This question comes up A LOT in the snow guard world as many of our retro-fit installations use the Woodbinder Eclipse screw, face-fastened to fasten the snow guard onto the roof. The short answer is that if the snow guard is installed in accordance with our specifications then no, it will not cause leaks.
The Woodbinder Eclipse is a commercial grade roofing screw that is manufactured specifically for this type of work. The Woodbinder Eclipse is specifically designed as a fastener for exposed fastener metal panel roof and retro-fit installations. The Woodbinder Eclipse has a large head that covers and "encapsulates" the rubber grommet beneath providing a self-flashing, fully leak-proof seal. With the use of a proper sealant under the snow guard strap, the snow guard will be as water tight as the roof covering itself. In fact, we have many high-end projects located in some of the snowiest places in North America with thousands of snow guards attached using the Woodbinder Eclipse. We have never heard of an issue with our snow guards causing a leak.
Check out our retro-fit snow guard installation instructions and video. We're confident that our retro-fit snow guard installation method will provide secure, leak-proof attachment for the life of the roof.
We can provide them with all the information necessary to ensure that they install these snow guards correctly and in a fashion that is compatible with your specific roofing system.
For more information, please do not hesitate to contact us!