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How to fix natural stones

 

 

Case

Different type of stones

Limestones, granite, marble, slates…Each type of natural stones has it s own technical or aesthetical characteristics, and their composition can vary a lot compared to standard ceramic tiles. Fixing stones thus requires special care and ap­plication methods.

Identification of the product being installed is essential to allow for the correct preparation and application.

In this Case/Solution, we will not speak about reconstituted/ artificial stones that have a different composition and need other technics and products (fast-setting adhesives,...etc)

 

 

Not all natural stones have the same characteristics

Mechanical characteristics, hardness, cohesiveness of natural stones can differ a lot. Thus, natural stones are not regulated in terms of porosity and movement.

Sandstone and limestone will be porous, granite and marble will be quite dense, slate could warp.

Adhesive may shadow through light coloured tiles

Some light-coloured natural stones require special care when fixing them.

Stains and different shades are frequent phenomenons that appear when fixing light-coloured natural stones (especially limestone/marble tiles). This can result from a bad transfer of the tile adhesive between the substrate and the natural stone. As well, if a grey adhesive is used, this can make the tile appear darker in shade once installed. (Alkalis contained in the cementitious adhesive can create a natural chemical reaction)

A spot-fixed method of application should not be used by tilers as it can result in shadows being seen from the tile face where the adhesive is in contact and it also increases the likelihood of pointload breakage.

 

 

Tiles may be susceptible to scratching

 Same tile grouts can scratch soft glazed tiles (such as hand-made tiles) and the surface of soft stone (such as marble).

Solution

Substrate preparation

Substrate should be dry and free from dust or any traces of old materials that could impede a good adhesion with the stones. In case of tiling over existing tiles or coating, ch e c k t h e adherence and repair the hollow areas or replace debonded tiles. In case of very porous substrate (a water drop absorbed in less than a minute) or very smooth surface, apply the primer weber.col prime using a brush or a roll.

Method of application

Tile adhesive

Apply a white adhesive weber.col flex, weber.col max, weber.col F1 or weber.col fast using a suitable notched trowel, adapted to the size of the stones and the flatness of the substrate.

For large size stones and on substrates presenting defects of flatness, use the back-buttering method (tile adhesive on the substrate and on the back of the stone).

Exert a strong pressure on the stones or use a rubber hammer to remove air and ensure a good transfer.

During application, carefully eliminate all traces of adhesive on the face of the stones with a wet sponge.

Stone grouting

Before grouting, wait at least 3 hours after application of webercol fast or webercol F1 (fast-setting adhesives) or at least 24 hours when using a normal setting adhesive. We recommend weberjoint perfect or weberjoint deco, at a width between 1,5 and 20 mm. The fineness of the grout particles reduces the risk of surface scratching the tile.weberjoint perfect is the right product to grout polished marble and any tiles with a soft surface. 

 

 

 

 

Solution with the following weber products

Solution

webercol max

Premium quality latex modified extra white cementitious tile adhesive

webercol F1

Fast-setting high performance tile adhesive with low dust technology

webercol flex

Two components high performance cementitious flexible tile adhesive (latex modified)

webercol fast

Fast-setting high performance tile adhesive with low dust technology

Solution

weberjoint perfect

High performance, Low Stain, cementitious tile grout with Hydro Repell and Mould Stop technologies

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