Technical - TILE ADHESIVE AS PER IS 15477 : 2004 standard

IS 15477 – Explains the material which can be called as adhesive and can be used for the installation of tiles / stones. It explains the parameters of Tensile strength and shear adhesion strength including the testing method of open time, adjustable time, rheology test, tensile strength and shear adhesion strength. Other than this standard, the standards like ANSI 118, BS 5980 (Almost similar to IS 15477), IS 4832 and BS EN 12004 (Almost similar to ISO 13007).

Below are few important points to be considered:

Technical - TILE ADHESIVE AS PER BS EN 12004 STANDARD

This presentation briefly explains about the requirement to be fulfilled by the materials to be called as adhesive which can be used for the installation of tile / stone.

Watch the below video for details:

Technical - Conclusion of Tile adhesive as per IS 15477 - EN 12004_Presentation

Let see the type / patterns of failure:

1st & 2nd, if result is min not obtained, adhesive failed.
3rd, if result min not obtained, then repeat the test.
4th - if result is min not obtained, adhesive failed.
5th - if result is min not obtained, substrate is weak, hence treat the substrate.
6th - if result is min not obtained, Tile is weak, needs to get good tiles.

In all, if min result found, adhesive is passed.

The below presentation explains the conclusion of the tensile pull-out test parameters to be obtained in site when pull out test is conducted using 50mm dia tile / stone pieces…i.e. 0.133 Mpa as per IS 15477: 2004 and 0.5 Mpa as per BS EN 12004: 2007 on condition that the failure shall not be of pattern A.1, A.2 & A.4.

Watch this video for more details:

Technical - Pull-Off testing as per ASTM D 4541, D7234 & ISO 4624 Adhesive adhesion tester

This presentation explains about the Pull-Off adhesion test for testing the strength of the adhesive used for the installation of tile / stones. This test method covers a procedure for evaluating the pull-off strength (commonly referred to as adhesion) of a coating system from metal substrates.

The test determines either the greatest perpendicular force (in tension) that a surface area can bear before a plug of material is detached, or whether the surface remains intact at a prescribed force (pass/fail). Failure will occur along the weakest plane within the system comprised of the test fixture, adhesive, coating system, and substrate, and will be exposed by the fracture surface. This test method maximizes tensile stress as compared to the shear stress applied by other methods, such as scratch or knife adhesion, and results may not be comparable.

Watch the video for testing procedure:

Many thanks to google.com and doc88.com from where the details have been collected.

What does standard says – about how should be the bond strength?

1. For tile adhesive, as per Indian standard IS 15477 – 750N - 0.13 N/Sqmm. )old standard). As per new standard C1 - 0.5 MPa and C2 1 Mpa.
2. For tile adhesive, as per BS EN 12004 –C1 - 0.5 MPa and C2 1 MPa.
3. For tile adhesive, , Australian Standards 2358 "Adhesive for Ceramic Wall Tile" which fixes a minimum tensile bond strength of cement based adhesives after seven days.  This bond strength requirement is a minimum of 0.15 MPa (22 psi).
4. ASTM F 1147-05 – Adhesion to substrate shall be >20 MPa
5. CSA A23.1 gives a minimum bond strength for toppings of 1.0 MPa (145 psi)
6. Tensile adhesion strength as per Singapore HDB method shall be of - average strength  > 0.80 N/Sqmm and individual strength  > 0.60 N/Sqmm
7. BS EN 1015
8. The minimum expected bond strength is 0.5 MPa, in accordance with BS EN 14891 – Liquid-applied water impermeable products for use beneath ceramic tiling bonded with adhesives

ASTM D4541, “Pull-off Strength of Coatings Using Portable Adhesion Testers” - Different testers may yield different pull-off values

1. Annex A1: Fixed Alignment Type II (mechanical)
2. Annex A2: Self Aligning Type III (hydraulic)
3. Annex A3: Self Aligning Type IV (pneumatic)
4. Annex A4: Self Aligning Type V( hydraulic)
5. Annex A5: Self Aligning Type VI (hydraulic)

Do we need to test the bond strength?

1. Thicker material may give the value of cohesive strength (Inner-strength of a material) not the bond strength of material with the substrate.
2. May produce misleading pull-off values (false, high).
3. Scoring through material (down to the surface) and value may be of cohesive strength of surface.
4. Test specimen may get disturbed while fixing dolly OR at the time of fixing the machine attachments and reading may vary.
5. Force / load application in un-uniform way may vary the readings.
6. Since all surface are not homogeneous, reading will vary and the dolly shall be larger in size.
7. The readings may be of bond strength of surface not of the material.
8. In general, if the surface has high compressive strength will have low surface tensile strength… readings will be very low.
9. Readings will be of min value, but actual bond strength of material will remain unknow.
10. Pull-off strength / bond strength data is not typically a predictor of subsequent application performance.
11. No industry is having adhesion acceptance value.
12. Pull-off adhesion (resistance to perpendicular pull), requires specialized equipment and value cannot comparable, since testing mechanisms are different than the site level.

Scoring/cutting is recommended or not?

1. ASTM D7234 does not require cutting to the substrate in all cases. - "While scoring is recommended for coatings thinner than 0.5 mm (20 mils), the test may be performed without scoring, but the results should note this exception."

2. ASTM D7234 recognizes the risk of damage from cutting and specifically requires that scoring: "...minimizes heat generated and edge damage or microcracks to the coating and the concrete substrate."

3. ASTM D4541 - The standard contains several test methods (Type II, III, IV, V testers), and cutting is generally intended to isolate the test area from surrounding coating stresses. Hence, standard talk about : "if cutting is performed" or "score around the fixture," rather than an unconditional requirement.

4. ISO 4624:2023 states: "Cutting around the dolly is optional for films <150 μm and must be reported if performed."

The purpose of pull-off testing is to determine the weakest plane in the system. Excessive cutting may artificially weaken the test area by introducing heat, vibration, micro-cracking, or stress concentrations. ASTM D7234 acknowledges this risk by requiring scoring methods that minimize heat generation and substrate damage. Furthermore, ASTM D7234 permits testing without scoring, provided the deviation is reported. ISO 4624 also does not universally require cutting and permits testing without cutting under certain conditions. Therefore, cutting should be selected based on the coating type, thickness, and testing objective rather than applied indiscriminately.

"Pull-off testing was performed without perimeter cutting/scoring to avoid introducing potential edge damage or micro-cracking into the coating/substrate system."