Frequently Asked Questions

Rigid polyisocyanurate (PIR) boards are widely used in the construction industry to provide technically advanced thermal insulation solutions. Specifying the right board for the application is vital to meet today’s increasingly stringent building regulations.

EcoTherm’s Technical Team provides answers to some frequently asked questions about selection and installing insulation.

Unfortunately, there is no one simple answer to this question as it really depends on various key factors. Firstly, there’s the matter of where the insulation is going to be used in the building envelope, for example in a cavity wall or in a pitched or flat roof. You also need to consider which other building materials form part of this particular element (i.e. brickwork / blockwork in a wall, or tiles and plasterboard in a roof).  Cavity spaces will also have an effect on the insulation thickness. At EcoTherm®, our technical team is always happy to advise on this important aspect of specification.

Typically for floors, we would recommend using a board that exceeds 140KPa when tested to BS EN 826: 1996, our Eco-Versal boards are ideal for this application.

At a time when there is a universal call for increased effort to protect the environment, it’s important to check that the insulation boards you buy are manufactured from CFC and HCFC free grades of raw materials which ensure zero Ozone Depletion Potential (Zero ODP). EcoTherm® boards possess both of these qualities and also have a low Global Warming Potential (GWP).  

Additionally, EcoTherm holds ISO14001 certification, as do our two main raw material suppliers enabling increased credits for a BREEAM assessment.

Insulation itself does not have a specific U-value, as this is based on the different building construction elements i.e. wall, floor or roof.

Call us to determine the correct thickness of EcoTherm insulation to achieve your target U-value that complies with Building Regulations.  We will then produce a U-value calculation for you (including condensation risk analysis if required) to show your Building Control Officer that you comply.

They can be cut with a sharp knife or a fine toothed saw. As a responsible company, we recommend that users take a sensible approach to the cutting of boards with strict regard for health, safety and environmental standards.  Eye protection should be worn when cutting boards.  Cutting with power tools generates dust so should be kept to a minimum.  Operations which produce dust should be carried out in well ventilated conditions and where possible an appropriate dust mask should be worn.
For our boards, we recommend that for a long duration of extreme temperatures then -50°C to +110°C are not exceeded.
If the PIR board has been correctly applied then it has an indefinite life and will deliver design insulation values for the lifetime of the building.  However this does, of course, depend upon the method of application, supporting structure and conditions of use.

Yes, and EcoTherm Eco-Versal is ideal for this application. We recommend placing a sheet of polythene (1000 gauge / 0.25 mm) over the insulation before pouring your screed. This will protect the foil surface of the insulation from the alkalinity / dampness of the screed and prevents it entering the joints between the boards.

Possibly - if external wall insulation is being considered, you should contact the render manufacturer for recommendations on what insulation products are approved for the system.
Dry your boards before using them by natural means only. Do not use direct heat, such as a naked flame to dry the boards. Do not lay the boards in temperatures of less than 5°C as condensation may occur. If work is interrupted, the laid boards must be protected to prevent water penetration. Store the boards in a flat, dry area clear off the ground and away from sources of mechanical damage or ignition.  Boards should be completely covered with waterproof sheeting if stored outside.
EcoTherm PIR insulation boards are rigid in nature and a closed cell material, meaning water absorption is minimised.

The Department for Communities and Local Government (CLG) recommend the use of closed cell insulation materials in their guidance document “Improving the Flood Performance of New Buildings” due to the materials' ability to recover from the effects of water immersion and to return to the expected level of thermal performance as soon as possible after the water has subsided:

Wall Insulation: "Cavity insulation should preferably incorporate rigid closed cell materials as these retain integrity and have low moisture take-up. Other common types, such as mineral fibre batts, are not generally recommended as they can remain wet several months after exposure to flood water which slows down the wall drying process. Blown-in insulation can slump due to excessive moisture uptake, and some types can retain high levels of moisture for long periods of time (under natural drying conditions)."

Floor Insulation: "Water will lower the insulation properties of some insulation materials. Floor insulation should be of the closed-cell type to minimise the impact of flood water...It is recommended that insulation be placed above the floor slab (and underneath the floor finish) rather than below would minimise the effect of flood water on the insulation properties and be more easily replaced, if needed."

The full CLG guidance document can be downloaded at
If electrical cables are installed in contact with the insulation there should be no detrimental effect to the PVC coatings of the cables, whereas other types of insulation may cause issues.  Always consult a qualified electrician when any electrical work is to be carried out.

More questions?

For advice on any aspect of choosing and using our boards, get in touch with our Technical team

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