Roof Types and Construction

This week I am speaking about all of the aspects of construction that might relate to roofs. You could take this training idea and use it in any number of ways but we will throw out some suggestions for argument sake.

Make sure your troops know that in many cases the roof of a building is designed to keep the rain out and not much else. Of course it adds stability to the overall building but it is really not designed to take significant weight loads above it's design maximum. Obviously in the Northeast and points where it snows, roofs are designed for snow loading as well.

Framing up a drill for roofs (no pun intended) would go something like this:

* Go to the local building department and determine what weight per square foot residential roofs are supposed to be able to hold in your area.

* Discuss and define the following terms with your personnel: Concentrated Load, Dead Load, Design Load, Undesigned Load, Distributed Load, Live load, impact load.

* Find out from building department what local materials are being used in roof construction in a typical residential.

* Take photos of buildings in your response area during and after construction so you can show your members what the roof support structures really are.

* Review all of the various types of roofs with your personnel and the characteristics of each, how you change your operations for each and any peculiarities which could lead to failure.

*Roof Types: Gable, Gambrel, Hip, Mansard, Shed, Lantern, Butterfly

* Discuss truss construction. Not every type of truss is bad, but primarily prefabricated truss construction materials may be. Truss construction using large substantial members has been used in churches for years. That is not what the fire department has concerns about, but really the engineered truss. Discuss the following bowstring truss, engineered wood truss, open web steel joist.

* Discuss Engineered wooden structural members such as the wooden I beam type.

* Discuss parapet walls as roof attachments and facades and their failure.

* Discuss and review existing roof loads such as HVAC and other machinery.

* Discuss heavy sign loads that may be creating an eccentric load pulling a parapet wall forward.

* Discuss commercial roofing such as membrane roofing that may have to actually cut away to get to subsurface areas. Also discuss the rapid fire spread that may occur with this type of roof covering.

* Discuss fires that have occurred while roof repairs were being made to commercial roofs using hot tar, and liquid propane burners up on the rooftop.

* Talk about the tools and equipment that should be brought to the roof.

* Talk about the dangers of locating the roof edges in heavy smoke conditions.

* Talk about two means of egress for crews operating and a number of other safety tips.

This is not all inclusive but you should have enough material to research in IFSTA or Delmar publications, coupled with your own digital pictures of your own community to create a good drill and get the personnel to focus on just this one aspect of building construction.

Pete Lamb
Copyright 2013