When insulating a roof, wall or floor, you will soon come across a variety of insulation materials and thicknesses. PIR is a popular choice when a relatively high insulation value is required within a limited build-up. A panel thickness of 100 mm can be used in various constructions, but the right choice depends on the overall insulation assembly and the required performance.

How does PIR insulation work?

PIR is a rigid insulation material that is usually supplied in board form. This makes it suitable for structures where dimensionally stable board material is practical.

The material is used in applications such as roofs, walls and floors. Which panel is suitable depends on the application, finish and properties of the specific product.

Not every PIR panel is therefore interchangeable without further consideration.

When should you choose 100 mm?

The thickness of the insulation, together with the material’s insulating properties, determines a large part of its thermal performance.

A 100 mm layer may be a good option where there is sufficient space available and this thickness is compatible with the desired construction. Whether this is sufficient to achieve a particular level of insulation must be calculated based on the product specifications and the full construction.

Anyone comparing this thickness can look at different types of 100 mm PIR insulation and compare the technical properties with the requirements of the job.

Using PIR for a roof

In roof insulation, PIR can be used in both renovation and new-build constructions. The position of the insulation in relation to the roof structure is important for moisture management.

Vapour barriers, joints and connections must therefore be carefully designed. A well-insulating board has little effect if air flows unchecked through the structure via gaps.

Pay particular attention to connections at walls, beams and skylights.

PIR for walls or floors

Walls and floors can also be insulated with PIR. In the case of walls, available space often plays a major role, for example with a false wall or cavity wall construction.

For floors, the chosen board must be suitable for the relevant structure and load. You should therefore always consult the technical documentation for the specific product.

The same thickness can therefore result in a completely different construction depending on the application.

PIR or another insulation material

PIR is not the only option. Glass wool, rock wool, wood fibre and other materials each have their own properties.

Flexible wool, for example, can work well between irregular wooden studs. Rigid boards, on the other hand, are useful when you want to create a flat, dimensionally stable layer of insulation.

In addition to the insulation value, also consider ease of installation, available space, sound insulation and the existing structure.

Take care when finishing joints and connections

An insulation layer works best when it is installed as continuously as possible. Therefore, measure boards accurately and minimise large gaps.

Depending on the system, joints can be finished with suitable tape or other sealing material. Ensure that connections around pipe penetrations are also neatly sealed.

By planning not only the panel thickness but the entire structure in advance, you’ll ultimately achieve a better-designed insulation system.

Do you have any questions?

At Sleiderink, you’ll find a wide range of building materials, tools and fixings. Do you need advice or want to know which product is best suited to your job? Please contact our customer service team — we’ll be happy to help.