Good seal bad seal

All of those within the supply chain with responsibilities to install, maintain or re-instate a building’s fire compartmentation should be aware of Regulation 7 of The Building Regulations, which requires that building work is carried out using “adequate and proper materials which are appropriate for the circumstances in which they are used” and “are applied, used or fixed adequately to perform the function for which they are designed …in a workmanlike manner”.

When firestopping around electrical and mechanical services and data cables, for example, a number of factors must be considered:

• required level of fire resistance
• what services are contained within the aperture
• how the fabric of the building will react in a fire
• if there will be a requirement for the later addition or removal of services.
• load bearing or impact resistance requirements
• thermal movement or other ambient conditions
• acoustic or other non-fire issues

Products should only be installed as fire tested and systems should not be mixed and matched. Seals damaged by the introduction of additional services should be repaired with the same product.

Poly Urethane foams are rarely tested or suitable for sealing service penetrations. There is a widespread belief that urethane foams intumesce and they are sometimes described as ‘fire foam’ or ‘intumescent foam’, which means they would expand as a reaction to heat, but in contact with fire, PU foams actually melt, degrade, give off black toxic smoke and catch fire – the ‘highly inflammable’ warning label and limitations of use information found on the reverse of cans should be noted.   

Suitable firestopping tested systems for service penetrations are often based on heavy density rock wool ‘coated batts’ and intumescent mastic; the correct type of intumescent mastic must be specified for each application. Acrylic mastics are the most basic in terms of fire performance. Silicone intumescent mastics are waterproof and generally more flexible– they should to be used in cavity voids and other areas where thermal movement of the structure and moisture may occur. Graphite mastics have high expansion capability and the ability to exert pressure. They should be used around cables and small plastic pipes as they will, in a fire situation, displace and dam penetrations as services melt and burn away. 

Linear gaps occur where different components of a building interface. Manufacturer’s application details should be noted. Typically it must be applied in a 1 to 1 ratio, i.e. if the gap is 20mm wide then a depth of 20mm will be required to guarantee fire performance.

Fire doors are very familiar items. but their complexity is often overlooked by those involved and tasked in the installation, maintenance and inspection process.

They differ in 2 main ways from other fire safety components such as fire alarm systems, fire extinguishers and emergency lighting:

1. The others stay aloof from day to day use whereas fire doors are opened, wedged, bashed and otherwise used and abused on a daily basis
2. Unlike the other components they are more often than not installed, inspected and maintained by people with no specific training or qualifications to do so

When looking at fire doors, two key considerations, often overlooked, should be borne in mind:

1. Not all fire doors protect the same level of hazard and some are more critical to the overall fire safety of the building than others
2. Not all fire doors are subject to the same level of usage

If criticality and usage, are fully considered then it may have an important influence on the quality and specification of fire door purchased, for example to what extent they need to be impact resistant. It can be seen that fire doors can be put into four categories; those that are:

1. Critical and High Usage
2. Critical and Low Usage
3. Non-Critical and High Usage
4. Non-Critical and Low Usage

When doing so it will be necessary to take into account both the strategic importance of the building (and therefore to what extent property and business continuity is a key consideration) and the evacuation strategy. Especially if the building has a ‘stay put’ policy, determining which doors are critical must factor in adequate protection for Fire and Rescue in the event of a major fire incident.

Critical and High Usage:

Those looking to make a significant impact on both the fire safety and future maintenance costs of a building should focus on these doors as they could seriously affect life safety. These are doors that must be installed correctly and then effectively managed and maintained, but because they are subject to high traffic usage they are likely to bear the brunt of ‘wear and tear’. An unambiguous Planned Preventative Maintenance scheme is appropriate for such doors.

Issues therefore to be considered:

• Can and should they be held open to create easy access and prevent damage?
• Should they be to a higher quality specification than other doors in the building?
• Should they be inspected to a higher standard than other doors, especially at installation / handover?
• Are they Building Regulations Approved Document M (ADM) compliant?
• Should they be inspected more regularly than other doors in the building?
• Should they be independently inspected and certified?
• Is an effective PPM scheme in place?

Fire doors for the other 3 categories can be similarly assessed

Fire door sets must not be considered in isolation as other fire and smoke separation elements such as fire walls, glazed panels, fire barriers and fire dampers need the same rigour of installation, inspection, maintenance and management, otherwise one or a number of weak spots within a buildings fire compartmentation will result.

Regulatory Reform (Fire Safety) Order 2005 has focussed those responsible to take compliant installations of passive fire protection components seriously; hence the trend to select contractors who are in third party accreditation schemes operated by a UKAS audited certified body.

Mark Williams is the Managing Director of Checkmate Fire Solutions. For more information visit www.checkmatefire.com 

Published December 2015