UNDERSTANDING ASTM E1105: A SIMPLIFIED GUIDE

Scope and Purpose

• The test determines whether an installed fenestration system meets the performance criteria specified in the contract documents or the product’s code-required certification label.
• It applies to complete assemblies and can also be used to evaluate joint interfaces between fenestration products and surrounding construction.
• Water penetration, as defined by this standard, occurs when water breaches the innermost vertical plane of the test specimen.
• This test does not provide insight into how a system might perform under real-world conditions, as it does not simulate natural rainfall or environmental exposure.

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Test Method Summary

1. Test Chamber Installation

• A sealed test chamber is attached to either the interior or exterior face of the specimen.
• Air is exhausted (for an interior-mounted chamber) → Reduces pressure inside the chamber, decreasing the pressure inside the specimen relative to the exterior air.
• Air is supplied (for an exterior-mounted chamber) → Increases pressure in the chamber, increasing the pressure outside the specimen relative to the interior air.
• The pressure difference is carefully monitored during the test.

2. Water Application

• A spray rack applies water at a minimum rate of 5.0 U.S. gal/ft²·h (3.4 L/m²·min).
• The spray rack must utilize a uniform grid of nozzles spaced according to the standard.
• Note: The water is not applied uniformly across the specimen; rather, the nozzles are uniformly spaced to ensure consistent coverage.
• Adding extra nozzles to the rack outside of the prescribed grid spacing (e.g. extra nozzles on the spray rack header) would violate compliance with ASTM E1105.

3. Pressure Application and Test Procedures

The specimen is subjected to one of two test methods:

(A) Uniform Static Pressure Test

• A static air pressure difference is applied and maintained for 15 continuous minutes, while water is continuously and simultaneously sprayed on the specimen via the uniform nozzle grid spray rack.

(B) Cyclic Static Pressure Test

• A static air pressure difference is applied for 5 minutes, followed by a 1-minute pressure release, while water is continuously and simultaneously sprayed on the specimen via the uniform nozzle grid spray rack throughout.
• This cycle is repeated for at least 4 total cycles (20 minutes of total pressurization), but a specifier may choose a 3-cycle (15-minute) sequence or more cycles if required.
• The purpose of the cyclic test is to introduce intermittent stress on the specimen and drainage/weep relief, which can better simulate some real-world pressure conditions contrasted with a constant, sustained, 15 minute static load.

4. Water Penetration Criteria

• Water penetration, according to this procedure, only occurs when liquid water appears beyond the innermost vertical plane of the test specimen.
• The mere appearance of water on frames, gaskets, glazing beads, or outboard components does not constitute a failure under ASTM E1105.
• If an owner or specifier wishes to define failure under a more stringent criterion (e.g., any visible water at all), this must be explicitly coordinated, contractually memorialized, and specified in the project documentation.
• Water contained within designed drainage paths (e.g., weep systems, flashing, gutters) is not considered failure under this standard.
• The mere appearance of water on frames, gaskets, glazing beads, or outboard components does not constitute a failure under ASTM E1105.

5. Post-Test Inspection

During the test, visible interior surfaces are inspected for the presence of water, and pressure differential and rate of water volume delivery are monitored. After the test, interior chambers (if present) are removed and the following additional inspection is conducted:

• Once the pressure and water spray are stopped, a final inspection is conducted to document any additional water penetration that may have occurred.
• Atmospheric conditions such as wind speed, temperature, and barometric pressure are recorded at the time of testing.

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Significance, Applications, and Limitations

Verification of Installed Performance

• ASTM E1105 is used to field-verify that an installed fenestration system meets the performance criteria specified in the contract or on its certification label.
• Unlike laboratory testing (e.g., ASTM E331), this test evaluates actual installation conditions, including perimeter sealant continuity, anchorage, and assembly tolerances.

Not a Diagnostic Test for Leakage Investigations

• While some consultants mistakenly use ASTM E1105 for forensic investigations, this test is not a useful tool for diagnosing water leakage in existing buildings.
• The test does not identify leakage sources—it only verifies whether an assembly passes or fails under controlled conditions.
• A failed test does not reveal the cause of the failure; additional investigative techniques (e.g., infrared thermography, tracer dyes, destructive testing) are required for proper diagnostics.

Non-Correlation to Natural Rainfall

• ASTM E1105 does not simulate real-world weather conditions.
• The spray rate is not equivalent to any specific rainfall amount or intensity.
• The test addendum (Appendix X1) explicitly states that correlating the test to natural rainfall is incorrect.
• Natural rain events involve complex wind-driven forces, droplet variations, and directional changes, none of which are replicated in this procedure.

Environmental Factors Affecting Results

• Wind gusts exceeding ±10% of the test pressure can interfere with results, and the test should be postponed under such conditions.
• Aging, installation quality, and handling damage may impact performance compared to laboratory test results.
• The test does not measure air infiltration, as isolating the fenestration assembly from intentional openings (e.g., weep holes) is impractical.

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Conclusion

ASTM E1105 is a field-based verification test designed to assess the water penetration resistance of installed fenestration systems. While it does not replicate natural rain conditions, it provides a repeatable and standardized method for evaluating performance against project-specified criteria. This test should be used for quality assurance and contract compliance, not for diagnosing leakage issues in existing buildings. Understanding the scope, intent, and limitations of ASTM E1105 is critical to its proper application in construction and forensic evaluations.

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