Insulation that you SHOULD NOT Fire stop Make sure your firestop installers are aware of the difference in insulation. They are NOT the same!
This is a cast iron pipe insulated with fiberglass insulation. The mason grouted back to the pipe insulation so there was no annular space in which to install the firestop. The firestop installers knew the inspector would notice it was missing, so they effectively "painted" sealant around the penetration. If there is a fire, the intumescent material will expand in the area of least resistance, which means it will expand away from the wall. Nothing will prevent the fire and smoke from coming through the rated wall prematurely. You will encounter similar issues any time the opening through the rated assembly is to small to accommodate both the insulation and the required firestop. This can happen when a sleeve is sized only large enough to accommodate the pipe and the required insulation, but not enough annular space in which to install the intumescent firestop sealant. This same issue can arise on a gypsum wall when holes are undersized. If you have these issues on your project, there are two solutions we can suggest.
This is an insulated pipe with a pipe saddle that is intended to prevent the insulation from being crushed by the hanger because it disperses the pressure caused by the weight of the pipe and its contents. The problem, in this case, is that the saddle is penetrating the rated wall; so if there were a fire, the intumescent firestop would not be able to adequately compress the fiberglass insulation against the pipe because the saddle is between the insulation and the firestop. If you see this problem on your project, just have the saddle relocated. In this condition however its not quite that simple. The pipe is going through a shaft, so remediation is going to be either incomplete or complex and expensive. This is why a pre-construction meeting from HLS can be a huge benefit to your project because we can outline all the problems we typically see on projects and help your construction team avoid them.
This is AB/PVC insulation, acrylonitrile butadiene/polyvinyl chloride. It is a flexible foam insulation often called rubber. It has a flat black finish and is rather soft with a smooth textured finish. You CAN firestop to this material with an intumescent firestop. Make sure your UL detail lists AB/PVC as the insulation type and pay attention to the insulation thickness because that may change the firestop requirements. This is typically listed either in line three or line four of your UL detail. If your firestop submittals only allow for 3/4" insulation but the installation is using 1-1/2" the firestop requirements may be different. Double check the details to make sure your project is not being compromised.
This is Polyethylene insulation. When new, it has a shiny finish and it has the same texture as a lemon. So, it looks and feels different from AB/PVC if you look at them. The big difference is that this insulation is in the polyolefin family of plastics, so it will melt at temperatures under 200F. This makes it very difficult to firestop properly, because most intumescent firestop materials need temperatures between 300F and 600F before they start to expand. When testing for a UL Listed system the temperature inside the test furnace is at 1000F after only 5 minutes. Additionally,, it is unlikely that your firestop submittals will have a listed detail that will allow THIS material. Make sure your insulators understand the difference so you are not exposed to this liability. If you see this running through a rated assembly, make someone take it out and replace it with an appropriate material.
This type of insulation has three problems that cause complications.
- A low melting point (around 400 F)
- The insulation is thick and leaves a large gap once it has melted
- The various jackets that encapsulate and protect the insulation from damage may pose the same problems the saddle caused with the fiberglass insulation noted earlier
These are the various types of covers that can be found on this type of insulation. The heavier shields will obviously cause more of a problem for the intumescent firestop.
So, if this insulation happens to penetrate a rated wall, please be certain it is removed and replaced with an appropriate material. This needs to be done at least in the section that encroaches on a rated assembly.