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 29^th 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 29^th 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.

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.

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 blazeboard.

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.

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.