As the cost of energy continues to rise, it is becoming more expensive to heat our homes.
Many people are investing in energy saving measures to reduce their heating bills and installing insulation is one of the most popular types of home improvement in the UK.
Properly insulating a house will drastically reduce heat loss, and can save several hundreds of pounds a year on energy bills.
You can insulate the roof of a house by laying insulation in the loft; if you have cavity walls they can be filled with insulation, while solid walls can be insulated from the outside or the inside.
You can insulate under the floor to prevent cold air coming in, and you can also insulate your hot water tank and water pipes to prevent heat being lost to atmosphere.
The type of insulation you use will depend on the area you are insulating and the method of installation.
There are various different kinds of insulation materials; some are suited to a specific application, and others can be used for several different jobs. A guide to some of the more common types of materials used for insulation is below.
Batt or Roll Insulation
Mineral wool is the most common material used for roll insulation. It can be bought by the roll from most DIY shops, and is often used to insulate lofts.
The insulation is unrolled and laid out between the beams in the loft, usually in a double layer. It is ideal for insulation as it is made from recycled materials, and it is fire resistant.
Other materials used include sheep’s wool insulation, fibreglass, cotton, and cellulose fibre. To achieve a U value of 0.25W/m2K, the thickness of roll insulation would need to be anywhere between 150-270mm depending on the materials used.
Rigid insulation boards come in various guises and are typically used for floor and wall insulation. Rigid boards are often used to insulate concrete floors and can be laid underneath or above the concrete. They can also be used to insulate solid walls either using insulation plasterboard for internal wall insulation, or can be used externally.
This type of insulation is very versatile; it can be used to insulate a roof by fixing it to the rafters, and can also be used to increase the thickness of loft insulation.
Some of the types of rigid boards and the materials used to make them include extruded polystyrene (XPS), expanded polystyrene (EPS), polyisocyanurate (PIR), polyiso board, polystyrene bead board, rigid fiberglass, and phenolic foam (PF).
Phenolic foam and polyisocyanurate have the best thermal properties, achieving a U value of 0.25W/m2K at a thickness of 75 – 100mm. Polystyrene based insulation boards require a thickness of 100 – 140mm to meet the same value.
Loose Fill and Blown Insulation
Blown or loose fill insulation is commonly used in lofts and attics, which have poor access, or have irregular shaped beams. If the areas between joists are non-uniform and make it difficult to lay roll insulation, loose fill is an alternative option.
Loose material can be bought by the bag from DIY shops, and poured into the spaces to the required depth. If access is particularly difficult then a professional installer can blow the insulation into the roof space with specialist equipment.
The materials used for loose fill are cellulose fibre, recycled paper, fibreglass, cotton, rock wool, vermiculite and perlite. Loose fill insulation has very good sound-proofing properties and is usually made up of fire resistant material, but will require a thickness of 150 – 260mm to reach a U value of 0.25W/m2K.
Poured or Injected Insulation
This type of insulation is generally used for injecting into cavity walls to increase their thermal efficiency. Several holes are drilled along the length of a wall and the material is injected with special equipment to fill the gap between the inner and outer walls. This type of insulation is usually fitted by a professional installer.
The types of material they would use are polyurethane foams, dense pack cellulose, foamed cement, phenolic foams, tripolymer foams, formaldehyde foams, and magnesium silicate.As a guide to cavity wall insulation, polyurethane foam will achieve a U value of 0.25W/m2K at a thickness of 80 – 100mm.
Spray Applied Insulation
Spray applied insulation can be used for cavity and solid wall applications and can be used to completely air seal areas if necessary. Some types of spray insulation are not suitable for DIY due to the vapour released when spraying, and most of the time this type of insulation is installed by professionals.
Spray applied insulation is ideal for new energy efficient homes but it can be difficult to install, and if it is not done correctly it could prevent proper ventilation of a property.
Polyurethane spray foam insulation and wet spray cellulose are the most common types of spray applied insulation materials. They require a thickness of around 80 – 100mm to achieve a U value of 0.25W/m2K.
If you are insulating your property, whether the walls the roof or the floor, it is worth finding out what the current building regulations are regarding the thermal properties of a home. A U value is a measure of how much heat is lost per square metre, and minimum targets are applied to the U value of floors, walls, windows and roofs.
There are a variety of different materials. which are used in insulation, and the type you use in your home will depend on the type of job you are carrying out.
If a professional installer is fitting the insulation for you, they should ensure that their work complies with building regulations and meets the current standards.
If you are taking a more hands-on approach to the fitting of insulation, you should consider the U value of each type of insulation that could be used for the job. Think about the thickness you will need to install to meet building regulations, and whether this is possible and viable.
You can save hundreds of pounds on your heating bills by installing good insulation, it is important to make sure you use the best materials to get the best results.