Skip to main content
Back to articles

Celotex vs Kingspan: What’s the Difference?

When looking at insulation there has long been debate surrounding Celotex vs Kingspan. Both offer polyisocyanurate (PIR) based solutions. PIR is one of the most thermally efficient of all insulation materials used in construction. Celotex and Kingspan both realised the benefits of this material and have built reputable brands around it.

Whether you are looking at Celotex insulation boards or Kingspan insulation boards, you need to ensure that you are getting value for money and that you are using the best possible materials. As these are both big names in the industry, many find it difficult to choose between the two and many struggle to see if there are any differences at all.

We’re here to help. Read on so that the next time you are faced with the choice between Celotex or Kingspan, you’ll be fully informed and know exactly what to expect from the two.

Celotex vs Kingspan – a brief look back

When looking at Celotex UK, the name is synonymous with PIR insulation. In fact, many people routinely use the name not realising that it is actually a brand. In much the same way that the term Hoover is used to refer to vacuum cleaners as a whole, Celotex has become a generic term. The truth though is that Celotex is one of the biggest names in the industry. It has been producing high quality insulation boards for over 90 years.

As a direct comparison, Kingspan is a relative newcomer. That being said, it has still been around for over 50 years! In that time it has built a solid reputation and is renowned for the quality of the insulation boards that it produces.

Celotex or Kingspan – what’s the real difference?

When trying to decide between Celotex or Kingspan your decision will be based on the exact product that you need. Both Kingspan insulation boards and Celotex insulation boards are made from PIR and so, as you would expect, these products are fairly similar:

Celotex XR4000/ GA4000/ TB4000

  • Surface – composite foil facing
  • Thickness – 100mm
  • Length x width – 2400 x 1200
  • Use – multipurpose
  • Thermal conductivity – 0.022 W/mk
  • Compressive strength – 140 kPa
  • Thermal resistance – 4.5 m2K/w

Kingspan TF70/ TW55/ TP10

  • Surface – composite foil facing
  • Thickness – 100mm
  • Length x width – 2400 x 1200
  • Use – multipurpose
  • Thermal conductivity – 0.022 W/mk
  • Compressive strength – 140 kPa
  • Thermal resistance – 4.5 m2K/w

As you can see, when you look at the spec of the PIR insulation, there is literally nothing to choose between the two. They both come with the same specifications and really the choice comes down to the name that you want to side with. In terms of installing and working with Celotex insulation boards and Kingspan insulation boards, there are no differences at all, or certainly none of any note.

Celotex Thermal Conductivity vs Kingspan

When looking at any insulation, the thermal conductivity is significant when trying to decide on the best one to use. Looking at the Celotex thermal conductivity value is an important part of comparing this brand to Kingspan. First, though, it’s worth being clear on exactly what thermal conductivity is.

Thermal conductivity is a measure of how well a certain material conducts heat. The purpose of insulation is to retain heat within the building structure, and therefore NOT conduct heat. This means that when it comes to insulation, the lower the thermal conductivity value the more thermally efficient the insulation. Thermal conductivity is measured in Watts per metre Kelvin (W/mK for short), where the lower the value the better.

Looking at Celotex and Kingspan PIR insulation, both have a thermal conductivity value of 0.022 W/mK (this is the same for all UK PIR manufacturers). This means that they are equal in terms of thermal efficiency, and although there are different names on the boards, they both perform the same in terms of heat retention.

The Kingspan Kooltherm range

When looking at Celotex vs Kingspan, so far we have considered like for like comparisons by only looking at the PIR range. As far as Celotex UK goes, this is the extent of what they offer in terms of insulation boards and, as we have seen, the quality and usefulness are very much on a par with the PIR offering from Kingspan. Kingspan insulation boards, however, also come in another range called Kooltherm.

The Kingspan Kooltherm insulation boards are made from a fibre-free, rigid, phenolic core (rather than polyisocyanurate). This allows the boards to achieve lower thermal conductivity values than PIR insulation, with certain boards within the range achieving as low as 0.018 W/mK. This makes the Kooltherm range the most thermally efficient insulation solution available in the UK, coming up trumps when compared to Celotex. However, whilst most PIR insulation is priced at a similar level, you will pay a premium for Kooltherm insulation, so it’s sensible to only use it if it’s been specified by an architect.

Should I choose Celotex or Kingspan?

As we have seen, if you are looking at PIR insulation then there is nothing to choose between. Whether you opt for Celotex or Kingspan you are pretty much getting the same product that offers the same level of performance. You will likely find that Celotex and other PIR brands are cheaper than Kingspan, despite the fact that the products are basically identical. The only real differences come into play if you decide to explore the Kooltherm range from Kingspan.

The Kooltherm range is far superior to Kingspan’s own PIR insulation as well as Celotex insulation boards. Being made of material that is more thermally efficient, the Kooltherm range from Kingspan outperforms anything that has been produced by Celotex.

If you are looking for a company that understands all that there is to know about insulation and one that can bring you the supplies that you need, why not take a look at the range that we have on offer. If you need any help or guidance, get in touch today and let us show you why we’re the first choice when it comes to insulation supplies.

Back to articles