Floor insulation is a hot topic right now, along with other ways to insulate your home. Flooring is one of the main areas where heat loss occurs This is due to gaps in floorboards, skirting, and draughts around pipes.
‘Insulating and improving the airtightness of your floor can be a good first step on the road to a cosier home,’ says Chayley Collis at Green Building Store. ‘Ground floors can be incredibly cold, and are a major contribution to the discomfort of inhabitants.’
Insulating your home won’t just make it toasty and warm. It will also help reduce your property’s carbon emissions and lower utility bills. According to the Energy Saving Trust, installing floor insulation in a typical semi-detached house could save you around £50 per year on energy bills. This is as well as 175kg of carbon dioxide.
For thermal performance, you only need to insulate the ground floor of a home. If you live in a flat or upper floor of a maisonette, you usually don’t need to insulate your floor space. However, you should consider insulating any floors that are above unheated spaces, such as garages, as you could be losing a lot of heat through those.
Some people living in older flats or first-floor maisonettes can upgrade the acoustic performance of their floors by using floor insulation. ‘If you want to improve the acoustic performance of your internal floors, make sure the insulation you choose offers acoustic benefits,’ says Bradley Hirst, technical services manager at Knauf Insulation. ‘Mineral wool insulation works well to reduce noise transfer between living areas, bedrooms and bathrooms.’
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Floor insulation is a method of adding materials underneath floorboards if your home has suspended timber flooring. It can also be added on top of a solid floor, such as concrete. The process also involves blocking any draughts by properly sealing gaps in flooring and skirting boards.
‘The insulation materials used will resist the transference of heat and reduce the amount of warmth lost in your home,’ says Thomas Goodman, property and construction expert at MyJobQuote.
According to the Energy Saving Trust, a typical installation could cost you between £520 and £1,300, depending on the circumstances. The initial price may seem steep seeing as the saving is only approximately £50 per year. But it should last the lifetime of your house with very little maintenance cost.
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We take a look at what’s available and pros and cons for each type.
A semi-rigid material, glass mineral wool is made from recycled glass, sand, limestone and soda ash. While rock mineral wool is made from volcanic rock, basalt, dolomite and recycled slag from the steel industry.
Blanket floor insulation is a roll of unfaced mineral glass wool or fibreglass.
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Foam boards are made from foam on the inside and then faced with plastic, aluminium, or plasterboard.
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Foam spray insulation is a liquid foam that is sprayed in between the joists of a suspended timber floor. The foam expands and sets into a superior, insulating layer.
Multifoil is a type of insulation that’s made up of layers of foil as well as wadding.
Draughts happen where there are gaps in the construction of your home, such as floorboards and skirting gaps.
Image credit: Future plc/Dominic Blackmore
A rug on the floor will help you feel warm underfoot and help block up some draughts. But it won’t reduce heat loss through flooring significantly. Carpets can provide a certain level of insulation. To prevent the optimum amount of heat loss you should still install insulation underneath carpets. This ensures your home is protected as much as possible.
Insulating your floors is a good starting point for reducing your home’s carbon emissions, and lowering your utility bills. It will work better when used in tandem with other types of insulation, such as cavity wall insulation and roof and loft insulation. ‘This is known as top and tail insulation,’ says Thomas Goodman. ‘As a rule, the more insulation you have in your home, the warmer and more efficient it will be.’
How much insulation you need will depend on the current U-value of your floor set up. According to the Energy Saving Trust, if you live in England or Wales, the floor should achieve a U-value of 0.25 W/m² K. Less if possible, to meet Building Regulation standards. The U-value is a measure of how quickly heat will travel through the floor. To achieve this standard, the Energy Saving Trust advises installing at least 70mm of high-performance foam insulation, or 150mm of mineral wool. This will vary depending on insulation material and brand chosen, as well as floor type, shape and size.