Thanks for the great response on the last post related to patching rated walls. There is a lot more I want to share with you in the future but I have to find time to create the content. I heard back from so many of you that you liked the post I thought I would at least share some more information that is already created so you can take it a step further.
Three key reasons the California patch will fail in a fire test scenario:
- It will fail at the hose stream test. For more information on this, check out this series we did a while back on Hose Stream and imagine that patch, or any patch you accept being able to pass the hose stream test as it is described in these posts from 2016. https://halpertlifesafety.com/firestop-inspection-f-rating-hose-stream/
- It will fail when you try to achieve the T rating- which is required of all rated walls and floors. There is a bit of information in this article here.
- As the drywall patch (or GOD FORBID drywall tape and mud excuse for a patch) heats up in a fire it will shrink. As the existing wall dries up it shrinks as well. When this happens the gap between the existing wall and the patch material grows. This makes it easier for the patch to dislodge during the hose stream test and this gap will allow hot gasses through and that is how the T rating segment of the test will fail.
So, the next time you see a patch in a rated wall, please take a second look to ensure it is not creating a liability for your project and the community of people who will live work and play in the building when you are gone.
As always, thanks for taking the time to learn more about the industry I love. If we can help you on any project you are working on, don’t hesitate to reach out to us.