What You Need to Know About Underfloor Heating
Underfloor heating is neat, efficient and deliciously toe-warming, but which system is right for you and your flooring?
Sophie Baylis
17 November 2018
Houzz UK Contributor: I'm a London-based freelance journalist with many years of experience writing about interiors for leading magazines in the UK and overseas. Follow me at @InteriorsInOut on Facebook and Twitter.
Houzz UK Contributor: I'm a London-based freelance journalist with many years of... More
Comfort, efficiency, not to mention the freedom to design a room without having to work around radiators… These are just some of the reasons more of us are investing in underfloor heating. And in the often chilly British weather, what could be more tempting than the idea of cosy toes as you step out of bed in the morning?
The good news is that underfloor heating is suitable for all types of projects, from new builds to retrofits and refurbishments, and can adapt to suit many different types of flooring. There are two types of underfloor heating systems to choose from. To ensure you invest in the right one for your home, read this advice from three of the UK’s leading underfloor heating experts.
Professional advice from: Joan Pask of Warmup Plc; Steven Rooney of Gaia Climate Solutions; Gerald Stow of GS Underfloor Heating Systems
This article is from our Most Popular stories file
The good news is that underfloor heating is suitable for all types of projects, from new builds to retrofits and refurbishments, and can adapt to suit many different types of flooring. There are two types of underfloor heating systems to choose from. To ensure you invest in the right one for your home, read this advice from three of the UK’s leading underfloor heating experts.
Professional advice from: Joan Pask of Warmup Plc; Steven Rooney of Gaia Climate Solutions; Gerald Stow of GS Underfloor Heating Systems
This article is from our Most Popular stories file
Why choose underfloor heating over radiators?
One significant pro is that it can be much more energy efficient – especially a water-based system (more on which shortly). ‘It works at a lower temperature [than radiators] and will also contain heat for several hours in the floor once it reaches the optimum temperature,’ explains Gerald Stow. All types of underfloor heating also provide a much more even spread of heat than a radiator.
On the downside, initial installation is typically more expensive than a standard central heating system. It can also be less sensitive than radiators, which heat up swiftly once turned on and cool down rapidly (though electric underfloor heating systems usually heat up more quickly than water-based ones, but can be more costly to run).
However, clever use of the timer and thermostats, and even a weather sensor, can all help to manage this issue, so ask your potential supplier to talk you through the solutions they’d advise.
One significant pro is that it can be much more energy efficient – especially a water-based system (more on which shortly). ‘It works at a lower temperature [than radiators] and will also contain heat for several hours in the floor once it reaches the optimum temperature,’ explains Gerald Stow. All types of underfloor heating also provide a much more even spread of heat than a radiator.
On the downside, initial installation is typically more expensive than a standard central heating system. It can also be less sensitive than radiators, which heat up swiftly once turned on and cool down rapidly (though electric underfloor heating systems usually heat up more quickly than water-based ones, but can be more costly to run).
However, clever use of the timer and thermostats, and even a weather sensor, can all help to manage this issue, so ask your potential supplier to talk you through the solutions they’d advise.
What kind of systems are available?
There are broadly two types of underfloor heating: electric, or ‘dry’, and a system run on water, often described as ‘wet’.
‘A dry underfloor heating system is where an electric heating cable is installed underneath the floor, and heats up when the electricity is switched on,’ explains Steven Rooney.
‘A wet underfloor system is where a pipe is installed beneath the floor and warm water is pumped around the pipe to heat up the floor.’ Wet systems work as part of the central heating system.
There are broadly two types of underfloor heating: electric, or ‘dry’, and a system run on water, often described as ‘wet’.
‘A dry underfloor heating system is where an electric heating cable is installed underneath the floor, and heats up when the electricity is switched on,’ explains Steven Rooney.
‘A wet underfloor system is where a pipe is installed beneath the floor and warm water is pumped around the pipe to heat up the floor.’ Wet systems work as part of the central heating system.
Why install dry underfloor heating?
Dry underfloor heating is powered by electricity and doesn’t require a boiler, which is ideal if you don’t have a gas supply. What’s more, once the system is laid, there are no further service or maintenance costs.
‘Electric underfloor heating doesn’t rely on the rest of the heating system, making it perfect for renovations,’ explains Steven. ‘So if an existing system is at capacity, electric underfloor heating can be installed without upgrading the boiler.
