A high-performance commercial roofing system is complex, so knowing which products to use and which to pass on can be confusing for the average consumer. We’re here to help! Read on to learn more about fastener pullouts, and why they provide critical information on the proper design of your roofing system.
Fastener pullout resistance is a critical part of a roof system’s design process. Depending on the fastener type, deck material and deck condition, pullout values can be unpredictable.
Fastener manufacturers often provide pullout values for their products when they are to be used in reliable substrates such as new steel or wood decks. However, other deck types can vary depending on their quality and age. In these cases, the manufacturer will require field pull tests be performed to determine the deck’s ability to “hold” a fastener when it is subjected to negative wind uplift pressures. Deck types that require field pull tests include:
- Lightweight insulating concrete
- Cementitious wood fiber (tectum)
- Old structural concrete (rarely)
- Steel or wood decks if they are in questionable condition
When your project involves one of these deck types, the recommended procedure to assure your roof is designed properly is as follows:
- Determine the scope of work best suited for the project
- Work with your commercial roofing manufacturer to coordinate the pullout tests on site
- Determine which fastener type should be used for the project. Once pull tests are performed, work with your manufacturer to perform wind uplift calculations and determine the required fastening patterns to be used on the base sheet or insulation board.
Completing this process assures that your roof system is designed to resist the wind uplift pressures it may experience. Have more questions about fastener pullouts or other products? Contact us today to learn more.