regndränningstest

Regndränningstest, or rain penetration test, is a testing method used to evaluate how well a material, joint, or assembly resists water intrusion when exposed to simulated rainfall. The test is applied to components such as building envelopes, coatings, membranes, seals, and textiles to assess their waterproofing performance and to support design decisions, quality control, and regulatory compliance.

In a typical regndränningstest, a specimen is positioned at a realistic angle and exposed to controlled rainfall conditions, often using a rainfall simulator or calibrated spray system. Conditions may include adjustable rainfall intensity, duration, and sometimes wind-like air movement to replicate rain-driven exposure. Water ingress is measured by observing leakage through joints or surfaces, collecting and quantifying water that penetrates the specimen, or detecting moisture with sensors or surface staining. Results are commonly expressed as leakage rate, maximum rainfall intensity that does not cause leakage, or a pass/fail classification based on predefined criteria.

The test is employed in various industries, including construction, textiles, and product certification. It helps verify that walls, windows, cladding, membranes, or weatherproof coatings meet performance expectations under rain exposure. Standards and protocols for regndränningstest exist at national and international levels, and may be issued as part of ISO, European EN, or regional codes, as well as by industry associations. Because rainfall patterns, wind, temperature, and aging affect real-world performance, test results are typically complemented by field data and durability assessments.

Limitations include differences between laboratory conditions and real weather, sample preparation effects, and the challenge of simulating long-term exposure. Nevertheless, regndränningstest provides a controlled, repeatable measure of resistance to water penetration.