‘It also means that if the homeowner wants just a warm floor, they don’t have to turn on the rest of the heating, as you would with a system heated by a traditional boiler.’
Dry underfloor heating is powered by electricity and doesn’t require a boiler, which is ideal if you don’t have a gas supply. What’s more, once the system is laid, there are no further service or maintenance costs.
‘Electric underfloor heating doesn’t rely on the rest of the heating system, making it perfect for renovations,’ explains Steven. ‘So if an existing system is at capacity, electric underfloor heating can be installed without upgrading the boiler.
‘It also means that if the homeowner wants just a warm floor, they don’t have to turn on the rest of the heating, as you would with a system heated by a traditional boiler.’
How is dry underfloor heating installed?
With some care, dry underfloor heating can be laid by anyone with DIY experience. Often the cables come woven into a mesh mat, which makes installation simpler, and some very small systems even plug straight into the mains.
However, where this is not the case, the way the heating system is connected to the electricity supply is a specialist task, and an experienced electrician should carry this out.
Read reviews of electricians in your area.
With some care, dry underfloor heating can be laid by anyone with DIY experience. Often the cables come woven into a mesh mat, which makes installation simpler, and some very small systems even plug straight into the mains.
However, where this is not the case, the way the heating system is connected to the electricity supply is a specialist task, and an experienced electrician should carry this out.
Read reviews of electricians in your area.
Why choose wet underfloor heating?
Generally, wet underfloor heating is best suited to new builds or completely new extensions, because it’s embedded into the floor and may require floor heights to be adjusted. ‘Depending on the heat source, it will probably need some type of associated maintenance over the years, such as regular boiler services,’ says Steven.
‘You can tap into a local radiator circuit,’ says Gerald, ‘although I would only advise this for small areas or conservatories. For a more substantial area, I would make sure it’s an independent system. You won’t need an extra boiler for this, but you might need a bigger one. Always check this with your contractor before going ahead.’
Generally, wet underfloor heating is best suited to new builds or completely new extensions, because it’s embedded into the floor and may require floor heights to be adjusted. ‘Depending on the heat source, it will probably need some type of associated maintenance over the years, such as regular boiler services,’ says Steven.
‘You can tap into a local radiator circuit,’ says Gerald, ‘although I would only advise this for small areas or conservatories. For a more substantial area, I would make sure it’s an independent system. You won’t need an extra boiler for this, but you might need a bigger one. Always check this with your contractor before going ahead.’
Can it be installed under carpet?
Research by The Carpet Foundation and the Underfloor Heating Manufacturers Association has proved that most carpet types can be used over underfloor heating systems without weakening the performance of the system.
‘A carpet and underlay combination with a thermal resistance of less than 2.5 togs allows the underfloor heating system to operate most efficiently,’ says Joan Pask.
Research by The Carpet Foundation and the Underfloor Heating Manufacturers Association has proved that most carpet types can be used over underfloor heating systems without weakening the performance of the system.
‘A carpet and underlay combination with a thermal resistance of less than 2.5 togs allows the underfloor heating system to operate most efficiently,’ says Joan Pask.
Can it be installed under tiles?
When it comes to installing underfloor heating under stone, ceramic or porcelain tiles, the most important consideration is insulation. ‘Adding insulation is extra work, and it can feel like an unnecessary extra cost, but this is far from the truth,’ says Joan.
‘Using insulation boards in conjunction with underfloor heating is what’s going to reduce the running cost of your heating by as much as 50 per cent. It’s quick and easy to install insulation boards and it definitely provides more comfort, because you won’t have to wait long to feel the warmth. That’s because the insulation reflects the heat upwards into the floor tile instead of allowing it to be wasted on warming the concrete slabs below.’
Check out these small utility rooms that use space brilliantly.
When it comes to installing underfloor heating under stone, ceramic or porcelain tiles, the most important consideration is insulation. ‘Adding insulation is extra work, and it can feel like an unnecessary extra cost, but this is far from the truth,’ says Joan.
‘Using insulation boards in conjunction with underfloor heating is what’s going to reduce the running cost of your heating by as much as 50 per cent. It’s quick and easy to install insulation boards and it definitely provides more comfort, because you won’t have to wait long to feel the warmth. That’s because the insulation reflects the heat upwards into the floor tile instead of allowing it to be wasted on warming the concrete slabs below.’
Check out these small utility rooms that use space brilliantly.
What insulation do I need with tiles?
