Like most things in construction, thermal insulation needs to be done right in the first attempt, or not at all. This not only means exemplary workmanship but also choosing the right types of products and installing them in the correct configurations for the intended premises or room. Many thermal solutions are available on the UK market today. Some are used on their own, while others perform better in combination with other insulative materials.  

The upfront costs are minimal when compared to the savings in energy bills. With less heat penetrating walls in the summer, you won’t be running up the kilowatts from the AC to maintain decent levels of comfort. The same goes for the colder months when thermal products keep warm air in. In fact, the majority of your energy bills goes towards heating and cooling.  

Thermal insulation also helps in structural rigidity. The different boards and fibres support adjoining frames and walls. They also prevent deterioration or decay in wood from moisture, mould or pest infestations.  

Types of Thermal Insulation 

To insulate any part of a residential, commercial or industrial building, builders and renovators have a wide range of products on offer. For better heating, cooling and overall interior comfort thermal insulators are used. Here too there is diversity. Products differ in their insulation efficiency (or what in the industry is called the R-value), the ease of installation and the environmental impact that goes in their production. Also, varying levels of fire resistance will mean higher prices.  

Mineral Wool and Cellulose 

Mineral wool comes in a few varieties including rock wool, slag wool and glass wool. These are environmentally friendly insulation products made from waste in industrial processes. Rock wool is a by-product of steel production and consists of basalt, blast furnace slag and limestone. Slag wool is similar, made mainly of steel slag and natural rock. Fibreglass or glass wool consists of compacted scrap glass fibres, connected by a binder. Mineral wool is sold in pre-cut rolls in different lengths and thicknesses or is applied as a loose material. It is affordable and easily installed. With a high R-value, good moisture and fire resistance, and high acoustic absorption, it is widely used in roofing, cavity and curtain walls, ducting and ceilings.  

Cellulose is made of fibres from recycled paper, with the addition of a flame retardant, making it both eco-friendly and resistant to very high temperatures. Though a low-cost option, with good moisture, mould and acoustic resistance, it needs more work and attention during installation. 

Thermal Insulation Boards 

The most common materials used in thermal insulation boards are polyurethane and polyisocyanurate. This lends to PUR and PIR thermal insulated plasterboard. The boards are similar in composition, with PIR boards consisting of a modified and improved polyurethane mix, to produce rigid closed-cell foam bubbles. Both board types are lightweight and produced from recyclable materials. PIR boards are much better in terms of the environment. 

PIR, also known as ISO or Polyiso, builds on the excellent insulative qualities of PUR boards in that it has a higher R-value. In fact, PIR thermal insulation boards have some of the highest thermal efficiency of any insulation materials currently on the market, almost twice as much as various mineral wools, and 10-15 per cent more than PUR thermal boards. This makes them the best option for very high resistance to fires. In addition, thinner boards can be used to achieve similar insulation levels when compared to other materials, meaning lower cost. 

The thermal properties of PIR thermal boards are further enhanced by the facer and backer materials. PIR boards are often recognisable by the aluminium foil, which eliminates so-called “thermal bridges” or drafts of cold air. Similarly, boards can have mineral glass foils in the facer for improved resistance to moisture and humidity.  

Polyiso boards are sold in different sizes, ranging from a relatively thin 20mm and all the way up to 150 mm thickness. Standard heights of 2400mm and widths of 1200mm are sold by various brands, making them ideal for a variety of applications. Boards are easily cut and fitted to the required shape. Those with higher thicknesses and facer and backer materials will provide better thermal insulation. All PIR thermal boards comply with current UK construction standards.

Uses of PIR Thermal Board 

PIR boards are a type of rigid board and lend structural strength to the applied area. Aluminium faced PIR boards are extensively used in internal cavity wall insulation, in sheathing areas between steel or timber frames. Individual boards are interlocked in larger sections by use of adhesives and PVC or duct tape to further reduce gaping. Boards with mineral wool coatings are used where moisture resistance is vital. This includes insulation of slanted and flat roofing.  

Versatility doesn’t end there. PIR thermal boards can be bonded to various surface materials. Boards bonded to plywood and OSB board provide superior thermal insulation in flooring of all types. PIR boards can also be used in combination with plasterboard in all wall applications. This not only means better thermal insulation but also better soundproofing.  

Benefits of PIR Thermal Insulation Boards 

PIR thermal boards are steadily replacing PUR boards for all insulation purposes. It has better thermal management, without the added costs. When compared to traditional polystyrene-based boards, like Expanded polystyrene or EPS, and extruded polystyrene or XPS, the benefits are more obvious. Not only do PIR boards have twice as much thermal resistance, or R-value, but they are not combustible, unlike polystyrene. Polyiso boards can withstand temperature extremes ranging from -75°C to +125°C. This is partly due to better facer materials, which besides high temperatures are also resistant to chemical solvents, making PIR thermal boards ideal for industrial applications.  

Because of its inherent rigidity, PIR insulation won’t deform during the whole service life of the structure. Boards are easier to shape and cut to the desired sizes and don’t require the use of special PPE gear, unlike some mineral wools. It is also an environmentally friendly option, developed as an alternative to the ozone-depleting CFCs in PUR and XPS thermal boards.  

PIR thermal insulation boards are sold in the standard sizes and thickness in all good stores stocking construction and insulation materials.