Passive Fire Protection for Modern Methods of Construction

Promat Australia is due to release our passive fire technical guide on Modern Methods of Construction. Below are some excerpts of high level considerations that should be taken into consideration when specifying passive fire systems in prefab/modular buildings.

Promat Australia has extensive experienced gained over the last 3-5 years working on MMC projects, and understand what is required from design to delivery to ensure life safety and compliance are not compromised.

Introduction

In Australia and New Zealand, real estate demand and the availability and relative costs of skilled construction labor is making the Modern Methods of Construction (MMC) model attractive to developers. This industry shift has implications for fire safety as the nature of buildings comprised of pre-fabricated lightweight systems is such that the types of fire protection used for standard heavyweight buildings may not be suitable. Careful specification is required to ensure lightweight building systems deliver the required levels of fire protection in real fire conditions.

Fire Risks Associated with Lightweight Construction

Studies have confirmed that, under controlled conditions, lightweight wood structures burn and lose integrity faster than their heavyweight counterparts. The faster a building’s structural integrity is compromised during a fire event, the less time there is for occupants to escape and the more dangerous it is for fire and rescue services to conduct search and suppression activities.

While there is less combustible material in a lightweight steel building, fire can spread quickly and cause structural collapse if the structure has not been properly detailed. During a fire, there is a risk of complete failure of the structural lightweight cold-formed steel studs, joists, and trusses. For such buildings, extra care has to be taken to provide additional forms of fire protection such as sprinkler systems and fire-resistant compartmentation.

Specifying Effective Passive Fire Protection Systems

Given some of potential fire safety issues in Modern Methods of Construction (MMC), a holistic design approach to fire protection is needed. An effective fire protection system includes both passive and active fire safety elements. Passive fire safety measures, such as fire-rated barriers, walls, and structural floors, prevent fire spread and progress. Active measures, such as sprinkler systems, take action to suppress a fire.

A key aspect of controlling fire within a Modern Methods of Construction (MMC) is breaking the continuity of combustible material in the line of fire range. The fire resistance provided by walls, floor and ceiling systems is critical in stopping a fire from spreading quickly throughout a building.

Unfortunately, the fire detailing of these building elements is often not considered until late in the process. The connections between modules and between different building elements, especially where they are using different types of lightweight systems, are particularly vulnerable. Furthermore, most fire-rated systems are considered in isolation and how they interact with systems from another manufacturer is not adequately considered during the design phase.

Keep your eye out for the up coming release of the "Promat Passive Fire Protection Systems for Modern Methods of Construction (MMC)." technical guide.