Fire Caulk, Putty and Sleeves - The Very Basics

I in no way would classify myself as a fire stop expert, not even a novice, but what I do know is you have to start some place! The purpose of any fire stop system is to maintain the integrity of a firewall to prevent the spread of fire and smoke. Notice I said "system". Many contractors simply use fire caulk, just filling any cracks or voids. But you want to use a system.

What is a system?

There is more to fire stopping than just applying fire caulk and putty. Each manufacturer tests his product and develops a system proving stating that his product, when installed in a certain way will meet certain fire ratings. Many systems will call for a thin wall pipe, most contractors are using EMT, some fire wool and fire caulk at putty. But also note, they will tell you how much fire wool, caulk and putty to use and how much the tube can be filled.

The basic types of product you will use are fire caulk, applied with a caulk gun or moldable fire putty sticks. In addition to that you will find fire pillows, sleeves or pass through devices, mortar and foam products. Again, just don't by a product and stick it in, you may end up pulling it back out!. Have a system.

As for the fill product or fire wool or mineral wool as it is sometimes called, many times this is over looked. Each system will specify how much fire wool or mineral wool is needed. You will find it available in several different forms. Some is available in 2 foot by 4 foot sheets, usaully coming in a bale of 8 sheets or so. Buy it by the bale, you will use it and if you don't have it, you don't have a system. I used to see it sold in small 5 pound bags, almost like cotton candy, many contractors liked the smaller size and it was also easier to work with. One company makes it almost like a pack of french fries with pieces 4" thick (a common size for systems) four feet long, making it easy to dispense. 3M now has a product called PM4, that comes in a small pack on a roll. This is one of the nicer fills I have seen although it is on the expensive side. Whatever you use, use the right amount your system calls for.

More and more common in fire stop products, especially in the low voltage field are sleeves with intumescent fire putty built right in. Many contractors prefer these products because of their ease use. While these products tend to be expensive, they are fast to install and are much more fool proof then other types of systems. Abesco products has a round split sleeve that allows it to be used in retrofit applications.

Who makes it?Hilti is probably one of the bigger players in fire stop. They do an excellent job of getting to the architects. Many projects are specified Hilti. 3M, Grace, Abesco and STI (there are many more I know!) also have a full line of fire stop products. Most electrical, mechanical and drywall supply houses handle fire caulk along with most of the big do it you self stores.

My disclaimer- Again, I am not a fire stop expert, nor does this article even begin to scratch the surface of fire stop systems or applications. Just remember the importance of knowing what you are doing, and use brand name products and use their "system".