Calling all Insurers, Loss Adjusters, Claims Professionals! Dealing with Cavity Wall Insulation damaged by the action of an Insured Peril
By Simon Redfearn - Chancery Associates
Damaged Cavity Wall Insulation is rarely dealt with properly and by not doing so do you realise that you are voiding the 25 year Guarantee on the insulation and leaving yourself wide open to action?
A History of Cavity walls and the evolution of retro fit cavity wall insulation
Cavity walls were first introduced on the wind driven rain exposed West and Southwestern coastal areas of the UK in the latter part of the nineteenth century, to prevent wind driven rainfall from penetrating through the solid masonry walls of homes. The traditional cavity wall is built with two skins of brickwork, an inner and an outer leaf separated by a void or air gap (the cavity). These two skins are usually tied together with metal wall ties or brick ties at specific intervals to provide stability to the wall structure. The latter brick or stone ties can allow penetrating dampness and cold bridging across the cavity that can be further exacerbated by retro fitting insulation.
Cavity walls gradually gained popularity and became the preferred method of construction for external load bearing walls across the whole of the UK, because not only did they prevent wind driven rainfall from reaching the internal leaf of the wall, it was also realised that the air gap (cavity) provided a degree of thermal insulation and stopped heat loss through the wall by conduction. In addition the cavity provided ventilation around joist ends and to the subfloor which reduced the build up of dampness from condensation.
Since the 1970’s this insulation quality was further enhanced by the use of lightweight aerated blocks, rather than brick to build the inner leaf of the cavity wall, The primary reason for building cavity walls has always been to keep penetrating wind driven rain, out, a principle that seems to have almost been forgotton in our modern world. To our detriment! You will hear older builders and construction professionals state that ‘that cavity is there for a reason’.
In the 1980’s the UK Building Regulations introduced requirements for new houses to be built with increasing levels of insulation materials within the cavity. Since this time, consecutive governments have encouraged home owners to insulate their homes to save energy and its effect upon our environment.
Building Regulations insist upon cavity wall insulation systems in new build properties. These systems include a clear cavity in addition to the insulation to allow any wind driven rainfall that permeates through the outer leaf to trickle down the internal face of the outer leaf of the cavity wall and this residual cavity prevents the moisture from wetting the insulation and the inner leaf of the cavity.
Successive government initiatives have encouraged the owners of older properties that have cavity walls, to fit cavity wall insulation and there have been grant and incentives made available to the homeowners under various schemes.
Retrofit cavity wall insulation is full fill and is in direct contact with the wet outer leaf of the cavity wall and this is where serious problems can start to occur.
Despite the constant insistence by manufacturers/system designers, the BBA and installers that cavity wall insulation cannot allow rainwater to cross the cavity, the Building Research Establishment has found that it can.
Their findings have been published in BRE Good Building Guide 44: part 2: "Insulating masonry cavity walls - principal risks and guidance"
This states, "There can be an increased risk of rain penetration if a cavity is fully filled with insulation, ie moisture is able to transfer from the outer to the inner leaves resulting in areas of dampness on internal finishes.
Rainwater, under certain driving rain conditions, can penetrate the outer leaf of masonry leading to wetting of the cavity insulation and subsequently cause damage to internal finishes.
Cavity Wall Insulation Systems
Cavity wall insulation is installed as a system. The manufacturer of the insulation is known as a System Designer. It is a requirement of their System Designer Accreditation, issued by the British Board of Agrément, that they approve, train, vet and police the installer that will install their specific system. They will also carry out on-site audits to ensure that the system is being delivered as per the accreditation.
Who are the British Board of Agrément?
The British Board of Agrément was formed on 2 May, 1966 by the Ministry of Public Buildings and Works to assess, test and certify new building products.
Today BBA certification is now respected across the building material supply and construction industry and is symbol of quality and assurance. It is a vital tool for material manufacturers and System Designers to gain credibility for their products and get them specified as the preferred choice by architects, specifiers, building control, local authorities and insurers.
When the BBA approve a specific system they issue an Agrément Certificate on that product.
Agrément Certificates enable a manufacturer’s new product or system to gain quick recognition in its intended marketplace. Only products and systems that have passed a series of robust assessments – including inspections during the production process, quality management auditing, vigorous testing in a laboratory, and on-site testing, are awarded an Agrément Certificate.
Products that have been awarded Agrément Certificates are recognised by local authorities, government departments, architects, specifiers and industry insurers.
When a product or system has received a BBA Agrément certificate, the system is audited at regular intervals to ensure the maintenance of quality and standards, the certificate is fully reviewed every three years.
The install is a complete system of insulation and cannot be repaired, partially re-blown or topped up. It has to be fully removed and re-installed if it is damaged in any way.
The Guarantee
In the region of 6 million homes have been fitted with retro fit cavity wall insulation in the UK and most of these installs are covered by a 25 year guarantee provided by CIGA or Cavity Insulation Guarantee Agency.
There are other Gurantees out there BUFCA GDGC etc, however, the CIGA Guarantee is the most common.
Here is a sample guarantee certificate
Item 2 of the guarantee should be of particular interest to insurers, brokers, loss adjusters and insurance repair professionals.
