EN 1607 Thermal Insulation Products for Building Applications - Determination of Tensile Strength Perpendicular to Surfaces

The European standard "EN 1607 Thermal insulation products for building applications - Determination of surface tensile strength" describes the equipment and procedures required to determine the surface tensile strength of a product. These procedures apply to thermal insulation products.

For the purposes of this standard, the tensile strength perpendicular to the surfaces is the value obtained by dividing the maximum tensile force recorded perpendicular to the product surfaces during the tensile process by the cross-sectional area of ​​the test sample.

In principle, a test specimen is placed between two rigid plates or blocks, secured in a tensile testing machine, and pulled apart at a specified speed. The maximum tensile force is recorded, and the tensile strength of the test specimen is calculated.

The tensile testing machine used in these tests is capable of measuring force with an accuracy of plus or minus 1% and a constant crosshead speed of 10 mm/min, suitable for the relevant force and displacement range. Additionally, rigid plates or blocks with self-aligning connections are used to prevent uneven distribution of tensile stress during the test. Examples of suitable arrangements for bonding the test specimen are provided in the standard. The following adhesives are also used to bond the test specimen between the rigid plates or blocks during the tests:

• The adhesive must not strengthen or damage the surface layers of the product.
• Hot glues should be avoided if they damage the product.
• Any solvent used must be compatible with the product. Any testing equipment that provides at least the same results with the same accuracy can be used.

The thickness of the test specimens shall be equal to the thickness of the original product, including all external surfaces, finishes, and coatings. Test specimens shall be square prisms with the following recommended side dimensions: 50 mm x 50 mm, 100 mm x 100 mm, 150 mm x 150 mm, 200 mm x 200 mm, or 300 mm x 300 mm. The dimensions used shall be as specified in the relevant product standard. In the absence of a product standard or other European technical specification, the dimensions of the test specimens may be agreed upon between the parties. Linear dimensions shall be determined to an accuracy of plus or minus 0,5 percent in accordance with EN 12085.

The mechanical properties defined in EN 1607 are critical in assessing how insulation materials perform under stress in applications such as building envelopes, particularly when bonded to surfaces or used in composite systems. This standard applies to all factory-made thermal insulation products, including:

• Expanded polystyrene
• Extruded polystyrene
• Polyurethane foam
• Mineral wool
• Phenolic foam

The primary purpose of the test is to determine the mechanical integrity of insulation boards when forces act perpendicularly (i.e., at a 90-degree angle) to the primary surface. This is particularly important in applications where panels are bonded to surfaces or where wind suction or mechanical loads could cause such stress.

In general, these tests consist of the following steps:

• Sample preparation: The insulation product is cut into standard test samples, usually square or rectangular. This standard recommends a minimum sample size of 50 mm x 50 mm, although larger samples may be used.
• Bonding the loading plates: Metal plates are bonded to the top and bottom surfaces of the sample using a strong and tough adhesive that does not affect the performance of the sample.
• Tensile testing: The specimen is placed in a tensile testing machine. A uniaxial tensile load is applied perpendicular to the surfaces until the specimen ruptures (fractures).
• Results evaluation: The maximum force recorded before rupture is used to calculate the tensile strength and is expressed in kilopascals.

The results help manufacturers and engineers:

• Ensuring compliance with product standards (e.g. CE marking under the construction products regulation)
• Comparing different materials or suppliers
• Designing structural systems with adequate mechanical strength
• Predicting how materials behave over time under stress conditions

A higher tensile strength value indicates that the insulation material better resists separation or delamination, which is crucial for ensuring long-term performance in exterior thermal insulation composite systems and other similar applications.

The EN 1607 standard is important because it ensures that thermal insulation materials used in construction are mechanically sound, especially when subjected to tensile forces (tensile stress) perpendicular to their surfaces. The main reasons for this standard's importance are:

• Ensures the mechanical integrity of insulation materials: Insulation boards in buildings are often bonded to walls or other surfaces. If the insulation lacks sufficient tensile strength, it can delaminate, crack, or deteriorate over time due to mechanical stress (e.g., wind absorption, thermal expansion, or building movement). This standard tests whether the material can withstand these forces without breaking.
• This is critical for exterior thermal insulation composite systems: In these systems, insulation boards are glued or mechanically fastened to the facades. Low tensile strength can lead to system failure, water ingress, or insulation separation. This standard helps designers and contractors select materials with adequate performance for such demanding applications.
• Supports product certification and compliance: Manufacturers use this standard to demonstrate compliance with CE marking requirements under the Construction Products Directive (CPR). This is a mandatory test for insulation products often listed in European technical approvals.
• Enables quality control and material comparison: Regular testing against this standard helps manufacturers ensure consistent product quality. Designers and engineers can compare materials from different suppliers based on standardized performance data.
• Safety and long-term performance: Buildings are expected to perform safely and efficiently for decades. Insulation failure can lead to energy loss, water damage, mold growth, and higher maintenance costs. This standard helps reduce the risk of premature failure by verifying the insulation's durability under mechanical stress.

Consequently, the EN 1607 standard plays a vital role in assessing the durability and reliability of thermal insulation products in construction. Understanding and applying this standard helps select the right material for specific applications, particularly where mechanical stresses can affect performance.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, boasts a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with the standard "EN 1607 Thermal insulation products for building applications - Determination of perpendicular tensile strength of surfaces."