Ask the Expert: Laminate Glass
In this installment of Ask the Expert, we put your questions on laminate glass to our balcony expert, Nick Haughton.
What’s the situation with laminate glass balustrades?
Laminate glass balustrades are currently banned, although they are allowed for doors and windows. At Sapphire we’re active testing new solutions and lobbying the government to review the regulations and provide an exception.
Monolithic is permitted but carries safety concerns in the event of breakage as it leaves a void until replaced. Crystal Linear is a new temporary solution available from Sapphire, contact firstname.lastname@example.org for more information.
Watch our test comparing monolithic and laminate glass in a balcony fire scenario here.
Are the regulations continuing to change?
Yes, the first major part of implementing Hackitt was the combustible cladding ban which is well underway. However there have been several queries and challenges in implementing the ban causing confusion and hesitation, for example regarding laminate glass and decking.
The second major part is the regulator changes which are just starting, and we are yet to explore the consequences.
I’ve seen lots about different building heights, what is the key height?
Firstly, it’s important to note that the regulations specify that the ban applies to the full façade of buildings over 18M, not only the parts above the 18M line.
This height has been reduced to 11M in Scotland and the government has suggested that this height will be used in defining buildings where sprinklers are mandatory and require non-combustible decking.
New Zealand are following suit, currently consulting on a 10M building height threshold.
So, with buildings below 18m can I use any materials?
Theoretically you may be able to, however, this doesn’t mean you should. After a major London fire in June 2019 involving an apartment block below 18M the government issued advice note 14. This clearly pointed out two things;
1) B4 of Schedule 1 says external walls should adequately resist the spread of fire
2) Combustible materials should be replaced
Is there one test for balconies to show they are either compliant or not?
In brief, no. There are some tests for some components but there are many interfaces that all adjoin to balconies, for example facades, cavity barriers, balconies, doors etc. and there are endless possible ways to combine them.
That said, Sapphire have been carrying out numerous tests with Exova (Warrington Fire) as well as our in-house facilities. We’ve tested various aspects and can provide some of the most extensive test data available for balconies specifically.
What aspects should I consider for fireproofing a balcony?
There are two key areas;
1) Within the cavity to maintain a barrier. This would involve using a fire stop around the anchor connection, like Stubguard™.
2) On the exterior ensuring that not only the balcony components are all non-combustible but also taking additional fire safety precautions. Adding soffits for example helps deflect heat, restricts the flow of oxygen and contains embers should items on a balcony be on fire.
This is particularly important given the prevalence of combustible items stored on balconies. Many residents make use of bamboo privacy screens, have combustible furniture and dry laundry on their balconies giving any fire ample sources of fuel. It is important therefore to limit the spread of fire from one balcony to another through features like aluminium soffits.
What balcony construction types are most common in fires?
Concrete is the most common balcony type in balcony fires. This is because there is often a significant build-up of waterproofing, insulation, plastic pedestals and decking structures which are often combustible. These elements are largely designed out on metal balconies reducing the fire risk.
In our research 60% of balcony fires occurred on concrete balconies while 30% had either combustible soffits or none at all.
About the expert
Nick is Sapphire’s resident fire expert travelling around the UK and abroad to deliver CPDs to construction professionals on a range of topics including laminate glass. Nick’s expertise allows him to aid specifiers in ensuring the compliance of their balconies.