066 RCI 0717

RCI July 2017

ROOFLIGHTS & ROOF VENTS More than just a smoke vent One way to get the most from a tight budget is to specify a smoke vent which can also provide occasional roof access. James Fisher, managing director of Bilco UK, explains how a compliant, high-quality smoke vent can effectively perform more than one task If a roof will need to be accessed regularly, a fixed staircase and robust purpose-designed roof hatch must be installed to ensure maximum safety. If, however, roof access is only needed occasionally for servicing and maintenance, it may be possible to install one product which can serve two purposes. Saving on costs should never mean compromising on quality. All smoke vents must be CE marked, must comply with Construction Products Directive 89/106/EEC and EU Regulation No 305/2011; and must come with a Declaration of Conformity from the manufacturer. Practically this means you should specify a CE marked smoke vent giving 1m² free vent area, which can also be used for occasional access. You should not use a roof access hatch as a smoke vent, as this will not comply with the regulations. The smoke vent must be opened fully in the event of a fire; either manually, using a switch; or triggered by a smoke detector which causes the actuator to open the vent automatically, even if the property is unoccupied. The main purpose of any smoke vent is to allow the venting of smoke, heat, and noxious gases, to allow any building occupants to escape the building. Once they have confirmed the building is clear, firefighters may 066 JULY 2017 RCIMAG.COM then close the smoke vent using a Fireman’s switch, before tackling the fire. A glazed smoke vent, such as the Bilco SKY-1M, can also contribute a valuable third function, as its sliding glazed leaf allows it to act as a skylight, allowing natural light to fall on a stairwell in the closed position, while providing good access to the roof when open. In the open position, a smoke vent can also be used to provide natural passive ventilation, a fourth function; although it should be fitted with a rain sensor, which will close it in inclement weather to avoid rain causing a slippery floor. Fixed ladder access To allow the smoke vent to be used for access, where possible a fixed ladder, which will not to impede the free vent area required under the legislation, should be installed to provide access to the roof. Fix the vertical ladder on the opposite side of the smoke vent from the actuators to ensure unimpeded opening, and to avoid users stepping over the wind deflectors at the front. There must also be a clear, safe roof area to step onto. The smoke vent itself should also be clear of rooftop obstructions, so it can open, unimpeded Bilco smoke vent used for access to a full 140°. A sliding leaf smoke vent should also be able to slide freely to its full open position. There should be a keyed switch on the staircase to allow the smoke vent to be opened by a technician who needs access to the roof. You may also wish to have a panic button / switch on the roof itself, especially if the smoke vent is to be used as a means of escape from the roof. Because this is primarily a smoke vent, it is essential that any other controls, such as a rain / wind sensor, will be over-ridden by the building fire control system or smoke detector, so that the vent will open unimpeded should a fire occur, even if it happens to be raining. The passage through the vent opening is the most potentially hazardous part of each journey to and from the roof as this is where the ladder ends. This can be made safer with the addition of a retractable ladder extension such as the Bilco LadderUp post. When extended, it provides an additional recommended third point of contact when negotiating the top of the ladder and stepping onto the roof. Once the user is safely back on the ladder and descending, it can be slid easily back into place before closing the vent. A smoke vent does not necessarily need to be a bespoke product; a high quality standard product can often provide both sufficient smoke ventilation and roof access. Using one standard product for both functions can dramatically reduce costs and also avoids making an additional penetration through the roof. A standard size stairwell smoke vent, giving 1m² free vent area, is quite easily used as roof access, provided that the vent is positioned thoughtfully and an appropriate fixed ladder is provided. A carefully specified smoke vent can provide both compliance with smoke vent regulations and a good degree of safety as an access product. This must be one of the best cost saving measures, preserving quality and safety, while achieving genuine ‘two for the price of one’ value for money. www.bilcouk.com Bilco Ladder-Up post in use


RCI July 2017
To see the actual publication please follow the link above