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'Hidden' Bowstring Truss Roof

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Mon, 21 Feb 2011|

Paul Dansbach shows us another commercial building in which the presence of a heavy timber bowstring truss roof can't be detected from the exterior.

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Automatically Generated Transcript (may not be 100% accurate)

Hello my name is -- -- back and welcome through fire engineering trading minutes. This session of trading minutes will be the third session that we've gone on truss roofs. In the first session we looked at a building and had a heavy timber wood truss roof system. It was a large manufacturing facility and the ceiling on the first war concealed. He would trust is -- -- In the second video we -- that -- mercantile occupancy and occupancy where we might not suspect they truss roof. The truss roof was a steel frame parallel -- -- system. The appearance on top of the roof. Provided a flat -- service which may confuse firefighters' relief firefighters to believe that the building was not constructed with the trucks. In our third goalie -- again looking at -- smaller mercantile occupancy. From the exterior of the structure from the -- side -- from history. We missed some size and use our size of -- are actually asleep. We look at the building and do not see any form of -- would trust. If we move around to the -- side of the building again we woke up we see -- -- wall but what we -- appears to be a flat -- We don't see the large round it -- over roof surface that you would expect the fine with a bow string trusts. Yet this building is constructed with a heavy timber bow string trusts. Where a walk inside and take a look at that roof system. As we get to the front door of the occupancy we noticed a suspended -- and aluminum grid ceiling with piles are in place. At this point we still have no idea that this building has a heavy timber -- truss -- We need to look further into the building where identify the truss roof on this building. As we walk through this occupancy. Heavy timber truss -- system is clearly obvious. A lot -- ceiling will allow firefighters. Are readily identify the fire's location. And to be able to apply -- hosiery. Once again incident commanders need to consider. -- area of involvement what's burning in the building. Is -- a -- fire is a structure fire. Are there other parts of the structure which in the case of this occupancy. There are other parts of the building that are not constructed. With -- Is the fire involving atrocities. If the fire -- in the trusses to we have. The opportunity to apply heavy caliber host free with good -- -- penetration. In a few short minutes to see obvious results about hosiery. Or must we back out and take -- the offensive posture because the fire has involved had taken hold in the trust base. As you walk through the occupants to rediscover skylights. The -- -- provide an opportunity. For quick revelation as they are natural openings that are easily open by firefighters. Again we need to consider where the fire is and what's burning is that a -- fire that hasn't affected the integrity of the -- Or as the fire started out as a content fire. And gain significant headway and is now involving the structures those factors need to be considered before we commit firefighters interior -- -- operations. An exterior roof ventilation operations. As you walk through the structure we noticed there were other rooms and spaces. We must understand the -- -- route that's on each one of these rules we're spaces. The room behind us. Has it -- -- -- roof a flat roof. Independent. Of the heavy timber -- string trucks therefore they fire in this room or space can be fought. Just like any other structure fire that does not involve -- trust group's us. As we get the destruction through the front door we -- -- it. Here is another door that leads directly into the working area of this building. Firefighters can access the building via this -- Through this -- with a hose -- they have direct access. To the trusses. Should acquire B -- the trusses placement of a large caliber whole history with good reaching penetration. Operated from this doorway may darken a fire down. Should that be the case firefighters to continue to operate. From a safe distance while continuing to knock down the main body of fire. Should firefighters place alliance -- and such a manner and the hose stream have no impact on the fire. Up in the trust -- firefighters must withdraw to a defense -- position. Because the fire has gained significant hole in the trust base and interior operations. Are not an option. As the trust is -- heavily involved in fire any danger of. Laps. We're back outside and to reinforce our size of -- where again looking at the beside the structure. And what we don't see from the outside looking around the building particularly at the -- side is the truss roof. We must always suicides up must always look at the building from the exterior for signs -- use -- notify the type a construction root structure. Unfortunately that will not always give us the correct information. Pre plan information. Reports from -- -- reports from interior rooms are all part of the cockpit and I'm going size and any fires. Thanks for watching this section of -- and -- treatment.

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