We have blogged about plastic sprinkler pipes in the past but it’s so easy to get it wrong, that it warrants more information. As always, we have a story for you, but before we get to the story however please know that despite the fact that we are mentioning two manufacturers in the story, we are NOT saying one is better than the other or showing favorites in any way. These are just the facts of the story as it played out in the field for us and could for you as well.
I was doing special inspection on a wood framed project where the installer was using STI’s WF300. This is a great material for wood framed projects. It’s cost effective and relatively versatile in wood framed construction. We had our submittals showing the listed details for each application they were using in the field. Towards the end of the project the contractor had the laborers make a supply run to finish up the final touches on the firestop. This is where our problem began.
After being in the industry for 20 years, a slight change in that iron oxide red causes one to take a closer look. The plastic sprinkler pipes came through a rated assembly and was firestopped like the other penetrations, but there was a slight difference in the material they used. Just barely enough to warrant a closer look, but just enough to see clearly, they used something different. Further discussion made the problem clear and rather serious.
Allow me to change gears for a moment and then we will bring these two discussions full circle.
CPVC pipes such as Flowguard, BlazeMaster, Corzan and TempRite are developed by Lubrizol. They have two great websites that you should keep handy if you work with projects that use plastic sprinkler pipes or CPVC.
This first one lists materials that have been tested and found to be compatible with these types of plastics.
This next one lists materials that are found to be incompatible. There are a handful of firestop products on this list. One of them is 3M’s CP25WB. Again, this is not a bad product, it is just not the appropriate material in this scenario and there are plenty of other materials on the list, so 3M is not alone. The problem is that the chemical compatibility can cause splits or holes in the plastic pipes. If the sprinkler pipes don’t start to leak before the sprinklers are needed, the change in pressure when the sprinklers engage will certainly test any system and one with small holes could impact water pressure and prevent sprinkler systems from performing as designed.
Here is another blog post on this topic in case you would like additional information.
This news article is just one of several that touch on the topic of compatibility issues.
So now that you have a little more background let’s get back to the story we started, back to our jobsite. The contractor sent a laborer to a local shop to get the firestop material they needed to finish the job. Certainly, on the shelf there was CP25WB and IC15WB. CP is red and IC is yellow. They knew that if they showed up on site installing yellow firestop that the inspector (aka me) would ask them for new firestop submittals for this new and different material, so they went with what seemed like the easy route.
When we returned for the inspection and noticed a slight difference in the color and started asking questions the installers brought the tube of the material they had used. They used CP on the CPVC pipes and as you can see from the links we shared; this creates a problem. Now that the materials have made contact the compatibility issue is present and you can’t just remove the sealant and replace it with the right red stuff or even the yellow stuff. You have to replace that section of pipe. If you don’t believe me, check with the various manufacturers or even your own corporate legal or risk management team.
It is not clear what this contractor chose to do, but after being informed of the issue and the potential severity we hope they chose to do the right thing.