EN 15816 Polymer Modified Bituminous Thick Coatings for Waterproofing - Rain Resistance

A European standard, “EN 15816 Polymer-modified bituminous coatings for waterproofing - Rain resistance”, describes a procedure for determining the rain resistance of polymer-modified bituminous coatings for waterproofing purposes.

For the purposes of this standard, the terms and definitions given in EN 15814 apply. Rain resistance also refers to the resistance of polymer-modified bituminous coatings to the damaging effects of exposure to rain.

In principle, the test demonstrates the rain resistance of a thick, freshly applied polymer-modified bitumen coating. The time a coating can be considered rain resistant under construction conditions can vary significantly from the time determined in the laboratory. Therefore, the measured values ​​are primarily suitable for comparing the rain resistance of different products.

The equipment used in these tests includes:

• Sprinkler: Standard conical nozzle made of copper-zinc alloy, pipe thread conforming to ISO 228-1, 85 degree sprinkler cone, flow rate of 9 l/min at 3 bar working pressure, commercial pressure regulator with pressure gauge showing test pressure plus/minus 0,1 bar, sample holder to place the sample at a 45 degree angle to the sprinkler plane.
• Nozzle holder to place the nozzle: The nozzle should be placed so that the vertical distance between the nozzle and the center of the sample surface is 25 cm.
• Connection to water mains, hoses, connectors.
• Timer
• Samples: Concrete base with a smooth or ground surface of not less than compressive strength class C20/25 according to standard EN 206-1, a coating with an area of ​​approximately 150 mm x 150 mm can be applied.

At least two samples are required for testing. The samples should be approximately 150 mm x 150 mm in size. After coating, the samples should be stored in a normal climate of 23 degrees Celsius plus/minus 2 degrees Celsius and a relative humidity of 50 percent plus/minus 5 percent, in accordance with the ISO 554 standard, for a period specified by the manufacturer, but not exceeding 8 hours.

Tests should be conducted at 25°C plus/minus 5°C. Samples should be tested after conditioning. Before testing, the water pressure should be set to 2 bar plus/minus 0,1 bar with the water flowing. The water temperature is measured. Two samples are tested simultaneously in two test devices or immediately consecutively in the same test device. The samples are placed in a holder under running water, and a stopwatch is started. The test lasts 15 minutes. During the test, the color of the water flowing through the test samples is checked for discoloration. If necessary, the test is repeated using different samples.

Water flowing through the test samples must not change color during the test, and the coating must not deteriorate (e.g., surface erosion, water accumulation in the material). In the event of such deterioration, the test should be repeated on the remaining samples with a longer conditioning period until at least two samples pass the test. The test result should be the shortest conditioning period (0,5 hours) during which two samples show no color change. This is the time within which a freshly applied polymer-modified bitumen thick coating can be designated as rain-resistant as defined in this test specification. This period should not exceed 8 hours.

The EN 15816 standard is important for several reasons, particularly in the context of quality assurance of waterproofing materials such as bituminous, plastic, or rubber sheets used in construction. The main reasons for its importance are:

• Evaluates resistance to mechanical damage: This standard specifies a test method to determine the resistance of waterproofing membranes (such as bitumen sheets, plastic sheets, or synthetic membranes) to mechanical damage. This is crucial to ensuring the membranes remain intact throughout their installation and service life, particularly in areas subject to falling objects or foot traffic.
• Ensures surface quality: Provides a systematic method for assessing visible defects in waterproofing membranes (e.g., holes, cracks, bubbles, inclusions, discoloration). These defects can compromise the integrity and performance of waterproofing systems.
• Ensures long-term waterproofing performance: If a waterproofing membrane is easily damaged by impact, water can seep into the structure and cause costly damage. The EN 15816 standard helps prevent this by setting a benchmark for durability.
• Supports product comparison and quality control: Manufacturers use this standard to evaluate and compare the impact resistance of different materials. It also helps builders, engineers, and specifiers select the right product for specific applications (e.g., roofs, basements, tunnels).
• Mandatory for CE marking (under the CPR): This standard is part of the harmonized standards for flexible waterproofing boards under the Construction Products Directive (CPR). Products tested to this standard can be CE marked to demonstrate compliance with European Union safety and performance requirements.
• Helps prevent structural failures: By ensuring waterproofing materials are impact resistant, the standard helps prevent problems such as leaks, corrosion, mold and structural deterioration.
• Critical to product acceptance: Manufacturers, specifiers, and installers rely on EN 15816 to determine whether the delivered product meets visual quality criteria before assembly. This standard is often part of factory production control and incoming material inspection.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, has 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 to businesses in accordance with the EN 15816 standard for "Polymer-modified bituminous thick coatings for waterproofing - Rain resistance."