Redefining moisture management: The SlopeShield Plus SA

By Emma Peterson.

Learn the science behind how SlopeShield Plus SA keeps moisture out of the building envelope.

For a new episode of Roofing Road Trips®, Chris Meyer of VaproShield stopped by The Coffee Shops™ and spoke to Karen Edwards about the issue of condensation in construction and how VaproShield addresses this problem — SlopeShield Plus Self Adhered (SA). This innovative product is a multipurpose membrane that is able to effectively mitigate moisture intrusion in the building envelope. It does this through a unique combination of being both an air barrier and permeable vapor retarder.  

Traditionally, it has been thought that just a vapor barrier would effectively manage the moisture in a building envelope, but this is not necessarily true. Chris explained, “There was an IIBEC article around moisture infiltration in mechanically attached roof systems that was talking about how wherever air moves, so does moisture. And air movement can move up to a hundred times more moisture than diffusion can.” So, while vapor barriers are effective at stopping moisture from entering via diffusion, there needs to be another component, an air barrier, to effectively manage moisture.  

And this is not just a concern in the construction process, as the air can continue to carry moisture into the roofing assembly even after the project is completed. Chris shared some of the ways this can happen, saying, “The most common scenario is the creation of a vacuum due to negative wind pressure coming across the roof on a daily basis, every minute, every hour. That vacuum draws that internal environment air up into your roof. When it hits cold surfaces, moisture starts to accumulate in that air, it condenses, now you have a problem.”  

But, because Slope Shield Plus SA is not just a vapor retarder but also an air barrier, it can effectively stop air circulation and mitigate this problem. Further, because it is a permeable vapor retarder, rather than a vapor barrier, it can actually release moisture that gets trapped. Chris explained, “Using a true vapor barrier often actually causes more problems than it solves. But SlopeShield has a breathability aspect that allows the system to adapt. So, while it blocks the majority of moisture from ever getting in there in the first place, it is also able to release any trapped moisture that somehow accumulates.”  

Read the transcript or Listen to the episode to learn more about SlopeShield Plus SA and how it is improving moisture management practices.