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Check Insulation Installer & Products are NSAI Certified

  • NSAI warns substandard retrofit insulation is not only detrimental to your home, it can also potentially pose a risk to your health
  • NSAI independently audit, assess and certify insulation building products and installers to ensure they are competent to install the product and the materials are fit for purpose
  • Homeowners advised to follow NSAI’s six step guide, as NSAI certification is not a legal requirement for insulation installers

As the economy continues to grow and more people decide to renovate their homes, the NSAI (National Standards Authority of Ireland) is warning consumers to only use NSAI quality certified products and installers when insulating their properties.

Homeowners have spent over €624 million on renovations and extensions under the Government’s Home Renovation Incentive Scheme since it was introduced in October 2013. That’s €6 million a week spent on doing up properties.

NSAI Certification and Inspection Officer Robin Byrne said he has come across examples of substandard insulation work during his time with NSAI (see photographs below).  He is advising homeowners to only use NSAI quality certified products and installers when trying to achieve a high Building Energy Rating for your home.  Watch as Robin explains NSAI advice on getting your home insulated.

“It’s vital all energy installers, whether for external insulation, roofing and materials, conform to NSAI standards. Substandard retrofit insulation can be hugely detrimental, not only to your property, but it could also potentially pose a risk to your health,” said Robin Byrne, NSAI Certification and Inspection Officer.

“For example, if insufficient ventilation is provided to the home, it can lead to unhealthy living conditions, mould growth, and potentially a build-up of carbon monoxide. Items such as gas and electricity meter boxes and electric cables also require proper attention by the installer. Poor workmanship can also be very expensive to put right, especially in the case of external insulation. That’s why NSAI is encouraging anyone who is considering getting their home insulated this winter, to only use a NSAI registered installer. A full list of registered installers is available on our website” Mr. Byrne added.

By choosing your contractor carefully and following some simple guidelines, having your home insulated can be hugely beneficial, in terms of reduced heating bills, added value to your home and significantly increased comfort. 

NSAI independently assess and certify insulation building products as being fit for purpose and in compliance with the Irish Building Regulations. NSAI certification inspectors also carry out audits on registered insulation installers annually to ensure they are competent to install the product and that they are using the proper materials.

“There is currently no legal requirement for an insulation installer in Ireland to become NSAI certified and the NSAI only has the power to carry out audits on businesses that are certified.  Therefore homeowners need to be careful and do their research,” said NSAI CEO Maurice Buckley.

Radio Interview

  • Certification & Inspection Officer Robin Byrne discusses on The Pat Kenny Show with one homeowner who bared the brunt of substandard insulation.

6 Steps for Homeowners

NSAI recommends the following six steps all homeowners should take before deciding on an insulation contractor:

  1. Check that the contractor is an NSAI registered installer. A full list is available on NSAI website, Registered Installers
  2. Check that ALL products used are certified by NSAI, on Cavity Wall / External Insulation
  3. Check that the contractor is fully insured.
  4. Check that the contractor is registered with Sustainable Energy Authority of Ireland (SEAI) for grant works. It is important that this registration is active; otherwise you could lose eligibility for your grant payment.
  5. Always ask for references and if possible, go see completed projects.
  6. Ask about warranties, verify and READ ALL SMALL PRINT.  Remember that no warranty will be honoured if the insulation system is not installed according to the manufacturer's instructions.

There are 130 NSAI registered external wall insulation installers in the country and 139 NSAI registered full fill cavity wall insulation installers.  A full list of NSAI registered installers and products is available at

Examples of substandard insulation work 

Click on the photographs to open in a new window.  Please note, of the images shown, only pictures 1 and 6 are of work conducted by NSAI registered installers.  The photographs were taken when the site in question was visited following receipt of a customer complaint from the homeowner.

Example 1
The insulation has been installed flush to the gas meter box at the sides, with a small gap left at the top. This is contrary to the requirements issued by Gas Networks Ireland, which require the gas meter box to be temporarily displaced from the wall and then installed on the outside of the finished external wall insulation surface. Some gas meter boxes vent out from the back of the box, and there is a risk of this gas getting behind the insulation boards if the box is kept within the insulation, rather than venting harmlessly into the atmosphere if the box is installed on the outside of the boards.

Example 2
This is a particularly bad example where moisture has affected the insulation causing algae to occur on the wall under the sill, as well as a large fungal growth to occur on the window reveal. 
The sill has rusted which would imply that it was not the appropriate material.

Example 3
The walls were not inspected properly before the cavity insulation was pumped, which resulted in bead entering the property through gaps around the fuse box.

Example 4
This shows poor detailing at the corners of the window. We require ‘L-boards’ to be used at corners, i.e. an insulation board to be cut into an L shape so a continuous piece of insulation is used at the corner, rather than having a weak point or seam where 2 boards meet. This weak point can lead to cracking at that junction, even when stress patches of reinforcement mesh are used.

Example 5
Blistering or delamination of the finish coat, possibly due to being applied in inappropriate conditions, either due to weather or the base coat not being allowed to dry sufficiently before application of the finish coat.

Example 6
External insulation has been installed flush to the electricity box, which has a clear warning sign on it. If that box ever needs to be moved, or even accessed, at a later date, it may result in the insulation being damaged.

Example 7
The flashing details on top of the insulation do not meet and are poorly installed, resulting in gaps which will lead to rain falling directly onto the insulation boards installed on the wall, rather than being protected by the flashings.

Example 8
The concrete oversill installed was not sized correctly or was cut incorrectly, resulting in a significant gap between the back of the oversill and the existing window frame, which the installer has attempted to disguise by filling it with dash.  It should also be noted that this type of sill was not approved for the external insulation system that was installed on this property.

Example 9
The external insulation board is fully blocking the ventilation at the soffit. This ventilation will need to be replicated somewhere on the fascia board to ensure adequate ventilation into the attic space.

Example 10
The flashing under the gutter does not extend all the way to the end of the wall, resulting in moisture falling directly onto the insulation board. Dampness can be seen on the external face of the insulation at this point, and blistering/delamination of the finish coat.

Example 11
A vertical fire barrier of non-combustible material should have been installed at the party wall junction of the property insulated and the neighbour’s uninsulated property. In this case, such a fire break was not installed as the graphite enhanced EPS board is visible rather than a lamella board.

The insulation at this junction is exposed, which could lead to moisture getting behind the boards, which in extreme cases can lead to blow-out of the boards. The ends of insulation at junctions like this must be coated and appropriately sealed.

Example 12
There is a gap between the existing window frame and the bead used to form a waterproof seal to prevent moisture from getting behind the insulation.