What Is Insulated Plasterboard?

Insulated plasterboard is a 2-in-1 insulating and drylining board that has been designed to provide insulation and plasterboard in one solution. It is often used in places where there is a need to keep the heat in, such as homes with lofts that are used for living space or in commercial properties.

It is made up of two layers; one layer of standard wallboard plasterboard – usually 12.5mm or 9.5mm – and a layer of insulation board – usually PIR insulation or polystyrene insulation – that are then bonded together.

There are several benefits to using insulated plasterboard over standard plasterboard or insulation board on their own. Firstly, it can help to keep the building warm in winter and cool in summer, making it more energy-efficient. This is something that plasterboard on its own will not accomplish. It is also easier and quicker to install than installing the individual components separately. With insulated plasterboard, you can just bond it to the masonry wall using plasterboard adhesive, and then skim over the plasterboard with multifinish plaster.

Types of Insulated Plasterboard

There are three main types of insulated plasterboard:

• EPS insulated plasterboard – such as Thermal Basic Insulated Plasterboard
• PIR insulated plasterboard – such as Celotex Insulated Plasterboard
• Phenolic insulated plasterboard – such as Kingspan K118 insulated plasterboard

These range in thermal efficiency from not very efficient (EPS insulated plasterboard) to extremely efficient (phenolic insulated plasterboard). Although the installation method for each type of insulated plasterboard is very similar, the type of insulated plasterboard you choose will be dependent on the thermal requirements and specification of the application.

Thicknesses of Insulated Plasterboard

When choosing insulated plasterboard, it is important to consider the thickness that you need for the job.

The thicknesses of insulated plasterboard can be a little confusing at first, because they refer to the overall thickness of the insulation board AND the plasterboard bonded together. For example, Celotex insulated plasterboards offer thicknesses of 37.5mm, 52.5mm, 62.5mm, and 72.5mm, where 37.5mm refers to a 25mm Celotex PIR board bonded to a 12.5mm Wallboard. In this instance, a 12.5mm plasterboard is bonded to various thicknesses of PIR insulation. This is the same for Phenolic insulated plasterboard, where a 12.5mm plasterboard is bonded to various thicknesses of Kingspan Kooltherm Phenolic Insulation.

For EPS insulated plasterboard, a 9.5mm plasterboard is used instead of a 12.5mm plasterboard. This gives thicknesses of 22mm, 30mm and 40mm. Although in reality these thicknesses have been rounded up by 0.5mm to the nearest full millimetre, they are always referred to as these thicknesses rather than .5mm like their PIR cousins (welcome to the construction industry!).

When Would You Use Insulated Plasterboard?

There are a few situations where it would be beneficial to use insulated plasterboard over standard plasterboard.

If you are looking to convert your loft into a living space then insulated plasterboard can help to keep the area warm in winter and cool in summer, making it more comfortable to live in.

The lining of walls is another common application for insulated plasterboard. This is often done in homes and commercial buildings to help with the thermal efficiency of the property. Insulated plasterboard can also be used in ceilings too.

Like standard plasterboard, you can directly paint or wallpaper over insulated plasterboard once it has been installed.

How to Cut and Install Insulated Plasterboard

Insulated plasterboard is generally harder to cut and install than standard plasterboard. This is because it is thicker and can be more difficult to handle. However, there are a few tips that you can follow to make the process easier.

Firstly, use a sharp blade when cutting the plasterboard. A blunt blade can cause the board to chip and break. Secondly, always use a straight edge when cutting, as this will help to ensure that the cuts are straight. Thirdly, use a spirit level when fitting the plasterboard to make sure it is level.

If you are unsure about how to cut and install insulated plasterboard, then it is always best to consult a professional.

If you are thinking about purchasing insulated plasterboard, you can see our full insulated plasterboard range and PIR insulated plasterboard range, or check out some of the top-selling manufacturers, such as Celotex and Kingspan.

Alternatively, reach out to our team and they will be able to help you select the best product for your application or project.