Danny Forshaw, UL Senior Project Engineer, examines the critical functions of ironmongery for door sets and explains the key issues around their testing and classification.
Danny Forshaw, Senior Project Engineer, UL
Ironmongery, door hardware and door furniture are terms used to describe the essential additions to a fire door blank and frame that make up a door set and help ensure it functions properly. Fire door sets and final exit door sets need locks, latches, hinges, closers and release mechanisms in order to open and close during normal function. These important items not only have a physical functional requirement, but they contribute to the fire and emergency performance of the door set.
It is essential that these important components follow specifications, function properly and have the required level of durability to ensure they remain fit for purpose. Like most products with moving parts they break, wear out, become damaged and require replacing.
When door hardware needs to be changed, it is essential that the new items match the original specification as the fire or emergency function of a door set might be compromised after incorrect or incompatible replacements have been installed. For example, if the hinges are replaced with smaller hinges because they are cheaper, the door leaf may be too heavy and drop in the frame, increasing the gap between frame and door leaf, in a fire situation that would allow smoke and flames to pass through. A larger hinge could cause premature integrity failure of the door set due to localised burn through at the door/frame junction.
Many hardware products have European standards that govern the test and performance requirements for each type of product, including performance declaration and labelling requirements. These vary slightly from product to product as will be shown in this article, but some key characteristics are as follows:
CE marking requirements detail the required physical performance characteristics. However, something that is common in this sector of manufacturing, is the use of additional voluntary independent Third-Party Certification (TPC) which has a high level of scrutiny and attestation of conformity assessment.
Independent TPC typically has additional surveillance and sampling requirements to verify performance. Although voluntary, they are popular for added confidence in the product’s performance, due to the robust nature of conformity assessment from an accredited certification body. Regular audits of the factory production control systems and independent market surveillance testing requirements add value to the manufacturer thus differentiating their products from mandatory conformity assessments such as CE marking.
Within most buildings there are many fire resistant door sets that people use for pedestrian access into rooms, into the circulation spaces and into exit stairs as examples. Fire resistant door sets require self closing devices to help ensure that they are closed in the event of an emergency, ensuring their fire resisting performance.
Doors in a building’s main areas come with heavy foot traffic and many opening/closing cycles throughout their life cycle. So door closers must be robust and have an appropriate power rating to ensure the door closes fully into the frame after each opening.
Testing of closers focuses on durability and function:
Each tested closer is marked with a six-digit number which indicates the achieved performance classification after testing: 3 | 8 | 4 | 1 | 1 | 3
Within buildings, fire doors are often propped open to allow ease of access or better ventilation. In such instances a failsafe release device should be used to hold open the door. Unlike door wedges, fire extinguishers, or any other object used, failsafe release devices have been designed to automatically release any held-open doors if the fire alarm system is activated.
EN 1155 Building Hardware – Electrically powered hold-open devices for swing doors mandates required testing, such as:
Once again, the devices are classified with a 6-digit code:
In the event of an emergency, occupants must have an unobstructed escape route to a place of safety i.e., outside the building. To reach a safe place, occupants in most buildings will need to pass through doors on the exit route and certainly when exiting out of the building. It’s vitally important that as people exit, they are not hindered by locked or difficult to open doors. So easy-to-use opening mechanisms are used to help ensure a continual progression on designated exit routes for people in the building to exit without delays. Push pads, crash bars and thumb turn locks are all utilised depending on the occupancy type, the expected number of people and the building’s use.
Two standards are used to determine suitability:
EN 179 Building hardware – Emergency exit devices operated by a lever handle or push pad for use on escape routes.
EN 1125 Building hardware –Panic exit devices operated by a horizontal bar for use on escape routes.
Both standards prescribe a range of testing requirements — some have a pass-fail target; some offer a threshold level of classification. Unlike the six-digit number for door closers and hold open devices, these devices are classified with 10 digits as shown in the tables above.
The correct specification of hinges is vital to the required door set performance. They perform a significant function for fire door sets, keeping the hinged side in place during the event of a fire. If the door hinges were to melt quickly, falling doors would expose people and responding fire personnel to smoke, heat and flames.
Depending on the end usage, most hinges require testing for use on fire door sets. Single axis hinges, the type most used, have test requirements outlined in EN 1935 Building Hardware – Single axis hinges requirements and test methods. They are as follows:
Door hardware is crucial to door sets’ fire resistance performance and to help ensure safe exits from building during an emergency.
Third-party certification assists end users with product specification, verification, maintenance, and remediation.
Incorrectly specified or installed hardware can impede fire resistance performance and/or prevent a safe exit from the building during an emergency.
For more information on hardware testing contact UL, here or visit the team on stand FI2002 at FIREX International between 17-19 May at London’s ExCeL to find all about third-party certification and its role in the fire safety industry.
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