Laying tiles on epoxy glue: rules and choice of materials

Recommendation points

• Properties and scope of glue
• Basis preparation rules
• Preparation and features of using glue
• Technique for laying tiles on two-component adhesive

The properties of ordinary tile adhesive are not always sufficient to meet the operating conditions. From the review, you will learn which adhesives should be used for coatings that are operated under water or in an aggressive environment, and which rules should be followed when laying tiles..

Properties and scope of glue

The tile covering has only surface protective properties. The weak point of such a finish is the seams between the tiles, which eventually collapse under the influence of erosion and mechanical vibrations. At the same time, access to the adhesive seam is opened for moisture, due to which the peeling of the tile and the loss of waterproofing properties are inevitable.

Two-component epoxy tile adhesive has increased ductility, so the seams do not crack. High strength and resistance to aggressive chemicals ensure long-term operation even in very harsh conditions. In addition, the epoxy adhesive has increased adhesion, which reduces the effect of substrate defects on the final properties of the coating..

Epoxy tile adhesives are typically polyurethane based. The adhesive contains two components – a liquid hardener and a thixotropic paste. Thixotropy is the property that provides the composition with a high viscosity at rest, however, under mechanical action, the glue significantly liquefies. This improves the usability of the adhesive mixture and simplifies the alignment process..

Using epoxy tile adhesive, it is possible to simultaneously provide high waterproofing properties of the coating and its resistance to operation in aggressive environments. The direct purpose of such glue is for lining tanks with liquids and floors in rooms that are periodically exposed to strong moisture. In everyday life, epoxy tile adhesive is used in the construction of shower rooms, decoration of swimming pools and garage floors..

The high cost of two-component glue does not allow it to be used everywhere. It is often easier to apply a hydro-barrier to the substrate and use an adhesive mixture that is highly resistant to high humidity. However, if materials are used in the structure under the tiles for which the ingress of water is unacceptable, or the coating will be operated in constant contact with liquid, epoxy glue provides the first circuit of reliable waterproofing with high resistance to external influences.

Epoxy glue is suitable for gluing almost all types of tiles, including porcelain stoneware and mosaics, which Our site Soviets.RU has already described in detail. There are some peculiarities of working with large-format coatings, because the mixture must be prepared in separate portions and take into account its limited life time. Mixing a fresh composition with a previously prepared one, as is practiced when using dry mixtures, is strictly not allowed.

Basis preparation rules

Despite the fact that after curing the epoxy adhesive retains its plasticity, there are quite strict requirements for the preparation of the subfloor. They relate to leveling, density and strength, water absorption and cleanliness.

The preparation method should be chosen depending on the type of base:

• For cellular concrete, it is recommended to apply a layer of moisture-resistant plaster such as Ceresit CT 25 for seamless masonry or budget Polimin ШВ-1 on a cement-lime basis for fine-seam.
• The concrete surfaces of monolithic structures need to be invoiced before applying the preparatory layer. After making numerous notches with a chisel, the surface must be covered with polymer-cement plaster – Ceresit CT29 or a conventional cement-sand mixture according to GOST 57984-2017, followed by coating with a water repellent.
• Brick walls are prepared by plastering with a reinforcing mesh or by spraying without reinforcement. Standard mixes with added superplasticizer are suitable.
• The preparation of drywall consists in the correct cutting of the joints, gluing the reinforcing tape and applying frost-resistant tile adhesive with a layer of 5–10 mm. After drying, the surface must be thoroughly impregnated with acrylic primer for highly absorbent surfaces..

As you can see, one of the most important qualities of a rough surface is water resistance. Due to its high viscosity, adhesive for tiles on an epoxy basis is not able to penetrate deep into the pores of the material, the contact layer is just over a millimeter. Therefore, the surface must be solid, free of cracks and dense enough to support the pull-off load well. The increased humidity of the base, the presence of dust or dirt on it, reduce adhesion to almost zero. And although after laying on an uncleaned substrate, the impression of a durable and reliable coating is created, in extreme operating conditions, the tiles will peel off almost immediately..

Before using epoxy tile adhesive, read the preparation requirements of the manufacturer. They determine not only alignment tolerances, but also special preparation methods and compatible materials..

Preparation and features of using glue

Tile adhesive is supplied in a rigid plastic container in almost finished form, it is enough just to mix the base with the hardener using a construction mixer or a drill bit. However, the cooking process has a number of features. For example, it is highly recommended to pour the prepared portion of the mixture into a clean container and re-mix. This rule, which is considered common for all multicomponent mixtures, will avoid the formation of a poorly mixed mass that collects at the bottom and walls..

As already mentioned, it is categorically not allowed to mix compositions prepared at different times, this significantly reduces the life of the mixture. It, depending on the manufacturer and brand, can be 60–120 minutes, which is quite enough to use up the entire portion of glue. This allows you to mix the base with the hardener without dividing into portions, which means that the recommended ratio of ingredients is guaranteed to be met. If for some reason it is necessary to prepare small portions, it is recommended to use an electronic scale for dosing..

Any polyethylene-based container is suitable for re-mixing. After drying, the glue residues easily peel off the walls and bottom, so there will be no special problems with cleaning. However, you need to be careful in other aspects: removing dried glue residues from the floor and the tool will be a big problem, so you need to clean off the glue immediately and periodically wash the tool during operation.

Technique for laying tiles on two-component adhesive

Working with epoxy-based glue has only two nuances. Firstly, when laying the tiles, it is imperative to thoroughly clean the seams, preventing glue residues from hardening in them, which, after drying, will be extremely difficult to remove. Secondly, one should take into account the thixotropic properties of the mixture and understand that increased viscosity is not a sign of too fast curing. The settled and thickened glue only needs to be stirred intensively, after which it can be easily applied with a comb, by analogy with conventional mixtures. It is better to wait about a minute before placing the tiles on the glue to increase the viscosity of the mixture. For leveling, it is enough to only slightly move the tile: adjusting the intensity of the mechanical effect, you can achieve different degrees of liquefaction. It is not recommended to plant the tiles with blows from a mallet..

Tiles can be tiled 24 hours after laying, the coating can take on the operational load after 7 days. As a joint filler (fugue), you can use the glue on which the tiles are laid. The disadvantage of this grout is the limited range of colors: most manufacturers offer up to a dozen universal shades, which is not enough to create a coating with really high aesthetic qualities. The special epoxy fugue has the same base as the glue, but differs in the use of higher quality pigments and a finely dispersed filler. This grout will provide a high variety of shades and their saturation..