Don’t Be At A Loss With Marble Installation
Colin Stanyard on installing ceramic and stone finishes
LAST month in CFJ, I discussed the importance of selecting the correct adhesive for installing tiles, notably ceramic surfaces.
Of course, not all tiles fall under the ceramic umbrella. Natural stone is extremely popular too, with marble, travertine, limestone and slate widely available.
The main difference between natural stone and ceramic tiles is how they can behave during and after installation. The characteristics of natural stone vary depending on its constituent parts, which fluctuate even within a category, depending on its geographical location.
It’s important to check with your supplier to establish whether the particular stone has any application restrictions.
Certain types of stone may be prone to staining, or warping when heated, or when in contact with water.
In many cases, specially formulated rapid setting adhesives can minimise the quantity of water which can potentially be absorbed into the stone, thus reducing these risks.
As an alternative to natural material, resin-bonded agglomerate stone tiles, with their regularity and different aesthetics, like glitter effects, provide other options. Note that these tiles can curl when exposed to heat or moisture. It is, therefore, essential to consult your supplier and/or adhesive manufacturer before installation.
Other more niche types of ‘tile’ exist and this article wouldn’t be complete without mentioning glass tiles and mosaics, and metallic mosaics.
Pure glass tiles are readily bonded with many adhesives, but many glass tiles and mosaics have a back coating to provide colour.
These backings are often resin based which require modified adhesives to fix them; including polymer modified cement-based adhesives to epoxy or polyurethane adhesives, depending on the nature of the coating.
Metallic mosaics aren’t usually difficult to bond as the rear is usually ceramic, with only the face being metallic. The main concern here is the grouting process; in general, a fine grain grout is needed.
As an industry, we have gone to great lengths to ensure adhesives meet certain criteria.
The European Standard (BS) EN 12004 classifies adhesive performance which should not be ignored when making your selection. All tile adhesives available in the UK must comply with this standard and all packaging should be clearly marked to show this compliance.
Symbols such as, C2TE S1, should be displayed. Many of you reading this already understand the symbols and their significance, but I’ll recap briefly:
The type of adhesive is denoted by a C, D or R for cement-based, dispersion-based (ready mixed) or resin based (epoxy or polyurethane).
The adhesive type identifier is then followed by a number 1 or 2. Number 1 is a normal adhesive fulfilling the fundamental requirements, with 2 denoting an improved adhesive meeting additional requirements. With dispersion adhesives, improved characteristics would be adhesion strength after immersion in water.
F refers to fast setting, T to slip resistance and E to extended open time. S1 and S2 are measures of deformability within an adhesive, with S2 classed as highly deformable.
Deformability classification is only currently applicable to cement-based adhesives. This is a much-simplified overview of the standard, with adhesives undergoing many rigorous tests to achieve the classification allocated.
How can these symbols help when choosing an adhesive to fix tiles?
As a simplistic approach, a C2 adhesive should be selected for a porcelain tile; an F where natural stone is being fixed, or where the area needs to go into service quickly; an E where temperatures are high or substrates particularly absorbent, and an S1/S2 adhesive with underfloor/undertile heating, or on substrates subject to vibration or limited deflection.
Colin Stanyard is ceramic product manager, Mapei UK