How to Use PolyFlash 1C Mastic

In this video, I wanna show you how to properly use PolyFlash 1C. Let’s get into it.

Product Description

PolyFlash 1C is a new material that we’ve really grown fond of. When it dries, it dries into a super elastic and hard material that can be used to flash and protect vulnerable areas, as well as difficult to flash areas. We’re gonna be applying it with a two or three-inch brush. One of your cheap ones from your local hardware store will do. And we’re gonna be reinforcing it with a polyester fabric. These come in either four, six or 36-inch rolls. In these videos, we’re gonna be using a four-inch roll around our details. We’re gonna be using it around our scuppers and any other vulnerable area that’s hard to flash. Let’s get into it.

Setup: Cut Polyester Mesh

PolyFlash 1C is a great solution for both areas that you really wanna make sure are bulletproof, as well as uniquely shaped flashings or penetrations on the roof. I’ve nailed down a random piece of metal on here. This is obviously not a real flashing that gets installed. However, I just wanted to show you that if you had a piece of L metal, we do have 90 degree L metals that are installed on flat roofs from time to time, and when they’ll structurally retrofit like a parapet wall, they’ll put angle iron all around a parapet wall. And we had issues. So we don’t like pitch pockets necessarily ’cause pitch pockets require maintenance.

PolyFlash 1C is a great solution. It’s warranted for up to 20 years and we found it to work very well, especially when it’s coupled with polyester fabric.

So the first thing we wanna do is really just cut out some polyester in preparation, scissors in our opinion works best. You wanna just reinforce that, you know, three, four inches on the top, three, four inches on the bottom, and you wanna do that for all three, four sides.

Now in corners, what we like to do is cut it at a 45-degree angle. That way we’ll have a proper overlap and protect that corner, so we’ll cut something like this out. Install this on this side and flap it around here, and we’ll do the same thing on this side.

Install First Layer of Mastic

So we’ve got our fabric ready to go. I’m gonna remove it. We’re gonna apply our first layer of PolyFlash, then install our polyester. You don’t wanna go on too thick, nor too light. You just wanna get a nice solid bed. Fill in any cracks and crevices. (Watch the above video at 2:19 to see how we spread on the Polyflash 1C mastic with a small brush.)

Place Polyester Mesh Pieces On Top

Once you have applied the mastic, place polyester fabric around the flashing. Make sure it embeds well into the wet mastic.

Second Layer of Mastic

You can see here we applied our first layer of PolyFlash 1C, embedded our polyester. Now, we’re going over with another light layer. You wanna make sure that the polyester is fully embedded and you’re not able to see much of that fabric anymore.