Celotex Isover


Here is a page dedicated to questions frequently asked by our customers.

U-value Calculator
Start your U-value calculation >
Use the calculator

Filter by category or search for what you need to know

Can ISOVER CWS be used below DPC level in masonry cavity walls?

ISOVER CWS is manufactured with a water-repellent binder, meaning that it can safely be used below DPC level in masonry cavity walls without the risk of ground moisture bridging the DPC via capillary action.

Can ISOVER Spacesaver be used in a sloped or vertical application?

ISOVER Spacesaver is a low-density loft insulation roll, and as such we would only recommend it be used in a horizontal application as it may not self-support in any sloped or vertical application.

Do I need to use membranes when installing PIR below a concrete slab or screed?

First of all, ensure that the PIR insulation boards are laid above the damp proof membrane (DPM). The foil facings of our PIR insulation boards may be damaged by wet screed or wet concrete, allowing gas to escape that may weaken the floor topping so we would always recommend a membrane be used for protection over the PIR insulation boards once they have been laid & prior to the screed or concrete topping being poured.

Do I need to wear PPE when installing your insulation products?

Our safety data sheets provide information on the precautions that should be taken when installing our MW or PIR insulation products.

Does your insulation attract rodents or other vermin?

Our insulation offers zero nutritional value to vermin, although if rodents can access the insulation they may use it as a nest.

How should PIR products be stored?

Our PIR insulation boards should be stored in their original packaging, protected from the weather and clear of the ground. Any damaged boards (e.g. crushed corners) or wet boards should not be used.

For any further queries please contact our Technical Support Centre

Once installed, how long will your insulation last in my building?

Once installed, if left unmolested and undisturbed we can say that the insulation will perform for the expected lifespan of the building into which it is installed, which is generally taken to be 60 years.

What is a Euroclass ‘reaction to fire’ rating?

A Euroclass ‘reaction to fire’ rating is a measure of a product’s behaviour when exposed to a direct ignition source. The behaviour is classified as A1 through to F, with A1 attaining the highest level of performance and F the lowest level of performance.

What is the best way to cut Mineral Wool or PIR insulation?

Specialist insulation saws and knives are widely available, these should be used to trim or cut our insulation products when required.

Where can I find the Declaration of Performance (DoP) for your insulation products?

Visit our webpage dedicated to our Declarations of Performance to download the appropriate DoP for your product, or alternatively look for a link on the relevant Product Page.

We’d like to make finding the answers to your questions as simple as possible, and want to help you use our website with ease.

Take a look at our collection of questions. If your query cannot be answered on this page, please contact the Technical Support Centre on 01473 820850

Can't find what you're looking for? Contact us with your query Calculator Icon