“Layton Consulting Fenestration Nerds” By Anton Van Dyk: Field Water Testing of Windows. History, Purpose and Your Responsibility.
Field water testing of windows is not a new thing. The first time I was exposed to this was back in the late 90s when BC was in the middle of a Leaky Condo Crisis. Water testing back then was used on a lot of existing windows installed in buildings that struggled to manage water ingress. The test was done in a way that demonstrated if a product "measured up" to expectations and to determine if it could be re-used during a leaky condo renovation.
Fast-forward a bit, and this testing became a method for third-party design authorities to verify if a product, after installation, would meet the project requirements, as field water testing not only tested the product but also its integration with the building envelope.
It's important to understand that field testing of windows and doors is not a code-required expectation. For code compliance, all you need as a manufacturer is proof of NAFS Lab Testing. For the watertightness of an installed product, it is left up to the design professional to decide what they need to see in order to approve the final product. In most cases, these professionals are known as Building Envelope Consultants.
So, field water testing is most often required when specified on a project by the design team. This then often becomes a contractual obligation of the window/door manufacturer and installer to meet the specified test pressure. This obligation to meet this expectation often comes with consequences when the product and/or the installation of the product fails the test in the field. These consequences are often listed in the specifications, so it is important for sales/estimating teams to be able to understand the costs related to these consequences.
So, if you have never experienced this process before, you might be wondering where to look for the expectations. In the window specification section, you will often find the specified test pressure, which may or may not be code minimum pressure, so don't assume. If the pressure appears abnormally high or low, it is always best to clarify the intent as, in some cases, specifications are not always updated for a specific project (we call these "cut and paste" specs). The second thing to look for is a reference to AST E1105. This is the testing standard that lays out how a window can be tested in the field.
As there is a North American accepted standard for this test, it is important to understand what is in the standard and how it is to be used. I set both expectations for the person performing the test as well as for the manufacturer. A few key items that are in the standard that are often overlooked. These are:
The definition of a failure. This is defined as "water beyond the innermost plane of the window." This is critical and not subjective. Water contained in the window that does not spill over to impact the interior finishes is not considered a failure. This is because most windows manage water and do not keep water out at the outer face. When true rain-screen principles are applied, this definition makes perfect sense.
Calibration of testing equipment. Field testing needs to be held to the same standard as a lab test. The purpose of field testing is to verify that the lab results can be achieved in the field, so properly calibrated equipment is vital especially the rain rack. This device is designed to deliver a specific volume of water over a specific area, and field test equipment falls out of calibration over time.
Cycle testing vs. Static testing. There are two methods for testing: four 5-minute cycle tests with 1-minute no-pressure intervals or a single 15-minute static pressure test. It is important to ensure that the field-testing method chosen matches the method you used in the lab. Personally, I don't feel static testing is appropriate for windows that utilize rainscreen principle, as these windows are designed to manage water as opposed to a face-sealed system.
These are some basic items that are listed in the standard and why it is important to understand how to use the standard. There are a few other items that are a bit more subjective, and I have recommended window manufacturers list them as a contractual obligation to protect themselves. These are:
Environmental conditions during a test. As lab testing is done indoors at close to room temperature, gasket effectiveness for water sealing has a more effective performance outcome than when colder. So, when environmental conditions in the field are different from the lab conditions, this needs to be taken into consideration. Testing in the winter and testing before heat is applied inside a building can produce different results. Similar to how a gas pump is calibrated, you will see the temperature at which it is calibrated as the volume of gas changes based on the temperature.
Site conditions and qualify of installation. As field testing tests both the product and its integration with the envelope, we cannot ignore that a window installed out of plumb, level or square will result in the window not sealing as intended, and it may not perform to the specified pressures. It is recommended that a manufacturer inspects their windows for quality of installation prior to a test and approves the window for testing. If the window is out of plumb, level or square, then the manufacturer needs to inform that corrective measures need to be taken prior to testing and state that the window is not installed as per the manufacturer's instructions. It is also important to clear any debris away from the drainage path.
Testing Qualifications. A testing agency is not obligated to have certified and trained personnel perform testing. Most often, the people performing the testing are trained by other peers in their office. Due to this, testing variables may occur. Therefore, it is critical that the manufacturer knows and understands the details and expectations of a test and how to perform it correctly.
At the end of the day, third-party testing of windows is only growing, and window manufacturers who are supplying windows into markets where this testing occurs need to invest time into understanding how to use the ASTM E1105 standard and hold those accountable to ensure it is performed correctly.
Coming Fall 2024, I will be hosting a new workshop geared towards training manufactures/installers on how to interpret and apply the regulations listed in the ASTM E1105 standard. I was trained to do this test over 25 years ago, and not much has changed. Feel free to message me if you are interested and I will contact you.