Rainscreen cladding in Islington high rise blocks

The Council put out a statement yesterday reassuring people in the aftermath of the awful Grenfell fire:

‘Islington Council always follows the most up to date advice on all aspects of building safety. I am confident that we have good and robust management of our housing stock, including tower blocks. Since 2013 the council has spent £7 million on its fire risk assessment programme and associated fire safety works for all its council housing in the borough, and a further £38million of works is programmed. Any lessons emerging from Grenfell Tower will be acted upon swiftly and comprehensively, as happened following the tragic fire at Lakanal House, Camberwell, in 2009. Where necessary, we will also ensure specifications for future works include any amended advice following the Grenfell Tower fire.

“The Council has a robust Fire Risk Assessment (FRA) programme, with some blocks assessed annually and every block reassessed at least once every three years. Local Area Housing Office staff carry out regular inspections which include fire safety issues. The Council’s fire safety arrangements are also monitored by the Homes and Estates Safety Board, which meets on a quarterly basis and is attended by a member of LFB.’

The council has fire safety advice online for all buildings.  (It’s a little odd to me that the fire safety inspection don’t go into people’s flats given that individual behaviour such as installing downlighters without fire safe cones can lead to awful collective hazard.)

The emerging debate following the tragedy at Grenfell features in part the ‘rain screen cladding’ on the outside of the building.  Commentators and local people suggest that at Grenfell either cladding was combustible itself or the gap between the cladding and the insulation it protects from the rain acted as a flue to amplify and transmit the fire upwards outside the building.

Cladding is one way of insulating elderly concrete buildings with poor thermal performance.  Insulation (such as this)  is screwed to the building, the rainscreen cladding is applied on brackets to stand away from the insulation for drainage and/or condensation.  Intumescent strips are applied horizontally at intervals and around windows: when these get hot they expand and block the condensation gap preventing fire transmission for a period.  This is a similar principle used in fire doors.

Islington council describes the approach it has used:

‘Rainscreen cladding is a form of double-wall construction that uses an outer layer to keep out the rain and an inner layer to provide thermal insulation, prevent excessive air leakage and carry wind loading. The outer layer breathes like a skin while the inner layer reduces energy losses.’

I searched Islington’s planning database for applications to put cladding on tall residential buildings.  This revealed the following three properties with plans for rainscreen cladding (there may be more):

UPDATE – whilst planning was granted these schemes have not yet been implemented – Cllr convery says – ‘We’ve now established that Ilex, Halliday and Gambier have not been clad at all.  Planning permission secured but the projects were not implemented. But there are 3 blocks on Harvist which need closer examination. Plus a couple of blocks which are semi – clad.’

Haliday House, Mildmay Street

‘Constructed in 1970, Haliday House is a 13 storey tower block comprising 73 flats.’

The design statement for the refurbishment and cladding is here.  Detailed pictures of the cladding design are here.  At Haliday Islington proposed using Eternit cladding

Ilex House  Holly Park Estate

‘Constructed in 1972, Ilex House is a 17 storey tower block comprising 97 flats in the Holly Park Estate, off Crouch Hill.’

The design statement contains similar cladding details Equitone is the proposed cladding.

Gambier House

‘Constructed in 1968, Gambier House is a 20 storey tower block comprising of 115 flats. The block is located on a triangular site facing Mora Street, EC1’

The design statement contains similar cladding details.  Equitone Tectiva is proposed cladding.

As far as I can make out the cladding itself has an A2 fire safety rating.

I shared this with Cllr Convery, he said:

‘This is really serious stuff. I’ve looked at the plans Will has identified and it seems we have installed a very similar “rainscreen” thermal cladding system to Grenfell. There’s a group of very similar blocks (Ilex, Harvist x 3 and Halliday). We’ve also put some similar cladding into Brunswick (parts) and Gambier House. I’ve asked the Leader and Diarmaid Ward (Exec member for housing) to very urgently re-assess the fire safety of these overcladded blocks. Whilst we have regular Fire Safety Assessments, I don’t know if these have been included in their methodology or risk assessment the flammability of external cladding which seems to be so clearly the factor at Grenfell. There are a couple of diagrams (pp6-7) of the Gambier design statement which shocked me (see Will’s link above) because they show a ventilation cavity in the sandwich of materials (an external panel, a weather barrier and insulation). The design explicitly excludes any compartmentalisation – because that would be a thermal break. I don’t want to be panicky or grandstand this but I am very worried all of a sudden.’

I am sure that Islington like all owners of tall residential buildings will be scrambling to reassess how residents are kept safe in the light of Grenfell. As will the regulatory authorities.  Once LB Islington has got over that, it would be in the public interest to publish all fire safety reports, to have a full list of Islington buildings that have had rainscreen cladding installed and to learn at what intervals intumescent strips are placed within the cladding to prevent fire transmission and how frequently the strips are inspected.

 

About William Perrin

Active in Kings Cross London and South Oxfordshire, founder of Talk About Local, helping people find a voice online and a trustee of The Indigo Trust , Good Things Foundation and ThreeSixtyGiving as well as Connect8.
This entry was posted in Architecture and tagged . Bookmark the permalink.

One Response to Rainscreen cladding in Islington high rise blocks

  1. Tony Rees says:

    Excellent work Will. Going back to the Ronan Point disaster, all these systems rely on perfect installation and/or an active ingredient such as the intumescent strips in these cladding systems. It seems extraordinary that with the huge potential for tragedy simple fail-safe systems are not mandatory. Why would you rely on the correct installation intumescent strips to protect inflammable panels in order to keep people safe?

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