What is an Adhesion Test?
If you have ever questioned whether silicone can be applied on your roof, a simple adhesion test can help you determine whether it’s the right choice. We answer the question, “What is an adhesion test?” in this blog and let you know how to do one. Additionally, there is a helpful how-to video in paragraph 5!
An adhesion test measures the adhesive characteristics of a product by measuring the amount of force it takes to separate that product from a test surface. For our industry, this test determines whether silicone will properly adhere to a roof substrate. Progressive Materials’ TJ Flick said the D903 adhesion test is the American Society for Testing and Materials’ standard test for roof coating adhesion. PM uses D903 because it is a part of the wider D6694 umbrella tests for silicone roof coatings. “We are required to pass D903 to say our coatings adhere to the standard D6694 tests,” TJ said.
Testing adhesion is crucial because PM’s top-quality silicone cannot offer its waterproofing capabilities and other benefits if it doesn’t stick to the roof. In rare occurrences, moisture under the roof substrate or other underlying issues can cause an adhesion failure. The D903 test can help identify these failures prior to coating. This will save you lots of time, money, and hassle if the roof is, for some reason, unable to be coated.
*Please note that when silicone won’t stick to a roof after an initial adhesion test, this doesn’t necessarily mean that coating will never stick. Sometimes a more intentional cleaning, primer, or removal of problem areas can prepare an area for coating without much effort or additional cost.
Testing Step by Step
To see a step-by-step video detailing the right way to do an adhesion test, click here. Otherwise, you can follow these simple seven steps:
- Thoroughly clean the surface where the test is going down with a wet rag. Make sure the surface is completely dry after cleaning before applying any silicone. Silicone will not adhere to anything if water is present.
- Use a brush to apply a thin layer of silicone to the area.
- Place one end of the pull test strip fabric into the silicone.
- Use brush to apply another top layer of silicone to the fabric.
- Dab a small amount of silicone to the un-coated side of the fabric.
- Let the test cure for at least 24 hours.
- Pull up on the uncoated fabric. You have good adhesion if the fabric is hard to pull off and there is silicone left on the substrate after it’s pulled. If the fabric pulls off with all of the silicone, you have poor adhesion. You need to either try a primer, make sure the surface was clean and dry, or look for underlying issues (moisture under the substrate, etc.)
An adhesion test will show whether your roof is ready for silicone or if other steps must be taken. This test is simple and easy to do, and most of all it’s free! If you are a PM Silicone customer, you can order a free adhesion test by emailing your Regional Manager here. If you are not yet a PM Silicone customer, you can learn more about becoming certified with us here.
Thanks for reading.