Jim Percival, technical director at Palace Chemicals, explains what fixers need to know about the growing trend for large format tiles
It will not have escaped anyone’s notice that tile sizes are increasing. Large porcelain panels are now seen in both commercial and residential installations. The bigger the tile size, the more dramatic the statement that can be made on many tiling jobs, particularly when allied to the fashionable concrete or industrial look.
The main reason for their popularity is that they offer a no-nonsense, sleek and unfussy aesthetic. This is due to the fact that large format tiles and panels have fewer grout lines, allowing a clean and uninterrupted finish. When used in bathrooms, kitchens and other hygiene-sensitive environments, this also means easier cleaning along with health and wellbeing benefits.
In the British Standard BS 5385 Part 1:2018, the definition of a ceramic panel is a tile with a surface area >1sqm, with any tile edge >1,200mm, whereas a large format ceramic tile is defined as a ceramic tile with a surface area greater than 3,600sqcm, but no tile edge greater than 1,200mm. Meanwhile a large format ceramic panel has either a surface area greater than 1sqm or any edge longer than 1,200mm.
Handling tiles or panels of this size presents a number of challenges for the tile fixer. Firstly logistics: getting the materials to site and having enough space to store the crates or ‘A’ frames they come in is one issue. Even with a telehandler on site, the forks must be adjusted to the width of the supports on the crates. The panels should not be stacked against a wall without use of any lifting aids or frames.
Problems can occur when the panels are sold to customers, without any consideration for access, especially if they are being used in an upstairs location. This may be OK on a new build, however on refurb work a lot of staircases only allow a maximum size of 900mm x 2.4m. Since the standard panel sizes are 2.4m x 1.2m and 3m x 1m and above, this can clearly present a problem and might call for the use of an alternative method, such as the use of external scaffolding platforms and gaining access by removing windows.
It is also important that appropriate trowels and techniques are used when laying an adhesive bed and back buttering panels. Walls need to be plumb and square prior to installation of the panels, and floors need to be as flat as possible. Issues can arise where the floors are of a reasonable standard for normal flooring but don’t meet the rquirement to achieve solid bedding with large porcelain panels.
Large format tiles and panels should be laid to a minimum surface regularity of SR1, in accordance with BS8204, which means a maximum gap of 3mm over a 2m length. Grout joints should be a minimum of 3mm wide, together with expansion joints where needed. Joint widths need to be increased pro rata according to panel size. So for instance the minimum joint width for a 3m long ceramic panel is 5mm.
There are also requirements regarding the fixing of large panels. These are included in the recently published version of the British Standard relating to tiling in Section 2 parts 7.2.3 and 7.2.4 of BS 5385 Part 3:2024. This states that: “Thin ceramic panels should be handled with specially designed equipment for supporting them in order to prevent possible fracture during and after removal from the manufacturer’s original packaging, as well as for the actual installation of the panels.
‘Depending upon the size of the panel, sufficient bedding adhesive should be spread to install one panel at a time to avoid possible “skinning” of the adhesive which could have a detrimental effect upon the performance of the adhesive bond.
‘Where tiles greater than 0.1sqm face area are required to be fixed to walls above 3m above floor level they should be secured by mechanical fixings.
‘Where tiles are to be mechanically fixed the background should be sufficiently robust to take the method of attachment.” Tiles and panels in these types of installations should be mechanically fixed to a supporting metal framework by means of special clips or anchors which are fitted to undercut slots or holes formed in the back of the ceramic tiles or slabs. Various types of proprietary support and mechanical fixing systems are available for this purpose.
For tiles that are not being fitted at height, of course the choice of adhesive is important to ensure that a solid bed is achieved, which will require applying adhesive to the substrate and also back-buttering the tiles. Particular attention should be paid to the application of adhesive to the backs of thin ceramic tiles and panels so that the edges and corners are properly covered with adhesive.
Another issue is that flexibility is required. When fixing to floors, a suitable cementitious adhesive according to BS EN 12004 should be used.
When fixing to walls a C2 S1 cementitious adhesive according to BS EN 12004 is recommended, particularly when fixing porcelain tiles. In both instances advice should be sought from the adhesive manufacturer. It is important to note that dispersion adhesives, which require the presence of air to cure, are not suitable for large format tiles and should not be used to fix them.
At all times be aware of manufacturers’ recommendations regarding adhesive selection and also trowel type for application.
www.palacechemicals.co.uk
