Project #167 | Rotted Roof Deck Renovation – Baltimore, MD

PROJECT: Residential Roof Deck with Posts – Baltimore, Maryland


This roof deck was originally ‘waterproofed’ with a membrane product, but really, the end result was not anything even close to water tight!

The previous installers did not take care of any of the important waterproofing details when the membrane was laid. Critical areas, like the posts for example, did not receive proper waterproofing techniques and it allowed moisture to make its way to the substrate.

Once water has found a way in, it will steadily encourage mold and wood rot that can spread quickly to result in a spongy, soft deck surface.


When the Duradek installers pulled off the railings and pulled up the old material, it was shocking to see how badly the deck substrate had actually become.

The wood rotted to the point of crumbling and the entire surface, as well as some minor joist sections, had to be replaced. The substrate was prepared with 3/4″ untreated T&G plywood to received the new Duradek Ultra Supreme Granite Chip vinyl. The vinyl was installed with Duradek’s recommended detailing techniques that properly waterproof the deck, and the existing railings were able to be re-installed.


PVC membranes are one of the most, possibly THE most effective single-application method of waterproofing a pedestrian roof deck…but it must be installed correctly to perform as intended. That is why Duradek vinyl membranes are only available through a select group of installers that have been trained in the intricate details of deck waterproofing.

View or download the .pdf version of Case History #167 for the complete case history with installer details and before and after pictures.