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The benefits of using Phenolic Foam Pipe Insulation

Phenolic Foam is one of the fastest growing insulation products in the UK market today, so we thought it might be worth looking at the comparative benefits of using such products. In this blog we will look at the following areas:

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Thermal Performance
Fire Performance
Moisture Resistance
Environmental Impact

Thermal Performance

When looking at phenolic foam insulation, thermal performance is probably the most obvious place to begin; why? Because phenolic foam is simply better than every other commonly available product, and by quite a distance. Typically phenolic insulation has a thermal conductivity of around 0.021W/m.K at +10ºC, (This is an initial value, the "aged" value is usually more like 0.025W/m.K for a good quality foam) compared to to around 0.032W/m.K for glass wool at the same temperature. Does this make it a better insulation? Yes and no, thermally speaking it is certainly the superior product, but as we always advocate in this blog; you need to use the right insulation for the right application. Phenolic foam is suitable for a wide range of heating and cooling applications, and it has got one decided advantage over certain other insulation products in that its thermal properties do not deteriorate over time, provided that the material remains undamaged. The other decided advantage over other insulation products is that as it is such an efficient product (due to the very fine cell structure) you can usually use a thinner layer of insulation to achieve the same results. This also means the material has a smaller surface area, so if you are using finishing materials such as PIB sheeting or Aluminium Cladding then you do not need to use as much.

Fire Performance

Phenolic Foam has excellent fire performance characteristics. It is difficult to ignite, has either zero or very low flame spread and low smoke emission with a very low level of toxic gas emission. As phenolic foam is a thermoset material it will not run, melt or drip when it comes into contact with a fire source. For this reason it is capable of meeting or exceeding all international building regulation requirements. The toxic gases that are given off by phenolic foam in the event of a fire tend to be limited to either carbon dioxide and carbon monoxide with very low levels of other gases.

Phenolic foam usually achieve a Class 0 Fire Rating to BS476: Parts 6 & 7, and to the new Euroclass Fire Rating should achieve Euroclass B-s1-d0.

Moisture Resistance

Phenolic foam typically has a low water vapour permeance, thus it is highly resistant to the passage of water vapour and it also has very low water absorption characteristics. The material is also "non wicking", this means that if the vapour barrier is punctured and water or moisture that gets in will be limited to the damaged area. This means that you have a measure of damage limitation; you will have to replaced the damaged section, but it will not compromise the system as a whole.

The excellent moisture resistance characteristics make phenolic foam particularly suitable for low temperature hot water, chilled and cold applications.

Environmental Impact

Good quality phenolic foam (such as Kingspan Kooltherm) is both CFC and HCFC free, though some cheaper materials are still manufactured with a HCFC blowing agent. Kooltherm also has an Ozone Depletion Potential of Zero.

To quote the EPFA, phenolic foam has a "low environmental impact per unit of thermal performance compared with many other materials".


At first glance, phenolic foam is amoungt the most expensive materials in the industry, but that is missing they key benefit of the product.

As it is so efficient thermally speaking you can usually use a thickness below to achieve the same results as a mineral fibre product. eg You can often use 15mm Thickness Phenolic where you would have to use 20mm Thickness Mineral Fibre, which is very often the cheaper option. Typically phenolic has a temperature range of -180ºC to +120ºC, so it is not always true that you can simply substitute one for the other - which comes back to the issue of choosing the right insulation for the right application.

Another factor to consider, especially on larger installations, is whether or not you need to use any kind of facing materials on the insulation, such as PIB or Aluminium Cladding. As you can use thinner insulation, the surface area of the insulation will be less, therefore you can use less facing material which in turn saves you more money.

We sell two makes of phenolic pipe insulation: One "Cut from Block" product and the Kingspan Kooltherm product.

The cut from block product is an own brand product that comes at a very competitive price, whilst we also offer the brand leader Kingspan Kooltherm which is very often specified for certain jobs.


  1. Foam for Insulation is exactly what you need to keep your house cold in summers and hot in winters. Phenolic foam can be a bit expensive but its well worth it and will pay for itself within due course of time.

  2. It is really great and nice article and it is informative article. I read this and it is very helpful for me....

    chilled water pipe insulation
    buried pipe insulation

  3. These are actually wonderful some ideas in the blog. You have touched good quality points here. In whatever way continue writing.

    KD Plumbing Auckland

  4. I found this is an informative and interesting post so i think so it is very useful and knowledgeable.

    Flow Fix Plumbing

  5. Your information is really awesome as well as it is very excellent and i got more interesting information from your blog.
    Thermal Insulation Panel


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