At the design stage it is necessary to pay attention to the detailing of side guides and bottom bars for smoke and fire curtains.
Side guides and wall interfaces
Side guides ensure that there is a complete system with no gaps for the fire or smoke to get through.
Side guides are available for smoke curtains for some applications but the vast majority of smoke curtains won’t have any, since it is regarded as acceptable for there to be a bit of smoke leakage around the edges of the curtains. By contrast with fire curtains side guides are now not an optional extra for occasional use - they are an integral part of the system to enable it to achieve its integrity rating.
Side guides can either be recessed or surface mounted. A recess has the advantage of lower visibility. It can be created by surface mounting a side guide and then building up the wall around it.
Bottom bars and ceiling interfaces
At the bottom of the fabric there is a weighted bottom bar. This has three functions. Firstly, it provides a weight at the bottom of the fabric so that when the power is removed from the roller motor then gravity acting on the bottom bar weight makes the curtain drop. This assumes that the curtain is a gravity drop type, which most curtains are actually are. It also limits the deflection of the curtain if it is subject to high pressure differentials or air velocities. The other function, which applies to all fire curtains and some smoke curtains, is to ensure that there is a seal when it hits the floor.
Since smoke curtains are inevitably mounted at high level and architects normally want them to be hidden away, the bottom bar is the only component that is visible in normal use, when the curtain is rolled up.
Depending on the type of ceiling and the extent to which it is acceptable to see the bottom bar when the curtain is rolled up, a choice has to be made between a simple channel bottom bar (perhaps with a loop for better sealing if the curtain descends to the floor) or a sprung bottom bar, which accommodates any possible unevenness in the ceiling soffit.
This whitepaper explains the differences between smoke and fire curtains, the standards which they comply with, and how to install, test and maintain them.
Join Paul Compton, Technical Director at Colt UK, from 12.30-13.30 BST on Friday 23rd October 2015, as he presents a free CPD webinar on the design considerations when integrating smoke and fire curtains into a building.
In this webinar we cover:
- The differences between smoke and fire curtains.
- The standards which each type of system has to comply with.
- The design aspects to consider when integrating these systems into a building
Paul Compton is Technical Director for Colt, experienced in smoke control, HVAC, solar shading and louvre systems.