Buildings undergoing demolition, renovation, or construction are particularly susceptible to fire. Construction sites are typically rich in combustible materials and, once started, fires often spread with extraordinary speed, putting lives in danger as well as the work in progress.
It’s a good idea to have a fire protection engineer involved with any substantial construction project from the design phase forward. This is required in some instances, and the benefits multiply as the project in question is large, complex, or unusual. Also, the expense of using a fire protection engineer may be cancelled out by insurance and other savings.
It’s highly beneficial, also, to involve local code and fire department officials in your project from the outset. Code enforcement authorities can assist your design team in incorporating required fire protection measures from the design phase onward - the most efficient and cost-effective time to do so - and to plan code compliance, both as to construction operations and the finished building.
Fires in partially-completed structures can be extraordinarily dangerous. Sprinkler systems and fire walls may not be in place. Portions of the construction may be inaccessible. Hazards obvious under normal conditions may be undetectable or unnoticed during an actual fire. By definition, buildings under construction are changing constantly. If responders have never before seen the jobsite, their task becomes all the more challenging.
Perhaps the most perilous situation can arise where a project is being occupied in phases. Obviously, in a fire situation, it’s critical to know which portions of a partly-completed project are occupied and which are not. In the planning phase, water lines, control panels and fire pumps can be located logically, to support the sequence in which portions of the project will be occupied. Locations for the unloading of materials and (especially) the storage of flammable materials, can be strategically placed, as well as means of egress, fire extinguishers, etc.
Once site work begins, an onsite command post should be established, and a fire protection program manager designated. The command post should have the drawings and plans for construction, emergency information, means of communications, keys and equipment for use by the program manager and emergency responders. This is the time to establish, and ensure compliance with, rules requiring the regular disposal of waste, and the safe storage of materials (especially combustible materials) in locations equipped with fire extinguishers and remote from operations, or local conditions such as wildfires that could increase the risk of combustion.
Formal pre-incident plans are highly desirable, and are required for some projects (whether by code, or as part of an insurance and risk-management program). While permission from the owner will usually be required, providing construction plans to local fire responders can aid them in their pre-fire planning. Data from construction plans can be stored electronically, and retrieved during an actual incident, to aid in dispatching resources in response.
In all events, frequent site visits by the fire department are invaluable in aiding both your fire program manager and emergency responders in developing and updating response plans, and creating a basis for more rapid and effective decision-making, should a fire occur.
The sitework phase is usually the best time, also, to plan for water supply and access, sufficient all-weather roads, and adequate means of escape ? not only from the building being constructed, but from the surrounding site. Multiple exits from the site perimeter are desirable, if practicable.
As construction proceeds past the sitework stage, progressively there will come onsite a host of fire hazards, for which precautions must be planned. These typically include welding operations, temporary heating equipment, electrical equipment, flammable and combustible liquids and gases, explosives, combustible materials such as formwork, and even things such as employees smoking.
One critical need is to properly store and label explosives and other highly hazardous materials. Firefighters may be killed or injured if unable to identify, quickly and reliably, where such materials are present. This should be coordinated with local authorities, as permits are often required, and measures taken to secure hazardous materials against terrorists, juveniles, disgruntled employees, and aspiring arsonists. Here again, a fire protection engineer can help reduce these hazards through planning, coordination, and liaison with code officials and emergency responders.
During building erection, additional considerations come into view. A lighted stair must be constructed for use by construction workers and emergency responders. It should have identification signs, and fire extinguishers on each level.
Functional standpipe systems are also essential in buildings under construction. In the case of taller buildings, local codes may require the availability of an elevator or hoist for fire services.
Another area of concern during erection is the combustibility of materials, notably formwork (which may be limited by code, or restricted to lower elevations) and materials used in erecting temporary enclosures. Non-flammable or fire-resistant materials should be used whenever practicable, and care taken to keep these items away from sources of ignition, and to ensure that they will not obstruct exits in the event of fire.
As construction advances to the upper stories, care must be taken to secure materials on upper floors which, in addition to posing hazards to construction employees, could be blown onto firefighters during a fire in windy conditions. Also, roof operations often present fire safety issues - such as where torch-applied roofing, or tar kettles, are employed.
Once interior trades are at work, and the building is to be enclosed, one critical coordination issue is that whereas the required stairway must be enclosed when the building exterior walls are in place, some jurisdictions permit the stairway to be enclosed in tandem with the exterior walls, on a floor-by-floor basis. Others require the stairway to be fully enclosed first.
Part of this phase will be the installation and testing of alarm, detection, sprinkler, standpipe and other fire protection systems. This generally requires coordination with items that must be installed and inspected before they are concealed, such as electrical work and fireproofing.
As work approaches the punch-list phase, special attention may be required to detect and to ensure safety, where alarm, sprinkler, or other fire safety installations remain incomplete, or may be inoperable.
Partial occupancy may also present issues governed by local codes, such as provisions governing what levels of completion other conditions will permit occupancy of building levels above and below levels still under construction.
Another key element in partial-occupancy situations is the completeness of exit enclosures and parts of the building required to gain access to them from the occupied portions.
The keys to success in minimizing risks from fire during construction are: