6th August 2021 by Technical Director 0 Comments

Does EWS1 affect Balconies?

Following a number of advice notes regarding flammable cladding, the Ministry for Housing Communities and Local Government (MHCLG) Advice Note 21 was published to address issues with balcony decking.  This was released after a residential fire in Barking in June 2019 where timber balcony decking for highrise were a substantial factor in the spread of the fire.

The government updated the Building Regulations on 29th November 2018 to ban the use of combustible materials on the external of buildings over 18 metres. Within this update, the ban extends to any “specified attachment”, which means that it also applies to balconies and decking.  Some buildings completed after this date may still have combustible materials in the external walling or balconies if they were started before the 29th November 2018. This ban does not apply to existing buildings or non-combustible decking.

Existing buildings of any height need to be examined on an individual basis.  This is done via a risk-based approach, using the Advice Notes published by the MHCLG as guidance.  Mortgage companies and building owners did not have the knowledge or framework to consistently apply this guidance, and the competent experts with the knowledge were in short supply.  Therefore, RICS created the External Wall Fire Review.  This provided a standard form called EWS1, which provides mortgage lenders with information in a consistent format which explains the extent of remedial works required.

balcony decking

Balcony Decking Information

Within the EWS1 inspection, the inspector will inspect the cladding and insulation to identify the materials involved including any woodgrain decking, shera decking and fire-retardant decking. The inspector will also inspect cavity barriers, fire-stops and cavity closers.

With cavity barriers, fire-stops and cavity closers, the materials involved are key, but the quality of their installation and their condition are also critical. Hence some decking having the A1 rated decking and A2 rated decking certificates.

The inspector will inspect the balcony decking for the materials involved and should also inspect the installation of the fire-stops around the balcony connections.  It must be noted that the elements here are fire-stops (not cavity barriers) and therefore they must be rated at the same rating as the floor to which they connect (this will be at least 60minutes but most commonly 120minutes).  Due to congestion in this area, and complexity the quality of installation here is often lacking which can lead to breaks in the integrity of the fire-stop.  Also water ingress can damage the fire-stops over time which means that they may sag and expose combustible insulation attached to the balcony decking connector.

decking balcony

Combustible materials on the balcony decking present a high risk of contributing to the spread of fire. The EWS1 process will identify combustible materials involved in the balcony construction, most commonly the decking may be flammable material such as timber balcony decking, plastic composite decking, wood plastic composite decking (WPC) and other composites such as millboard.

It is important to note that there are a range of retail products which could have been fitted to balconies by the resident themselves like non-combustible decking, shera decking, alideck, fire retardant decking, fire proof decking, woodgrain decking.  Some of these products are advertised as “Fire Rated” but not achieve the non-combustible requirements necessary to be identified as low risk in the EWS1 process.

The balcony decking will often be fitted to combustible joists or support structures, these will usually be treated softwood or recycled plastic.  More recent buildings may have aluminium joists installed.

Final Thoughts On Balcony Decking

It is important to note, that even tiled balconies and terraces, will usually include plastic pedestals.  The plastic decking pedestals are usually made from PE plastic which is highly flammable.

It is also important to look for components of the balcony decking which may include resin-based materials, adhesives and materials which are painted over with oil-based coatings.

The balcony decking balustrade, soffit and any attachments on the balcony will also be assessed to the same criterial.  Essentially any material which is not non-combustible will be assessed and usually identified on the EWS1 form as requiring removal.

It is common for surveyors to specify the replacement of timber of plastic composite decking with aluminium decking such as Alideck or Mydeck.  Surveyors may not be aware that Blazeboard offers a unique and compliant solution to meet and exceed the requirements set out in EWS1 by providing a non-combustible solid mineral-based decking board which has the look and feel of wood.

14th July 2020 by Spencer Allen 0 Comments

Balcony Decking Selection Guide for Architects and Specifiers

Following a number of notable balcony fires and the Hackitt report, Approved Document B was changed in November 2018 (and also as amended in December 2019 and April 2019) in that balconies must now be made from materials of limited combustibility.   The MHCLG followed this up with advice that culminated in January 2020, advising building owners that the removal and replacement of any combustible material used in balcony construction is the clearest way to prevent external fire spread from balconies.  This creates not only a challenge for Architects and specifiers to create designs to meet these new technical requirements, but also to achieve the appearance and feel that is expected in a space that is often an extension of the home.

There are key decisions that need to be made in the selection of the appropriate finish, these are set out in the following section.

Free Draining or Drained

Free-draining is used to describe the design where rain falling on the balcony can fall between the decking boards.  Free draining balconies need to have a gap between the decking for the water to drain through.  Free draining balconies don’t usually have soffits, so this can reduce the cost, but it is important to consider what the decking will look like from underneath as this will be readily visible.  Neat bearers and boards that are attractive from the underside also is important.  Its also important there aren’t too many small crevices that birds or insects can nest in.

