A Trick to Avoid Outgassing Bubbles on Concrete Floors

Are porcupine rollers the solution for outgassing bubbles on concrete floors? So you’re coating a concrete floor in an area that isn’t climate controlled and you keep getting outgassing bubbles. You’ve tried to pop them with a porcupine roller, but they keep showing up. As the coating sets up, you’re afraid to walk back onto it to pop those last ones. You know it. The bubbles know it. They have won. And they are laughing at you with their tiny bubble laughs that only they can hear. So what’s a painter to do?

Interesting fact: Porcupines can have up to 30,000 quills.

So what’s the solution to the outgassing bubble problem? In my opinion, the solution isn’t figuring out how to pop those pesky bubbles with a porcupine roller. The solution is figuring out how to make sure that they never appear in the first place. Concrete is like a sponge. It can absorb air and also release the same air. When concrete is getting hotter, the air inside the concrete expands and needs to escape. When it does, it pushes up through the coating that you just applied. When this happens, the outgassing war begins, and you’re probably going to lose. This will be especially noticeable on the first coat, but it may also occur on the second coat if you have pinholes or thin spots in the primer. If you want to avoid outgassing bubbles when coating a concrete floor, try coating the floor in the evening when the concrete is getting cooler. As the concrete cools, air will be pulling into the concrete. If you do it this way, you’ll get deeper primer penetration into the concrete and it’s far less likely that you’ll see outgassing bubbles.