Fire Protection & Design Section: New Ideas in Firestopping
The basic principles of fire safety in buildings have been known for a long time. There are three principles that are old, simple and straightforward. They are:
- Reduce fire incidence-prevention.
- Control the spread of fire and smoke-sprinklers & fire barriers.
- Provide adequate escape for building occupants-fire escape exits.
The second of these principles, controlling or preventing the spread of fire and smoke, is one focus of this article. Specifically, we will address how improper pipe penetrations through fire-resistant rated floors and walls fail in some aspects of addressing this principle, despite meeting current code requirements. We will also discuss the impact of pipe penetrations on other, newly recognized health and insurance/liability issues within a building. We will address new technologies and products that not only improve firestopping for various types of piping, but also address these new public health issues.
Increased Recognition of Firestopping ImportanceYears ago, firestopping was not viewed as a very important issue and was usually done by simply stuffing old newspapers into the open voids around the pipes and topping them off with a regular concrete patching mix, or in some cases, nothing at all. Over a very short period of time, concrete patching will crack, crumble and eventually disintegrate. Installing concrete patches around pass-through pipes creates a terrible situation for pipe expansion and contraction, as well as regular building settlement. This old method also allowed heavy smoke transmission, which is a critical issue, since, as we now know, most deaths in a fire occur from smoke and toxic fume inhalation, and not from actual contact with the fire.
Fire Test Standard for Pipe PenetrationsIn 1981, a committee of experts on fire safety developed the ASTM E-814 Through Penetration Fire Test Standard. This fire test method was included in the building codes in 1983. It has proven extremely useful in establishing new products and methods of firestopping for all types of pipe penetrations, including plastic piping. Because of this new test standard, plastic piping systems could be safely installed in all types of buildings, including high-rise construction (see Figure 1). When plastic piping systems were first approved for use in plumbing systems, it was thought unsafe for use in fire-rated type construction. Subsequent testing has proven otherwise.
There are several testing laboratories that now perform the E-814 tests, providing listings and ratings for manufacturers and their various types of systems and devices. The F ratings mentioned in this standard specify that no flaming occurs within the F rating time period through the unexposed (non-fire) side of the penetration. The T rating records the amount of time it takes to raise the temperature to 325? above the ambient temperature 1" above the barrier on the penetrating item. No measurements are taken for smoke development or smoke transmission.
Sometimes more protection is desired for a penetration protection device than simply passing the ASTM E-814 fire test standard. A pipe penetration sleeve device may need to: a) Be structurally sound; b) be able to secure the pass-through piping; c) provide for pipe expansion and contraction; and d) prevent heat transfer for metallic pipe through the fire barrier (see Figures 1-5).
ProSet Systems pioneered the use of cast-in-place sleeves for use prior to pouring concrete and cored sleeves for insertion into cored holes through existing concrete slabs. These products provide protection not only for preventing fire spread, but also preventing smoke and water leakage. They secure the pass-through pipe, meet required F and T ratings, and provide for pipe expansion and contraction (see Figure 2.)
What Other Kinds of Innovation Are Needed?Many of today's modern buildings provide fire sprinkler systems. Sprinklers have proven to be the best line of defense for containing fire spread within a specific zone. With that in mind, it has now become very important that the penetrations are able to prevent the large amounts of water produced by discharging sprinklers from leaking to the floors below. As an example, the 27-story NCNB Plaza Building in Fort Lauderdale had a fire start on the 10th floor. A lit cigarette ignited a couch in an office suite. The sprinkler system operated as designed and quickly extinguished the couch fire. However, the high-pressure spray caused heavy water damage because of penetrations that allowed leakage from floor to floor. The fire damage was estimated at only $1,000, while the water damaged exceeded over $100,000. This kind of report is now a common occurrence, making water leak protection a critical requirement.
Other Health-Related RequirementsWater related health claims have increased dramatically in recent years because of mold that has developed in buildings due to uncontrolled water flow from fire sprinklers, roof leaks, fixture overflow, pipe and condensation leaks, among others. Mold claims reached $8.5 billion in 2001. With this rapid claim escalation, some insurance carriers are now denying mold coverage in certain states.
Since moisture is essential for the growth of mold, controlling the spread of water to hidden areas is a logical first step in solving the puzzle. When water leaks from floor to floor, it is very difficult to remove all the moisture between floors and walls that could foster the growth of mold. The ability of waterproof penetrations to prevent water leakage between and through floors is essential in starting to control this problem. This protection would be further improved by using an emergency-type drain system built into each floor to remove the water that accumulates due to the waterproof penetrations.
Mold growth is now known to create serious health and liability risks that were never previously recognized. I believe that it makes sense to protect against this potential health and liability threat by using all the options at our disposal.
The Importance of Innovation: Cast-In-Place Pipe Penetrations-Beyond FirestoppingCast-in-place penetrations were originally designed to prevent fire and smoke transmission through floors and walls. But these penetration protection devices opened the door for many other improvements and benefits. First, there is the ability to waterproof the penetration. Also, cast-in-place sleeves are anchored and secured in the floor or wall with a built-in anchor ring water stop and should not reduce the structural integrity of concrete. They will support the weight of the pass-through and connecting pipes when full of water. This can serve as the pipe support and hangers (see Figure 3). They are able to work in conjunction with pipe expansion and contraction systems where the pipe is allowed to move up or down, or to be rigidly anchored at the penetration, as specified by the engineer. As an illustration, there is no problem with expansion and contraction movement with cast iron drainage piping. It just needs to be anchored in at the penetration (see Figure 3).
Cast-in-place firestop sleeve devices will address a number of pipe penetration issues that provide additional protection for the building.