Home>Topics>>Heavy-Timber Wood Truss Roof

Heavy-Timber Wood Truss Roof

Mon, 27 Dec 2010|

Paul Dansbach, fire marshal for the bureau of safety in Rutherford, New Jersey, explains some of the hazards firefighters face in ordinary constructed buildings with heavy-timber wood truss roofs.


Automatically Generated Transcript (may not be 100% accurate)

Hello my name is Paul dance back and welcome to fire engineering training minutes. Today in this session where to take a look at it -- story ordinary constructed building with a heavy timber would trust -- Occupancy such as this with a heavy timber -- truss roof present some unique challenges and hazards the fire service. Let's take a walk inside and take a look at some of those hazards that are created. By this -- of occupancy. When we -- to the building we notice the wide open water -- The lack of interior columns is -- in and of itself in indicator that the building is constructed with some formal trials. The wide open floor area was desirable for the manufacturing processes. That occurred when this building was in use. The ceiling in this building complicates matters certainly creates combustible -- space in the trust law. Sure the fire -- on the first -- of -- occupancy. The fire in all likelihood will not have direct access to the trusses and may not involved crosses in the beginning stages of fire. One of the problems it's created by a building of this age is that parts of the ceiling may not be intact. Whenever the -- open where the ceiling interior finishes missing any fire on the first war would have direct access up and we trust -- and fire extension from the first war. Into the trust -- will be almost immediate. As we -- across the first war this -- we can see these -- span across the building sidewalk to sidewalk in excess of eighty feet. One of the features that we can pick out inside the building is the areas of support. That is where the -- achieve their support. On this side -- we can see -- column has been constructed. Into the exterior -- this is an area we trust is being your support. The -- is supported on this column direct your blogs you. As you -- discussed the ceiling in this occupancy creates a combustible frost -- The decision a flight of quiet in its -- -- will be based upon location the fire and the extent to the wire in that frost law. Several years ago this building was the -- of a fire. The fire occurred in the trust -- the source of ignition -- some mechanical equipment that had been installed and frost law. This building is protected -- automatic sprinkler system. The day of the fire you automatic sprinkler system help acquiring check. The sprinklers were operating on the fire there for the structural integrity of -- was maintained by the automatic sprinkler system Holden of -- -- Fire companies arrived in stretched hand lines up these stairs. From the scene of the fire and extinguish the fire up -- the prospects. Keep in mind that if you are going to access the trust base you need to know how to access that frost law. This is the stairway that the company struck the -- Let's follow that stairway. And see wearily. Okay we're up in the trust -- a couple of points that we need to make up here number one is the height. The height of the trust walk the distance between the bottom word. And the top quarter the trust's. In this building -- approximately ten to twelve feet. And won't marry depending upon the picture of the trusts. What that tells us that we have a very significant a very large cross walk. There can be quite reward volume of fire up in this area. That fire may be concealed. By the ceiling that's -- on the bottom word or at the bottom word of the -- Another concern. If we are going to fight the fire up in this trust -- another concern is going to be do we have access across the trusses. In this building and not every building have the same feature that this building ads is -- stairway. There's a -- that leads to a walkway. -- now walkway. Provided access to mechanical equipment that was in this trust space. That's a concern for us is there are suitable walking servers is there -- suitable surface that's going to support the weight of firefighters stretching a line. That valuable back condition that factor is going to be Paramount to whether or not we can successfully operate in this trust law. The options of a suitable walking servers will almost making it possible for firefighting crews to get up -- the trust loft. -- -- -- -- -- -- -- -- -- -- The flight before. A viewer from the roof of this building reveals there are skylights on the building the skylights provide an opportunity for natural opening. For far -- to get up make -- quick back and get off the roof again we must reiterate. We caution that needs to be exercise -- operating inside in the trust walked underneath the trust were on the roof over trust building. It's their commanders must be acutely aware of the fire conditions the location of the fire. The X -- probability. And the extent of the fire before they commit firefighters above. Into the trust -- or below the -- in -- trust roofed building. Firefighters operating on the roof or on the roof of an adjoining building. -- how literally have a bird's eye view of the fire conditions that may exist in the trust -- If the -- -- commander is receiving conflicting reports. A report from the roof indicating heavy far conditions where heavy smoke pushing out under pressure. And a report from the interior crews on the first floor indicating little fire and little heat. The incident commander must take the report from the firefighters on the roof. The firefighters on the -- Or the roof -- -- adjoining building have a bird's eye view I can see the truth why conditions that may exist in that trust will. As you wrap up let's review a couple points number one this building -- -- heavy timber -- truss -- Number two that heavy timber would trust -- is concealed by its ceilings walls separating the first war from the trust -- Number three. With a wide open floor area when you walk into a building and you -- a wide open floor area and the absence of columns. That in and of itself is an indicator that the building probably contains was constructed with some form over trust. Number four do we have access to the trust in this building. It was constructed -- access to provide access to mechanical space there's a stairway. If you choose to fight the fire if conditions allow you to fight the fire. You need the structural wind up through that stairway. There are many buildings out there that don't have the same feature that don't have that stairway and access will be much more difficult. We'll -- cover a vertical latter we're viewpoint of what life. Have a -- -- thanks for watching this segment acquire engineering training.

Related Videos:

  1. 'Hidden' Bowstring Truss Roof

    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.

  2. Heavy Timber Wood-Truss Roof

    Paul Dansbach examines firefighting problems at a structure in which a makeshift storage space has been built on the truss loft.

  3. One-Story Hybrid Construction

    Paul Dasbach discusses firefighting hazards and concerns at a commercial buidling that is part ordinary construction but with a storage space of steel truss construction.

  4. Bowstring Truss Roofs

    Paul Dansbach discusses the dangers of bowstring truss roofs with Deputy Chief Steve Kalman of the Hackensack (NJ) Fire Department, as well as steps the department took to identify these roofs after the deadly 1988 Ford fire in Hackensack.