Health and Safety is paramount on roof refurbishment projects. Fragile roof decks cause falls – the biggest accidental killer in construction. In 2022/23 there were 40 fatal accidents and thousands of major injuries caused by work related falls from height. No one wants that on their conscience.
Recent revelations regarding RAAC (Reinforced Autoclaved Aerated Concrete) have drawn attention to the fact that school roofs can become vulnerable. But RAAC is not the only roof deck material that you should be aware of, which may be a hazard.
The HSE leaflet, GEIS5 Fragile Roofs: Safe Working Practices lists several roof surfaces which can be fragile. Alongside roof lights and glass, slates and tiles, there are many roof decking materials which can be a danger to life. In addition, the HSE guide, HSG33 Health and Safety in Roof Work identifies other materials to be aware of.
How to identify a fragile roof deck
A roof’s structural deck provides the primary support for the roofing system. Do not take any risks with roof decks; make sure a survey is carried out by a suitably competent and experienced surveyor. Everyone involved in roof work should treat fall prevention as a priority, including building owners and maintenance contractors.
Here are some images from our recent roof surveys showing roof deck materials which can become vulnerable. All these decks have been classified as fragile or potentially fragile materials by the HSE.
What might cause a fragile roof deck?
Challenges that can worsen the risks of fragile decks include both structural and technical issues:
- Point loads (such as those caused by plant and other equipment) which the roof was not designed to take;
- Ponding water which can also cause increased loads;
- Roofs with poorly designed drainage;
- Roof leaks which can have a variety of causes, or more common,
- A poorly designed roof which is experiencing interstitial condensation.
A roof refurbishment where a number of these factors were in play is Carmel College in Darlington, which we worked on with Thornton Firkin and William Kish Architects.
How to investigate a fragile roof deck
Health and safety must be a primary concern when working with roofs. AccuRoof is a roofing specialist including for roof replacement and refurbishment, and our team gives a lot of thought to how to mitigate risks and make the process safe. Larger buildings or those in constant use such as schools, need particular consideration to ensure the work can be done safely.
The first and perhaps safest method of investigating a fragile roof deck safely is to remove the suspended ceiling tiles and take a look from the inside, though it is essential to check that the roof build-up doesn’t include dangerous materials such as asbestos.
The second method is to take core samples of the roof from the outside, however these should only be taken if one can ensure that the risk of deck failure can be mitigated by appropriate measures.
One might think that one could check the roof build-up from the ‘as built’ drawings. However, these do not always reflect what was constructed and may not show any alterations, so ‘as built’ drawings should be viewed with caution.
How to work with a fragile deck
Removing a fragile deck may involve stripping out large areas below to provide appropriate health and safety measures such as crash decks below where operatives are working. In some cases this means that parts of the building cannot be used during the process, however phased roof replacement is possible with an experienced team and good planning.
To quote the Health and Safety Executive:
“Fragile roof incidents are not inevitable. They can be prevented by careful planning, using trained and experienced workers with suitable equipment and employing a high level of supervision.”
Ask for help with Fragile Decks
AccuRoof provides full support for roof refurbishment including schools and public buildings.
- Comprehensive surveys and access to funding advice.
- The right systems for the right job: we are a product neutral supplier.
- Full specification including NBS clauses.
- Drainage design, Condensation Risk Analysis, Cut to Falls insulation design, wind load calculations and bespoke detailing.
- Our ARRC registered contractor scheme of trained and experienced roofing contractors.
- An unrivalled supply chain in SIG Roofing giving you confidence in supply.
- Site monitoring and technical support throughout.
- Robust warranties and planned maintenance advice.
- Our service has its own PI Insurance to give both you and your client confidence.
Talk to us about fragile decks in your estate.
