Choosing the best insulation for you can make a difference to the long-term performance, efficiency and value of any project. Both PIR and EPS insulation boards are common insulation products in the UK.
Each product has its place. They are designed for similar applications but offer different levels of thermal performance. All projects must meet the UK Building Regulations. PIR insulation boards are often the preferred product, as they can meet the required criteria due to their insulation properties, thinner structure and durability.
At Trade Insulations, we specialise in supplying a range of PIR insulation boards from some of the most popular brands, including Celotex, Soprema and Kingspan. We help contractors, builders and homeowners find some of the best prices around.
In this guide, we compare PIR insulation boards and EPS, explain the benefits of each and answer the big question – why is EPS becoming unpopular?
What Are PIR Insulation Boards?
PIR boards are rigid insulation boards designed to offer excellent thermal performance. This makes them popular products, as they can provide strong thermal performance at a reduced thickness and take up less space than alternative products.
PIR insulation boards can be fitted in:
- Flooring
- Roofs
- Loft conversions
- Timber frames
- Cavity walls
- Solid wall insulation
- Garden buildings
- Commercial developments
One of the main reasons builders choose to use PIR insulation is its thermal efficiency. Many PIR boards have a thermal conductivity of 0.022 W/mK, helping projects meet the requirements of the UK’s current Building Regulations.
Why We Specialise in PIR Insulation Boards
At Trade Insulations, PIR boards are one of our core product ranges.
We stock popular brands such as:
- Celotex
- Kingspan
- Soprema
- Recticel
- Mannok
- Ecotherm
Alongside PIR boards, we also supply a variety of plasterboards, loft rolls, fixings and accessories. We focus on supplying our customers with quality products at competitive prices, helping them source the materials required for their projects.
What Is EPS Insulation?
EPS stands for Expanded Polystyrene.
It is made by expanding polystyrene beads and compressing them. As EPS is relatively cheap to produce, it has been used over the years for applications such as floor insulation, slabs, external wall insulation and filling.
EPS remains popular for budget-restricted projects where the thickness of the insulation may be less important. However, compared with PIR insulation, its thermal performance is significantly lower.
For projects where the thickness of the product matters, PIR is often the preferred choice.
EPS vs PIR Boards – Thermal Performance
When comparing the thermal performance of both products, PIR insulation boards have an advantage over EPS.
Most PIR boards have a thermal conductivity of 0.022 W/mK, whereas EPS typically has a thermal conductivity of between 0.030 and 0.038 W/mK. Overall, PIR performs up to 68% better than EPS.
The difference between the two can have a significant impact. Generally, a lower thermal conductivity means that the insulation provides better thermal performance. This can allow builders to achieve the same U-value by using a thinner board, such as PIR.
What Are the Benefits of an Insulation Board’s Thickness?
One of the biggest advantages of a PIR board is its reduced thickness. To achieve a good level of thermal performance, you may only need to use an 80mm PIR board. In comparison, you may need a 140mm EPS board to achieve the same rating. This is a specific example, but the principle applies across different board thicknesses.
The additional 60mm of EPS can make a difference when insulating a project, as every millimetre saved enables more space to be utilised. This can be applicable to projects of all sizes.
Why Do Builders Prefer to Work With PIR Insulation Boards?
Across the industry, PIR is a popular product to work with.
This is due to its many benefits, which include:
- Thermal efficiency
- Compliance with regulations
- Reduced build-up
- Lower heating costs
- Better long-term energy efficiency
- Compressive strength
- Moisture resistance
- Can be cut to size
- Cost-effective
These benefits make PIR boards particularly popular with contractors and for housing developments.
Is EPS Becoming an Obsolete Product?
This is a question that is circulating in the construction industry and one that does not yet have a clear answer. We believe it could become obsolete over time, mostly due to its decreasing popularity, but also because it is not considered environmentally friendly.
Although it still has its uses, EPS has decreased in popularity as building standards have continued to improve.
Modern Building Regulations require:
- High U-values
- Thin wall systems
- High energy efficiency levels
- High thermal performance
These requirements tend to favour PIR insulation. As regulations become stricter, many contractors are likely to specify PIR boards rather than EPS.
It is likely that EPS will continue to be available, but it does seem to be falling out of favour with builders working on current developments across the UK. At Trade Insulations, we sell both EPS and PIR insulation boards, but for how much longer, we cannot say.
Which Projects Benefit Most From Using PIR?
PIR boards are commonly used on:
- New housing developments
- Loft conversions
- Roofing
- Internal walls
- Timber frames
- Garden buildings
This is because these projects can benefit from using less insulation thickness where making the most of the available space is a priority.
The Long-Term Value vs Initial Cost
EPS will generally be cheaper initially. That said, construction decisions should not always be based solely on the price of the materials.
PIR can often provide better long-term value, as it can help projects meet regulations, reduce heat loss and improve the energy efficiency of a build. Many builders view PIR products as an investment due to their long-term benefits.
Frequently Asked Questions
Is PIR Insulation Better Than EPS?
For most projects, we would recommend using PIR boards due to their excellent thermal performance and reduced thickness.
Is EPS Cheaper Than PIR?
Yes, EPS is cheaper than PIR. However, you will generally need to use thicker EPS boards to achieve the same R-value that a PIR board would provide.
When Comparing EPS and PIR, Which Board Will Last Longer?
Both offer good longevity if they are fitted correctly. However, PIR can offer more consistent performance.
Why Are More Developments Using PIR?
PIR is increasing in use because it delivers excellent thermal performance while taking up less space. This can help projects meet the Building Regulations in the UK.
Does Trade Insulations Sell EPS?
Yes, Trade Insulations does sell EPS. We specialise in offering premium PIR insulation boards and other high-performing insulation products, including EPS from leading manufacturers.
Which Brands Does Trade Insulations Stock?
We stock some of the most popular brands, including Celotex, Kingspan, Recticel, Soprema, Knauf and many more.
Both PIR and EPS have their uses. However, there is more evidence showing the benefits of using PIR insulation boards. They offer excellent thermal performance, a thinner profile and can help projects meet the UK Building Regulations. This makes it easy to see why they are currently a popular product for builders, contractors and homeowners across the UK.
EPS is still used for budget-friendly projects, particularly flooring or lower-specification projects. However, energy efficiency and space-saving in construction are increasing priorities. Therefore, PIR boards are more likely to remain a popular choice.
At Trade Insulations, we are committed to supplying high-performance products from the UK’s leading brands. Whether you are insulating an extension, commercial development or new-build project, we have products available to help you meet the Building Regulations necessary for your application.
