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A History of Firestop in the Building & Construction Industry

Posted on 3/21/2017 12:41:26 PM By Sharron Halpert
  

This is the first blog from Sharron Halpert in a series this year on fire protection/firestop in the building & construction industry.

In the world of firestop, we look at a building as a series of boxes.  The goal of firestop is to contain a fire within a box.  This box is comprised of rated assemblies that are walls on the sides and typically floors above and below.  The walls are often peppered with openings to allow for pipes, ducts, cables and what not to pass through.  There may be an array of mechanical, electrical plumbing and sprinkler (MEPS) combinations.  The holes created in the floors and walls to allow the MEPS penetrations should not also allow fire to penetrate.  This is where firestop comes in.  This idea of compartmentation came about from the shipbuilding industry.  That is a tough call with wooden structures.  Once boats, particularly war ships, began to have different compartments connected with ventilation and cables, the compartmentation became more necessary.

Then came the fire at Browns Ferry Nuclear Power Plant.  Imagine looking for air gaps, which could potentially allow for the leakage of radioactive material.  The typical way to do this in the mid ‘70’s was with a lit candle.  The air movement would cause the candles flame to flicker.  During one such test the flame came close enough to polyurethane foam that was used to block air movement around cables.  It turned out that this foam was actually flammable, despite being painted with a flame retardant.  The foam wasn’t designed to stop fire, only to prevent air movement and in turn movement of radioactive material.  In this case the flammable foam cause a fire to chase through the wall- for more information on this fire please see SFPE Technology Report 77-2.

This fire is reported to have brought the shipbuilding concept of firestop to land.  As the industry developed, standards were created to ensure that various manufacturers materials all conformed to the same requirements.  The US has the toughest test in the global construction industry.  One could debate the Canadian requirements are equal, though different; but other countries such as Europe and China have very different test standards. Europe for example doesn’t test for pressure build up or the dynamic impact of movement that occurs during a fire.  China tests only the material installed full depth of a rated assembly; it does not test it in conjunction with the MEPS penetrations.  MEPS penetrations are uniquely different. Imagine the difference between a steel pipe, and insulated steel pipe or a plastic pipe- all of which would have very different requirements in the US standards. They are all treated the same in China. 

The firestop industry was written into the building code in the 1980’s.  These new requirements were often misunderstood and seen as an un-necessary expense.  Contractors working in jurisdictions where building officials required conformance to the new codes found interesting ways to avoid the expensive firestop materials. There were cases where contractors would mix drywall mud with Kool-aide or other colorants to make it appear as though they were using firestop.  In the early stages, many people thought that if the material was red, it was going to be right.  As the industry developed, more contractors learned the importance of this new requirement and more building officials learned how to identify the difference between red drywall mud, red latex caulking and actual firestop material. This practice was seen less often. 

However I was in sales only 15 years ago and a GC dragged empty tubes of firestop from one job to another.  He did this just so the inspector would see the spent tubes in the trailer and assume it was used on that jobsite. How do I know this?  Because when I asked if he wanted to put in an order he laughed at me and told me this was his strategy.  He assumed I wanted to sell the various array of other products in my arsenal so he didn’t hesitate to tell me exactly what he was doing.  He also made it clear that if the local inspector found out, that he wouldn’t buy a penny’s worth of anything from me.  I told him I had more faith in the local inspectors than he did and before the week was out I had a meeting with the local building official. Needless to say, I’m not a great salesperson and I have been accused of been dolled out an extra dose of morals.  At least I can sleep better knowing that the apartments that were going up, had a better chance of being safe even if I lost sales on that project.

Now that you have a basic understanding of where the firestop industry came from.  In my next blog we will look at the early days of firestop, so we can see how far the industry has come in the last 30-40 years.