Insulation boards come in a wide range of thicknesses, from 6mm all the way up to 50mm. ‘Any level of insulation can save you money, but the thicker the better,’ advises Joan. ‘Building regulations require homes to be properly insulated, and should be referred to when determining the required thickness.’
Insulation boards come in a wide range of thicknesses, from 6mm all the way up to 50mm. ‘Any level of insulation can save you money, but the thicker the better,’ advises Joan. ‘Building regulations require homes to be properly insulated, and should be referred to when determining the required thickness.’
Can it be installed under wood floors?
Although underfloor heating is an excellent choice for almost all wooden floors, it’s essential it’s correctly specified to avoid damaging hotspots. Experts recommend that, before ordering wood flooring, you should check it is compatible with your underfloor heating system.
‘It’s important that wooden floors are not subjected to temperatures of more than 27 degrees,’ adds Gerald, ‘or the wood could start to crack or buckle. Always have floor sensors installed, which will protect against this happening.’
Although underfloor heating is an excellent choice for almost all wooden floors, it’s essential it’s correctly specified to avoid damaging hotspots. Experts recommend that, before ordering wood flooring, you should check it is compatible with your underfloor heating system.
‘It’s important that wooden floors are not subjected to temperatures of more than 27 degrees,’ adds Gerald, ‘or the wood could start to crack or buckle. Always have floor sensors installed, which will protect against this happening.’
How does it work best with wood?
‘Wood conducts less heat than stone or tiles, so the thinner it is, the higher the output of the system and the faster the heat-up time,’ explains Joan. ‘The maximum thickness for efficient heat output is about 18mm, but thicker boards can be used at a lower output.
‘The density of the wood flooring will also influence the heat transfer of the underfloor heating system,’ she adds. ‘Higher density floors transmit heat better.’ Investing in insulation will, again, reduce heat-up times and keep running costs to a minimum.
‘Wood conducts less heat than stone or tiles, so the thinner it is, the higher the output of the system and the faster the heat-up time,’ explains Joan. ‘The maximum thickness for efficient heat output is about 18mm, but thicker boards can be used at a lower output.
‘The density of the wood flooring will also influence the heat transfer of the underfloor heating system,’ she adds. ‘Higher density floors transmit heat better.’ Investing in insulation will, again, reduce heat-up times and keep running costs to a minimum.
Can it be installed under vinyl and laminate floors?
Vinyl floors can be sensitive to heat over time so do be careful here. The correct choice of underfloor heating is essential. Companies such as Warmup and others offer special heating systems that are suitable for heating under vinyls and laminates.
Shop flooring on Houzz.
Vinyl floors can be sensitive to heat over time so do be careful here. The correct choice of underfloor heating is essential. Companies such as Warmup and others offer special heating systems that are suitable for heating under vinyls and laminates.
Shop flooring on Houzz.
Always seek expert advice
Make sure you buy the correct system for your floor by seeking expert advice, advises Steven. ‘Always choose a system that has a full warranty – at least 10 years on the cables and five years for the thermostat. Make sure you purchase from a reputable retailer. It’s also a good idea to get references from the installer about previous projects that he or she has completed.’
Tell us…
Do you have underfloor heating, or are you considering installing it? Share your experiences in the Comments section.
Make sure you buy the correct system for your floor by seeking expert advice, advises Steven. ‘Always choose a system that has a full warranty – at least 10 years on the cables and five years for the thermostat. Make sure you purchase from a reputable retailer. It’s also a good idea to get references from the installer about previous projects that he or she has completed.’
Tell us…
Do you have underfloor heating, or are you considering installing it? Share your experiences in the Comments section.
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@WEndy what type of floor did you use in your kitchen with the wet UFH?
My parents' house didn't have central heating so it was a real shock to have underfloor hearing in halls in my first year at university, back in 1974. It made me drowsy while I was studying and I would wake up with dry sinuses (couldn't open the windows as it was on the ground floor). Not a good experience and couldn't wait to move out.
I'm pretty sure our floors are all concrete under the wooden floor so can I add wet UFH on top? Obviously I lose a bit of height but that's ok. I'd like to fit in the bedroom and en suite. Anyone have any thoughts on what is the best flooring to look good and feel good in both rooms? I'm in Madrid so cool tiles in the summer might actually be quite nice! The bedroom isn't much bigger than the bed so is it worth it? Any thoughts gratefully received