10/22/2026
Ever wonder what a commercial roof drain looks like from underneath?
This is a retrofit roof drain, and it’s often used when replacing an existing commercial roofing system.
Instead of tearing out the original drain and replacing the plumbing, a retrofit drain fits inside the existing drain pipe and uses a watertight seal to prevent leaks.
Why use one? It can save time, reduce installation costs, and eliminate the need to disturb plumbing or interior finishes below the roof.
But here’s the catch: A retrofit drain is only as good as its installation. Proper sizing, sealing, and connection to the new roofing membrane are critical.
At Southern Roofing Co., we know that some of the most important details of a commercial roof are the ones you never see.