The fire behaviour of naked EPS (Polystyrene) insulation material is very flammable, If the material isn’t properly covered by another fire retardant material or covering which determines the fires behaviour.
EPS is excellent for insulation to the inner side of a wall, for cavity insulation boards, for loose fill insulation, for external thermal insulation systems (ETICS) or for prefabricated composite panels, such as structural insulating panels (SIPS) or steel sandwich panels.
In all of these examples the EPS insulation is covered by an inorganic or metal surface layer. These layers make it possible to fulfil all requirements for reaction and resistance to fire, dependent on the surface material applied.
I asked for assurance from the council that the External Wall Insulation used on council stock meets all fire requirements.
Email sent on 24th June 2017.
Dear Mr Webster,
Thank you for your recent email.
I can provide the following information for re-assurance. I can also advise, any resident that has made contact with the Council in the past few days raising their concerns, have been or will be contacted via email / telephone or have been given the facts, as stated below.
There are circa 1000 Council homes across Rotherham Borough that have benefited from External Wall Insulation (EWI) to help improve the thermal efficiency of properties. These are domestic dwellings, normally 1 storey high. Following the fire at Grenfell Towers at London questions have been asked about the safety of the homes with EWI in the event of a fire.
If you take a piece of the insulation which is installed as part of the EWI product it is possible to set fire to it. However there are a number of steps to the installation process which reduces this risk and provides a finished product which is fire retardant.
The steps include;
Step 1: Remove and repair any loose or defective concrete or brick work which will provide a solid structure in which to install the EWI to.
Step 2: Fix the insulation direct to the existing wall finish with special mechanical fixings.
Step 3: Apply a metal mesh over the top of the insulation board.
Step 4: Apply a full coat of fire retardant render to the whole property.
The combination of these 4 steps provides a product which provides a fire retardant barrier, that has been given a Class 0 rating. A Class 0 rating protects the surfaces from the spread of flames AND limits the amount of heat released from the surface during a fire. It is worth noting that Building Regulations, Fire Safety, Part B specifies that this type of rating is only required for buildings 18m or more, however The Council has gone above and beyond this guidance and provided a class 0 finish on all properties that have received EWI.
The risk of fire spreading via external cladding is extremely low, this is because the insulation is encased in fire retardant materials, in the same way as insulation is sandwiched between bricks in a traditionally built cavity wall property.
In addition to this the EWI installed in Rotherham is a different system to the curtain walling product used at Grenfell Towers and other high risk buildings across the country. Curtain walling is installed on metal tracks which means that the panels are not flush to the building, early indications are that this style of fitting acts as a chimney which enables flames to take hold of the insulation and spread.
The Council is keeping abreast of the latest developments following the incident at Grenfell Towers and will act accordingly as and when further guidance/legislation is issued. The Council also has a close working relationship with South Yorkshire Fire Service and we will continue this ‘partnership working’ to ensure the safety of our tenants.
We are also issuing valuable guidance to residents which will help reduce the risk of fire within the home. These include;
1. Smoke alarms save lives, please test your alarm regularly.
2. Take extra care in the kitchen and never leave cooking and electrical appliances unattended.
3. Never use a chip pan or any other pan filled with hot oil.
4. Do not overload electric sockets.
5. Keep matches and lighters away from children.
6. Keep clothes well away from heaters and fires.
7. Put out cigarettes properly.
8. Don’t charge things like mobile phones, tablets or e-cigarettes overnight or for longer than required.
9. Plan your escape route.
10. Don’t leave flammable waste in your garden, especially left in close proximity to your house.
I trust this response satisfied your concerns.
Mark Nearney, MSc BA (Hons) MCIOB
Head of Service – Contracts, Investment and Compliance
Adult Care and Housing
Riverside House, Floor 2, Wing C, Main Street, Rotherham, S60 1AE
Mr Nearney said and I quote “If you take a piece of the insulation which is installed as part of the EWI product it is possible to set fire to it”.
The rendered finish is also very easily capable of being knocked or dented etc, and could then expose the (Polystyrene) insulation material, our window cleaner was advised from the contractor to put foam over his ladder ends so he didn’t cause damage to the render.
Also during the work done in some places the insulation didn’t meet, expanding foam was used to fill the gaps, i.e. sometimes around doors, under window sills and to fill old ventilation holes etc.
At the bottom of the damp proof course is an aluminium guard this is first attached to the existing wall. The Insulation then just sits on this no render is applied to it’s underside.
Independent political activist