Drained balconies can be either surface drained or via a lower drainage layer beneath the decking, this can be either via a soffit that catches the water or, an impermeable structure to the balcony itself (such as precast concrete).  With drained balconies, it is important to ensure that the waterproofing extends up the facade at least 150mm from the drainage layer (at least 75mm at doorways).  The selection of the waterproofing must be carefully checked against the requirements of Part B of the building regulations.

Material Performance

Whilst achieving the right appearance is important, it is also important to choose a balcony finish that fulfils the performance requirements:

  • FIRE: Must be A1 or A2-s1 d0 as classified by EN 13501. Note that this applies to EVERY component of the system (i.e including any pedestals, or fixing clips).
  • STRENGTH: Must have the required strength for the application. The strength is tested via the application of a distributed load, but also a point load at the support centres that you wish to use.  The use class of the balcony or terrace will determine the distributed load and point loads that need to be achieved.
  • SLIP POTENTIAL: Slip potential must be considered and be suitable for the application. PTV vales are used to assess this.  Refer to the HSE website for more guidance on this.
  • THERMAL EXPANSION: The material that the decking is made from will determine the thermal expansion. Aluminium has a coefficient of thermal expansion of 24×10-6m/mK.  This means that for example a 3metre section of aluminium will get around 3mm longer at 40°C than it is at 0°  If this is not accounted for in the fixing design, the fixings can break.  Calcium silicate composites can have a coefficient of thermal expansion of 13×10-6m/m.  So, expansion gaps can be smaller.
  • SCRATCH RESISTANCE: It is common for balconies and terraces to have furniture placed on them. Ensure that scratches don’t become a problem during construction or during the lifecycle of the structure.
  • WEATHERING PERFORMANCE: Make sure that any materials specified have had the material and coating tested for longevity. This can be carried out by accelerated weathering testing.  Where the material is subjected to a cycle of UV, freezing and thawing actions to simulate an appropriate number of years.
  • LIGHTNING PROTECTION: Any conductive elements must be considered as part of the risk assessment conducted for lightning protection in accordance with BS EN 62305.
  • HEAT BUILD-UP: Especially if the balcony or terrace will be accessed barefoot, it must be considered that the surface should not build-up too much heat such that it could cause burning. Metal surfaces generally heat up more in the sun than other materials.
  • NOISE: The surface must not generate excessive noise from wind, rain and hail.
PTV

Conclusion

There are a range of materials available, by considering the key performance factors, it the best material for the application can be selected, and will perform for the long term.

Replacement of old wooden deck with composite material
14th July 2020 by Spencer Allen 0 Comments

The Combustibility of Balcony Decking

It’s not just cladding

Due to recent focus on cladding, we thought it timely to write to you to discuss that the issue is not just about cladding, balconies are as much of a concern yet don’t seem to get as much coverage, and the problem can be more difficult to solve because of the limited design solutions available.

Balconies are an essential part of high-rise living, especially during our current period of lock-down. They provide an essential space for fresh air, reflection, a quiet espresso in the cool morning air, and often, smoking!  Architecturally, balconies frequently define the drama of the façade of a residential building and invite the outside in.

The industry has responded to this challenge with a range of aluminium decking systems and until now, the choice has been between one type of aluminium or another.

“We had experience of developing composites for non-combustible cladding, and when we saw the requirement for decking, we set about trialling the same technology for decking boards”.

“We had a number changes to make to the production ingredients, adding higher strength fibre and eliminating water-based colourants, each time testing the end result. We had to consider properties that we hadn’t had to before, such as slip resistance”.

“We are really pleased with the results, we have achieved a non-combustible decking product that would be at home at home.”

Large New Deck in House Backyard
14th July 2020 by Spencer Allen 0 Comments

Advantages of Using Blazeboard for Balcony Decking

The team at Blazeboard is very experienced. They have worked with wood to create attractive designs for flooring and balcony decking. We applied our engineering experience of re-inventing construction materials to create Blazeboard which provides the visual and feel appeal of wood, whilst achieving the non-combustibility requirements demanded by the building regulations.

They are suitable for use in:

  • Balconies at any height
  • Roof terraces
  • Walkways and bridges
  • Fire Escape routes
  • Building cladding

The advantages are many such as the following:

  • “Cut, fix and set out the 145mm wide boards just like wood”
  • “Through-coloured in a range of colours”
  • “fire classification of A2-s1, d0 or A1 when classified in accordance with BS EN 13501:2007+A1:2009.”
  • Quality Materials
  • 15 Year Warranty
  • Unique Technology
  • Highly Experienced Team

15th June 2020 by Spencer Allen 0 Comments

Introduction To Blazeboard: A Premium Balcony Decking Solution

Blazeboard is a non-combustible decking board for balcony decking.

It provides a high-quality, elegant and robust look and feel for both residential and commercial applications. It fully satisfies the requirements set by the Approved Document B 2018 for high-rise residential developments. It is finished in wood grain or grooved anti-slip profiles, making it ideal for balcony decking, terraces and walkways.

Blazeboard was able to achieve this by improving on existing re-enforced cement composite technology. Through rigorous testing, adapting and retesting to optimise the material for high-rise residential balconies.

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