Frequently Asked Questions

1. What is firestopping? Firestopping is a method of containing smoke and fire by establishing fire rated assemblies in construction and maintaining those barriers through fire rated caulks, mortars, putties, intumescent collars, and intumescent pillows
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2. Some products claim to be intumescent... what does this mean? Do I need it and why? "Intumescent" means that material expands when exposed to fire or heat. In the case where the penetrants may burn or melt, intumescent materials may be the only form of adequate protection. Even in cases where the penetrants don't or burn or melt, intumescent materials offer the advantage of being able to expand and seal many cracks or gaps that may have developed or be the result of improper installation. many passive, non-intumescent firestop materials function by drawing heat away from the penetrants thus preventing them from burning through the firestop.
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3. What questions do I ask myself in order to make good decisions about firestopping? It depends on just what your concerns are.. If you are a specifier, you need to know what products and systems best suit your application. If you are a contractor, you should have these same concerns before you think of price. If you are an inspector, your concerns will be "did the specifier make the right choices and did the contractor do the job right"
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4. What questions do I need to ask in order to be sure that I have the right products and systems? It is important to understand that it isn't just the question of filling the space around the pipe or cable. In firestopping you have to consider the construction of the barrier, the size of the hole, as well as the size, number, type and materials of the penetrants. These variables along with the firestop material are a system. Each individual system requires a specific product. i.e. A metallic pipe through a concrete floor would be the penetrant, mineral wool and caulk would be the product to fit the system. You must determine the best product for the correct situation.
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5. What are the questions that I should ask in order to determine the right system for use? What type of construction am I dealing with? What is the hourly rating? What is the barrier made of and how is it made? gypsum board? masonry? concrete block?
How big is the opening? How big is the annular space around the penetrants?
What type of penetrants? Conduits? Metallic or non-metallic? how many? How big? Pipes? Are they vented or unvented? Cables? What type? How many?
Are there any special considerations in this particular application? Will pipes move or vibrate? Is there unusual expansion and contraction? Will there be the need to modify the penetrants frequently?
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6. How do I know if the right system has been chosen? This is a tough question. Specifiers, installers, and inspectors need to familiarize themselves with commonly used products. The best source of information is the manufacturers themselves. Additional information can be retrieved from the UL® Fire Resistance Directory (beginning with the 1990 edition). It is important to understand, however, that the UL systems show the limitations of the test and not necessarily the limitations of the products. Get to know the limitations of the products. Ask manufacturers for guidelines on the use of products.
What limitations are there in the way of annular space requirements, depth of material used, limits on size, number, and material of penetrants? Everyone is conscious of liability these days. Reputable manufacturers are generally pretty honest about the limitations of their products. When in doubt...ask for help! The manufacturers of firestop products have performed more fire tests than anyone else. When you have a question, take advantage of their knowledge and experience.
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7. The application that I have is not the same as those in the UL Directory... What do I do? This is a common question. The fact of the matter is that the manufacturer cannot test every application and every variation. The testing is usually performed with the intent of generating engineering information to help you make the right decision. Some products have a broader range of applications than others and may not require testing every variable. In general, passive materials (non-intumescent) are less sensitive to variations within the scope of their intended use. Intumescent materials can be more sensitive to the variations in dimensions, numbers, and types of penetrants, etc.
Look for similar applications. Look for performance in similar size opening with a similar annular space (or indication that the product is not sensitive to annular space variations) Look for performance with similar types, sizes, and numbers of penetrants. Ask the manufacturer for a recommendation!
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8. People used to fill up the hole with building materials found on the jobsite. What's wrong with stuffing fiberglass in the holes? This is a common and sometimes fatal misconception. Materials have specific purposes. When used for these specific purposes, they do a fine job. Fiberglass, for example, is a fine insulating material. While it's true that the glass itself does not burn, the binders in insulation do. Not only this but glass melts at about 1200* F (649*C)! Actual tests show that fiberglass used as a firestop will melt out in about 5 minutes!
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9. Some of the codes say that I can use materials tested to ASTM E 119. What's wrong with that? The only test method specifically intended to evaluate firestop systems is ASTM E 814. ASTM E 119 is the standard method of evaluating the fire performance of the wall or floor that contains these penetrations.
ASTM E 119 is actually too restrictive to use for penetrations. When interpreted literally, it has great restrictions on thermal conductivity. These restrictions would restrict the use of any item that conducts a great deal of heat. Thus things like metal pipes and cables would not be able to penetrate a fire wall. ASTM E 814 makes thermal conductivity an option to be used as engineering information where necessary. Many codes have grandfather clauses that allow the use of E119 materials. It is important to recognize that these materials may not have been tested as firestops!
Products tested to ASTM E 814 have been subjected to the same fire exposure as the ASTM E1 19 procedure.. The added benefit is that they have been tested and have proven performance as firestop systems.
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10. What can an inspector do to help assure the proper system is being used? This question has been a big issue! Some inspection authorities require the contractor or architect to submit typical drawings for a project showing the typical details and how he intends to seal the openings. These drawings must reference a manufacturer's recommendations either from printed literature or a sign off on the actual application. The City of Phoenix is using this method. it was a bit cumbersome at first but now it seems to be working smoothly.
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