Hello all
Can anyone read over my paper for class? if there is any corrections can you put in ( and make it red ) any help would be appriated..

Kacy

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Code:
 Heavy Timber Construction- (Does Size Really Matter?)
Presented By: Kacy Thompson, Shant Nazarian, Mike Newton
Fire-4 Group Project
Squad- 4


	Heavy Timber Construction also known as Type IV Construction.  This type of construction isn’t respected as a fire fighters stand point as it probably should be.  There are been fighter deaths in heavy Timber Construction and maybe it was because the lack of pre planning or under estimating the structure and knowing what it can do and can’t do or maybe it was just poor judgment.  Me and my crew will be explaining Type IV- Heavy Timber Construction, how it’s built, what the structure consist of, the requirements of Heavy Timber, determine the effects both positive and negative, lessons learned, what improvements can the fire service make
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	Type IV- Heavy Timber Construction consist of these types of structural components, Exterior and interior walls and their associated with structural members that are of noncombustible or limited combustible materials.  Other structural members include beams, columns, arches, floors, and roofs, are made of solid or laminated wood with no concealed spaces.  Heavy Timber construction was used in old factories, mills, warehouses, churches, it is rarely used today.  The dimensions of the wood structural members should be as follows, Columns-floors= 8”x 6”, Roof= 8”x 6”,                   Beams/ Girders--floors= 6”x 10”, roof = 4”x 6”, Laminated arches—floors= 8”x 8”, Laminated arches—roofs= 6”x8”.  The exterior bearing walls have a 2 hour fire rating; the exterior baring walls have a 1-2 hour rating. Let’s now talk about a floors system of a Heavy Timber structure. Usually consist of floor planks of 3in splined or tongue-and-groove flooring with ½ -inch plywood or 1-inch floor boards laid on diagonal.  Let’s now take a look at a roof system of Type IV- Heavy Timber. 2-inch splined or tongue-and-or groove planks, 3-inch laminated planks (highly combustible when heated).1- 1/8 inch exterior plywood.  Having the knowledge of Type IV as a fire fighter on seen is should know what he’s tactical objective is to open the roof. Knowing that the roof can consist of laminated wood (very combustible when heated, rapid fire spread) or tongue-and-groove planks (can cause ventilation problems).  To make these timbers strong and safe they are usually installed with Anchor bolts, Metal shoes, and bearing plates, metal straps, shear straps, metal angles.

	Now let’s talk about the pros and cons of Type IV- Heavy Timber as a fire fighters stand point.  Fires in Heavy Timber structures usually are not an immediate collapse threat heavy timber can still be able to support the load after heavy charring.  While unprotected steel beams collapse much earlier during a fire, a heavy timber beam can be sand blasted after a fire and left in service(after normal fire damage) The massive size of timber elements allows them to burn for quite some time before they collapse. Usually, the massive fire that they produce, if not extinguished early, chases the fire fighter back out of the collapse zone. People often like these Timber structures because the feel of being comfortable, the strength, and security of the structure. Timber framing allows the home owner to vary the amount of “wood look” throughout the home. By using a mixture T&G, drywall and other materials, you are not tied to one theme of work. Heavy timber structures are very durable, there is a timber building that have gone through hurricanes, earth quakes and are still standing. 
	Well that was the Positives; let’s get to the fun stuff the Negative out look of Type IV Heavy Timber.  Gravity isn’t really our friend when it comes to heavy timber, well any structure that is, the heavier you are the harder you fall, right?  Timber can produce a tremendous (impact load) if collapse occurs.  In addition to the combustible contents of the building on top of the heavy timber can cause a problem if not contained quickly.  Know what you’re dealing with and the contents in side the structure.  For example a heavy timber structure that is a machine shop or car auto shop will have oil soaked flooring which will add to the fire load.  I think one of the major problems of   Type IV is the openings in the floors and walls can cause fire to spread rapidly due to the amount of oxygen that is let into the area.  If you were to just look at a heavy timber building you would think, wow that’s a lot of wood, or those are pretty big pieces of wood, right?  As a fire fighter point of view, he’s going to think wow that’s a lot of “fuel to be burned” or if those timbers fall “watch out”!  If a fire company can get to the structure in time then they win if not then that’s a problem.  Every type of construction built the fire tactics start on the drafting board.  All the anchor bolts, metal shoes, bearing plates, metal angles that hold these heavy timbers together do their job under normal conditions, but as far as a fire is concerned can cause a problem.  Heat produced on these parts causes conduction (heat that is transferred through a solid medium).  These Metal parts usually fail before the wood does.  Most common truss system used here would be a scissor truss or an inverted or queen post truss.  All though heavy timber it self can with stand fire for a long period of time, however when the thinner roof boards are consumed fire fighters may fall through roof boards.  The metal connectors or pin holding the heavy truss system together can fail before the timber fails.  We mentioned before that the heavy timber trusses are spaced several feet apart – much further than light weight timber.  Ventilation crews on a heavy timber truss roof may leave the firemen standing on several feet of unsupported rood board.  Another caution to consider is when a heavy wooden timber truss collapse can cause the buildings front, rear, or side masonry walls to fail also.

