holding a tile on its edge, the profile can be viewed under the light. If a tile has a square edge, it is a flat rectangle. In the case of a tegular or microlook tile, there is a noticeable rebate on the back face.
Step three: check the grid width
View the exposed face of your grid bars. A standard exposed grid is24mm wide. A slimline grid is 15mmBecause tegular tiles are made uniquely for each size, a 24mm tegular tile won’t seat correctly into a 15mm grid. Therefore, if you are only replacing tiles and leaving the grid as is, make sure to align the tiles with the grid you currently have.
Step four: count, then add a margin
Calculate the area of your room and divide that by the coverage of a single tile. For example, a 595mm x 595mm tile covers about 0.354m², therefore, a box of 16 tiles covers roughly5.76m²When handling tiles, it’s a good practice to always order an additional 5-10% to allow for those found at the perimeter, future breakages, and any damaged during handling. On a refurbishment of an area that disturbs the ceiling, ordering the maximum of that range is justified, as tiles that have been in place for years tend to crumble at the edges when they are lifted.
Step five: if possible, try to identify the brand and the pattern.
The building owners who wish to have seamless matching across the existing ceiling will need to consider brand and surface pattern. The most commonly installed brands in the UK areZentia (formerly Armstrong), Knauf AMF, British Gypsum, Rockfon and EcophonSeveral tiles have a product code printed on the back — please photograph this. If the original tile has been discontinued, a specialist supplier can often determine the closest current equivalent from a good photograph of the face pattern and edge.
Frequently Asked Questions
The standard size of suspended ceiling tiles in the UK is usually 600mm x 600mm.
There are two standard metric sizes. 595mm x 595mm and 1195mm x 595mm, which fit grids built on 600mm and 1200mm centres. RCT also stocks imperial 600 x 600mm and 1200 x 600mm sizes that older buildings may use.
How can I tell if I have a 15mm grid or a 24mm grid?
Determine the measurement of the visible metal side of the grid bar. A regular grid face has a width measurement of 24mm, while a slimline grid has a width measurement of 15mm. Match the tiles to the grid you will be retaining, as tegular and microlook tiles will be trimmed to accommodate one option or the other.
How many tiles are in a box?
A standard tile box contains 16 tiles and covers about 5.76m². The size of each tile is 595mm x 595mm. Due to differing box quantities based on product and thickness, please reference the product page prior to ordering.
Am I able to change only a couple of damaged tiles?
Yes. If you know the size, edge detail, and pattern of the tiles, individual replacement tiles can be matched to an old ceiling. RCT can match discontinued items by the tile face.
For edge details, brands, and sizes, you can view ourSuspended Ceiling Tiles category— the largest online stock of replacement tiles in the UK.
If you’re not sure what you are looking at, you can send us a photo or call the team at01939 251 450, and we will identify your tile and check the stock before you make your order.Request a bulk quote for larger jobs.
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