Although the construction industry’s performance has improved over the past decade, the rates of death, serious injury and ill health for construction site workers are still too high.
Even, members of the public can also be killed or injured and property adjacent to construction sites put at risk.
The leading sources of heat of ignition at construction sites are open fire category includes rubbish fires, open incinerators, and open trash burners.
The combination of open fire and cutting torch sources of ignition correspond to the high incidence of open flame fires.
The leading materials ignited in construction site fires are rubbish/trash; growing/living forms, including grass, trees, and brush; and structural members/framing materials.
When a building is exposed to high levels of radiated heat, there is not only a hazard to any combustible material on the outside of the building, but also to the combustible contents of a room.
The most commonly found combustible material on the exterior of buildings is wood, which will ignite spontaneously at intensities above 0.8 cal cm – this equates to the heat output from a significant and nearby fire.
Where there are a number of timber framed structures being built on one site, the risk of fire spread from one building to the next must also be considered and controlled.
The installation of non-combustible materials, such as the early completion of external façades, can help to achieve this.
As the protection of a timber frame structure relies on the materials which cover the frame (for example, plasterboards, tiles, insulation) which are fitted during the construction phase, a greater boundary distance may be required than when the building is finished.
One way of reducing the required boundary distance is to install compartmentation as works progress, to reduce the size of the elevation down to the area between the two compartment walls.
Another option is to build the external fire-resisting masonry skin in tandem with the erection of the frame, so that the building replicates its final design as works progress, rather than as a separate phase.
There is an increasing trend towards the use of fire engineered solutions, such as smoke control systems, to extend travel distances within completed buildings.
But during the construction phase these systems will not be commissioned and operational and therefore it may be necessary to install temporary additional exits or compartmentation.
On most new construction projects it will not be possible to rely on the principal staircases, as these will not be in place and fully enclosed with fire doors for the entire construction phase.
It is normal to use external scaffolding as part of the escape route, and this should be kept clear of obstruction such as diagonal bracing.
Any other openings, including windows, which are not of fire-resisting construction, should be suitably protected, for example, with plasterboard, proprietary mineral fibre-reinforced cement panels or steel sheets.
To stop a fire spreading and to reduce required boundary distances, a building can be sub-divided by fire resistant walls, and floors/ceiling -compartmentation.
Compartmentation might also form a major part of the fire strategy for the completed building, especially for the larger and more complex structures.
The early installation and completion of compartments can also provide protection during the construction phase.
One way to speed up the installation is to specify the use of pre-formed panels where the frame is delivered with fire protection and insulation already in place.
Temporary compartmentation should provide at least a nominal period of 30 minutes fire resistance.
Like any other fire, fire at construction site can be prevented and it is all parties concerned in the project should work together to ensure adequate and practical measures are introduced during the design and planning stages to achieve the highest standard of general fire prevention at construction site.
Source : World Construction Network and Construction Site Fires, U.S. Fire Administration, Topical Fire Research Series, Volume 2, Issue 14 and Fire Prevention on Construction Sites, CFPA Europe.
(this article written for 1BINA.my)