Lawrence Webster Forrest (LWF), Fire Engineering and Fire Risk Management Consultants
Lawrence Webster Forrest (LWF), Fire Engineering and Fire Risk Management Consultants



Navigation

Client login
Forgotten password
Follow us on Twitter Follow us on Facebook Subscribe to our blog

Lawrence Webster Forrest
Legion House
Lower Road
Kenley
Surrey
CR8 5NH

Tel: +44 (0)20 8668 8663 Fax: +44 (0)20 8668 8583
E-mail: fire@lwf.co.uk

Fire Engineering Design and Risk Assessment - Sprinkler Installation Design - Part 33

Posted by LWF: 12/02/2018 13:22

In LWFs Fire Engineering blog series for Architects and others in the building design industry, we have recently been discussing the design and installation of sprinkler systems in new buildings. In part 32, we looked at how sprinklers can work within atriums and where there is a sloping roof or soffit. In part 33, suspended ceilings and pipework systems will be discussed.

A suspended ceiling is used to lower the ceiling height of a given room or floor and causes a void between the suspended ceiling and the floor above. Any space of depth 0.8m or more requires protection from fire. One reason for this is that building insurers consider voids of this depth and greater to be a potential storage space. 

In some cases, a void which is less than 0.8m may still require protection, where combustible construction or contents are indicated. Such situations will be highlighted as a part of the fire risk assessment which should identify the level of risk involved. Some of the elements to be borne in mind are how combustible the construction materials are and what fuel load might be expected in the void – for example, fan coil units, type and use of duct insulation, cables etc.

When considering the pipework used as part of a sprinkler system, it can be broken down into two main types of design – Tree/terminal systems and gridded systems. 

Tree or terminal systems are recognisable as such because the sprinkler heads are fed by dead-end range pipes which are, in turn, linked to water distribution pipes which lead to the main water distribution pipes. When the system operates, only the range pipes which lead to the operational sprinklers and the related distribution pipes will contain flowing water.

In the case of gridded systems, water is fed to the sprinkler heads via tie pipes, which are provided for by more than one distribution main, which can also be referred to as a track. Such systems may or may not be connected to the main water supply. 

A gridded system is more complex than a tree system, as each sprinkler is fed from more than one direction. This means that during a fire, it is likely that water will flow through all the pipes, instead of only the one feeding the sprinklers in use.

Gridded systems can prove more economical to install as the hydraulic load is spread over a greater number of pipes which are smaller in diameter than in a comparable tree system. They are most commonly found in buildings which are high hazard with large bays and flat or sloping roofs.

In part 24, LWF will take a look at fully hydraulically calculated pipe arrays, now used in preference to pre-calculated pipe sizes. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.

Lawrence Webster Forrest has been working with their clients for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact Peter Gyere on 020 8668 8663.

While care has been taken to ensure that information contained in LWF's publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.

Leave a reply

  *

  *

 


CAPTCHA Image

[ Change the image ]


*Required

Subscribe to our fire safety blogs

Bulletins
Email Format
* indicates required

FIRE SAFETY BLOGS

  • Fire Safety for Healthcare Premises - In-Patient Mental Health & Learning Disability Facilities continued - Part 9

    In LWF’s blog series for healthcare professionals to give advice and information on best practice of fire safety in hospitals and other healthcare premises. In part 8, we began to give an overview of categories of inpatient mental health services. Part 9 will continue with that breakdown with a view to relating fire safety information to those categories of care.Recovery and rehabilitation services are provided for those adults who have severe and long-term mental...

    Read more...

  • Fire Engineering Design and Risk Assessment - Sprinkler Installation Design - Part 33

    In LWFs Fire Engineering blog series for Architects and others in the building design industry, we have recently been discussing the design and installation of sprinkler systems in new buildings. In part 32, we looked at how sprinklers can work within atriums and where there is a sloping roof or soffit. In part 33, suspended ceilings and pipework systems will be discussed.A suspended ceiling is used to lower the ceiling height of a given...

    Read more...

  • Facilities Management & Fire Safety - How people act in a fire situation - Part 5

    In LWF’s blog series for Facilities Managers and those who have an interest in or responsibility for fire safety, we have been looking at how people react when there is a fire. There has long been a preconception that people panic or act irrationally when informed a fire is in progress, but research has shown this is very rarely the case. In Part 4, the frequency of fire alarm soundings was discussed and in Part...

    Read more...

  • Fire Engineering Design and Risk Assessment - Sprinkler Installation Design - Part 32

    In LWF’s Fire Engineering blog series for Architects and others in the building design business, we have been looking at sprinkler installations and how to approach them. Part 31 went through the basics of the spacing and location of sprinklers in terms of maximum allowable spacing. In Part 32, the location of sprinklers in terms of placement, height and purpose will be explored.Sprinklers should be placed where there are no obstructions to interrupt the...

    Read more...

  • Fire Safety for Healthcare Premises - In-Patient Mental Health & Learning Disability Facilities - Part 8

    Fire Safety for Healthcare premises is a blog series by LWF, aiming to give guidance on healthcare-based standards and best practice in fire safety. In part 7 of this series, we looked at health centres and GP surgeries which may have facilities for minor invasive procedures and how that should impact upon the safety provisions and protocols in place. In part 8, those facilities which provide inpatient mental health care and accommodation for people with...

    Read more...

Case Studies

The Wohl Neuroscience Institute - Fire Safety, Strategy & Engineering
Key Facts: Client: King’s Clinical Neuroscience Institute Project Manager: MACE Ltd Designers: Devereux Architects/Allies and Morrison Approximate Size: 7,400m2 Description of the Project:...

Read more..

General Bulletins

Fire - The External Risk
When we consider fire safety, our focus is normally from within, what can we do to prevent the occurrence of fire and how we can limit its damage.  Whilst this is the correct stance to take, we m...

Read more..

Technical Bulletins

Evacuation Modelling - Factor in Human Behaviour
Evacuation of buildings can be analyzed in different ways. Approved Document B (ADB) which provides guidance on meeting the requirements of the England and Wales Building Regulations with regard to fi...

Read more..

Site map | Web development London