Celotex vs Kingspan – Which insulation is better?

Both Celotex and Kingspan are popular types of insulation available in the UK. Both offer a range of products, for insulating different areas of a property. Their most common products are polyisocyanurate (PIR) insulation boards. However, Kingspan also offers another type of rigid insulation known as Kooltherm. This is a premium product made using a phenolic foam and is considered an upgrade from PIR.

The standard type of PIR insulation board is easy to cut and install in a variety of areas. In this article, we will briefly look at Celotex vs Kingspan, to determine if there are any major differences between each brand of insulation, and whether one brand is better than the other.

celotex vs kingspan

Celotex vs Kingspan product range

Both of these brands offer a similar range of products. However, there are some differences. Both offer PIR insulation boards. These come in a range of dimensions, which offer quite similar thermal values based on their thickness.

They also both produce insulated plasterboards which again are quite similar in terms of performance.

However, Kingspan also offer several other products. These include:

  • Kooltherm insulation boards – This is a high-performance insulation material made from phenolic foam. This material has lower thermal conductivity than standard PIR insulation products.

    When looking at products of the same thickness, phenolic foam will provide around 19% improvement in thermal conductivity. As a result, thinner boards can be used to achieve the same level of insulation. With that said, they are considerably more expensive than PIR.

  • Insulated wall and roof panelling – These are panels that are commonly used in commercial, industrial, and retail buildings. The panels consist of Kingspan’s proprietary QuadCore insulation material, sandwiched between two layers of metal cladding. This usually has a smooth surface for walls and a corrugated finish for roofing applications.

  • K-Roc Framing Slab – This is a type of rock mineral slab. It is primarily used with metal framing systems.

Kingspan also offer several other products which can be seen on their website here. Therefore when comparing Celotex vs Kingspan based on their range of products, Kingspan does win. However, for standard PIR insulation, both companies do offer very similar products. Both provide very similar thermal performance and cutting and installing is almost exactly the same.

Kingspan vs Celotex price comparison

If you are just looking for a standard PIR insulation, then both of these brands can offer a similar quality of product. This means that your final decision will often boil down to price.

As a general rule, Kingspan does tend to be more expensive per m2. However, the price you pay can vary widely based on the supplier. This can be affected by your location in the country, but it can also be quite different from one local provider to another.

A good example of this, would be buying from a large DIY store, such as B&Q, or Wickes, vs buying from a builder’s merchant. The latter will usually be significantly cheaper. You may also get even better deals when you buy larger amounts.

The key to getting the best price is shopping around. You will often be surprised by how much prices can vary even between more competitive builders’ merchants.

With that said, if we were to compare average prices, Kingspan would usually be the most expensive. As a rule of thumb, you can expect to pay 10-20% more for a like-for-like Kingspan insulation product vs Celotex.

If you are choosing a more premium product such as Kooltherm, this number could be significantly higher, and it would be quite common to pay 50% more compared with a standard PIR product.

Based on average prices, Celotex wins and in the vast majority of cases it will be the cheaper option. With that said, you should always shop around. There are deals out there and you may occasionally find suppliers where Kingspan ends up being the cheaper option.

Availability of Kingspan and Celotex

Both Celotex and Kingspan are popular well-known brands. As a result, they are stocked throughout the UK and have wide availability. They are also widely available online, which means you can easily order via suppliers’ websites and have products delivered.

Locally the availability will depend on the supplier, but both will usually be available when you shop around.

One other thing that can affect availability, is the specific product type and thickness. There are less-common products that may not be as widely available. In this case you may need to order online.

It is also worth noting, that these are not the only brands available. You will also find other brands that have similar products, especially when it comes to standard PIR insulation.

As a general rule, these will have very similar thermal performance when compared with like-for-like products.


In conclusion, when we compare Celotex vs Kingspan, they are very similar types of insulation. However, each has its own range of products and there are some differences. The exact type, size and thickness of insulation will depend on what it is being used for.

When it comes to the most commonly used types of rigid insulation, both brands are very close in terms of performance. For example 100mm of PIR insulation from Kingspan and Celotex will provide very similar thermal performance (if not identical).

Often your final decision will come down to cost, and in most cases Celotex will be the cheaper option.