Common doubts in Tiling

1. What tile adhesive shall be used on waterproofing coating? All adhesives should work. Even on polyurethane coating?

This doubt is very simple, but the answer is in chemistry of the product. All waterproofing coatings works for one goal and that is waterproofing the surface but chemically they are/may be different. For examples, Acrylic, cementitious acrylic, SBR based, Integral based, Crystalline based – these are good compatible with cementitious tile adhesive. Some type of waterproofing membrane like, polyurea, polyurethane, urethane is very different from the previous ones. These are made up of very close linked polymer structure, hence they form vert tight surface which will not allow subsequent material to bond by mechanically and even not by chemically. So, we have 2 options, first to ask the manufacturer that which adhesive is compatible and the second is to conduct the Pull-Off test at site level and take a joint decision along with client.

2. Vitrified tiles installed using Pre-mixed adhesive over the waterproofing coating is failed. Then, how can you say tile adhesive will work in this case?

Before we get in the answer, first let us understand how Pre-mixed adhesive and adhesive works differently.

Pre-mixed adhesive means formulated powder mixed with formulated liquid, supplied in air tight product. When you apply this adhesive, it starts de-hydration, liquid part evaporates, material get hard as tile bed bonding with the tile bottom and the surface. Tiles adhesive are supplied in the powder form, needs to mix with water and then applied. Polymer/chemical will hold the water, chemical utilizes while reaction and forms hard tile bed bonding between the tile bottom and the surface.

In this case, client used Premixed adhesive to install the vitrified tile which are impermeable, over the waterproofing coating which is also impermeable, then where is the way to liquid to evaporate? Adhesive remains wet, does not dry almost same as the air-tight bag. So, it will not get hard, not create the bond with tile or with the surface. In case if client use tile adhesive, tile adhesive does not need space to evaporate the water, it will use the water in chemical reaction, dries, get hard, achieve good bond with tile and surface.

3. Why we cannot use any primer / sealer for any toping material, as all primer and sealer will seal the porosity of the surface and provide the clean surface?

Primer and sealer are not same by function and by the chemistry. Primers, seals the surface, supress the fine dust (up to certain limit), bonds to the surface chemical/mechanically, provides chemically compatible surface for toping material. Whereas sealers, seals the surface, provides different look to the surface, provides breathability to the surface (some sealers only) and in most cases they do not gives compatible surface to the other toping materials.

Manufacturer designs the chemistry of the primer according the system. So, it is not good for client or to an applicator to re-design the system and test.

4. Moisture testing is necessary for the old and visible dry floors/walls?

There are 2 types of moisture in the structure. Surface moisture and the rising moisture. Moisture which is on the surface is surface moisture. Moisture in the matrix of the substrate but may/may not be on surface is supressed moisture and this may rise to the surface anytime, so it is called as rising moisture. Sometimes moisture may rise to the surface from the water sources like, pond, garden, river, water pipe leakage, etc., hence this is also called as rising moisture.

Surface moisture and moisture from the water pipe line leakage may be at any floor level of the structure. Whereas, rising moisture will be at the floor which is next to the soil or below soil level.

Considering the both situation, it is always suggested to the moisture test at least by plastic sheet method Or simple apply (DPM) Damp Proof Membrane.

For more accuracy, you can use electronic moisture testing instruments for surface moisture test and deep moisture test. For more details on moisture testing, refer: https://annayyachandrashekar.blogspot.com/2017/09/moisture-testing.html

5. Client and applicator says there is problem in the product. Applicator says, he is using our product and similar other’s product since many years and not seen this type of problem.

Whenever the problem rises at site level, it is obvious that everyone put blame on the product sometimes the sales officers of the manufacturer also. Here, everyone should know that all manufacturer has some set of rules to be followed before production and the stores department releases the product to the market. Once the technical team and R&D, finalize the product, production department produces the product and pack it. Technical team, randomly pick the packed product and conduct the testing. After passing all the test, product will be approved to handover to the stores department. Products will be manufactured in tons together in batch wise. These products will be dispatched to the end users as per request.

Let us assume, that there is a complaint in the product, then this should be reported from all the places where product has been sent. How comes, only one site or two sites will have the problem?

Other than this, it is necessary to observe the site condition and the site work procedure where there are multiple peoples will be working with their own set of rules and knowledge under different site condition.

6. Mesh Backed Stone / tile and Mosaics, de-bonded. Why?

If the following points are not observed, followed, then the failure is guaranteed. 

• All mesh/backing must be well adhered to the tiles, Mosaics with any form of mesh backing, and stone tiles which are resin mesh backed are not suitable for external wall tiling.

• At least 75% of the stone tile rear face must be exposed and fixed with tile adhesive – otherwise the tiles must be mechanically fixed. At least 75% of the mosaic tessera rear faces must be exposed and fixed with tile adhesive, the backing mesh must not deteriorate in service, otherwise mosaic tiles cannot be used.

• The mesh/backing on mosaics for wet/external areas must be water-resistant and the mesh glue should show no loss of adhesion with prolonged immersion.

(as per BS 5385 and The Stone Federation guidance - Appendix.

For still more problems before application, while application and after application, please refer to:

https://annayyachandrashekar.blogspot.com/2018/03/protect-products-from-nature-so-that.html

https://annayyachandrashekar.blogspot.com/2018/11/problems-and-solution-in-resin-flooring.html

As per the time line, we try to keep this data updated.