	Since we got the Pros and Cons out of the way, let’s look at the lessons learned of dealing with a heavy timber structure fire.  When that alarm rings at the station of structure fire, that’s not going to be a good time to think of what type of construction it is or how it can collapse. Rather then waiting to get on seen and decide the if and buts, do it when the first phase of the construction starts all the way through the last phase of completion.  A truck company or engine company should make frequent visits to the structure from when the skeleton components are built through interior finishes to know what their dealing with when it comes time to.  No matter what always do a size up when getting on seen of a structure fire, you need to establish a collapse zone which is the same height of the wall that you place your apparatus’ and crew.  It is always important to know how long the fire has been burning before the time the fire department got notified to the time of arrival.  Not know how many stories the structure is can cause a problem. A four story structure compared to a two to three story structure a four story structure is going to collapse faster because of its heavier load.  Be careful of the inward/outward collapse it gives no warning and can take down other walls with it.  If the building is sprinklerd, tie in quickly and control and contain the fire to a small area. If there are no sprinklers, then hit the area with a 2 ½ inch line with a smooth bore if doing an interior attack.  Strike additional alarms and call for mutual aid early.  Get behind on a fire in a building of this magnitude you won’t be able catch up until the fuel supply is totally exhausted.  “Deputy Chief Ron Ayotte, Marlborough, MA”
	Incident Commanders and crews should always communicate with each other, making sure every one is on the same page; no one is hurt, making sure there are no occupants, the status of the building. 
 
	Last but not least, knowing what fire fighters do know and about the different types of construction do you thinks every single one of them knows what they should? Most likely not!  Started to pre plan the day or night of a fire isn’t probably the best bet.  Requiring that heavy timber/mills be equipped with sprinkler systems and alarm systems would be a good improvement.  As a fire fighter you could never have too much information, the more you have the better, more resources the better, always ask questions, know your surrounding at all times, and establish a danger zone.  Knowing how long the structure has been burning is always going to be key, knowing how it started if it is arson related or what ever it may be that can make a difference.             



   

	  
	The knowledge that we have now about heavy timber construction as a fire fighter or occupant better prepares us in emergency situations or in a fire.  Knowing how a building can collapse, or what its weakness points are will help us out tremendously in our career let along our lives.  Before we took this class we all kind of wondered why buildings do fail under fire conditions, now it’s all making sense to us, building just don’t collapse because they want to, they collapse because weakness accurse in the main structure areas, and depending on the fire ratings of the buildings, the rating elements can only last so long.  Methods of Heat transfer; Convection, Conduction, Radiation transfer through out buildings can cause problems.  We as fire fighters cant wait until the last minute to deicide to save a structure.  It has to come from the drafting board, and visiting the construction site through the Phases of the building in your jurisdiction.  Many fire fighter have dies or gotten injured because they didn’t pre plan like they should have or didn’t have the knowledge that they should’ve had.  I know that me or my team mates aren’t going to get stuck in that type of situation.  Know fire behavior and what it can do, know structures behavior and what it can do. Good luck and Good night!

Sources:
Fire House.com
NFPA.com
Vincent Dunn.com
Fire Engineer.com
IFSTA.com
HowStuffWorks.com