Best Approach for Roofing Over a Concrete Deck? Dealing with Moisture Concerns

Hi everyone,

I’m working on a project involving a concrete roof deck, and I’m running into some concerns regarding moisture control and insulation. The deck itself is solid, but there’s been a history of moisture issues in the building, and I want to make sure I approach this correctly to avoid future problems.

Here’s the situation: The previous roofing system had signs of trapped moisture, and while the interior damage wasn’t severe, it’s clear that something wasn’t working as intended. I’m considering my options when it comes to vapor barriers, insulation placement, and the best type of roofing system for this type of structure. I know that concrete holds moisture differently than other substrates, so I want to be sure I’m not creating a situation where condensation or thermal bridging becomes a bigger issue down the line.

Has anyone here worked with roofing over concrete decks before? What’s the best way to prevent long-term moisture problems? Should I be looking at specific types of insulation or vapor barriers to handle this better? Also, I’ve heard mixed opinions about fully adhered vs. mechanically fastened systems for concrete—any recommendations on what works best?