Underfloor Heating Installation Guide

Have you ever considered installing underfloor heating?

It just may be the most cost-effective way to heat your entire house.

To help you decide whether underfloor heating is right for you, this guide will cover everything you need to know, including underfloor heating installation costs, pros and cons, and how to find an underfloor heating specialist.

Let's get started.

What Is Underfloor Heating?

Underfloor heating involves the installation of pipes beneath your floor to heat your home from the ground up.

Because underfloor heating systems run at lower operating temperatures compared to a traditional radiator system, there's less demand on your boiler, giving you better energy efficiency.

Working well with renewable technology, underfloor heating is a smart choice for homeowners looking to reduce their reliance on fossil fuels.

Types of Underfloor Heating

Underfloor heating comes in two main types: wet (water-based) and dry (electric).

Dry Underfloor Heating

With dry underfloor heating, electricity is used to heat your floors with heating cables or mats fitted underneath the floor's surface.

There are three choices of dry systems:

• Loose wire – Best suited for stone or tile floors, and a great choice for awkward-shaped rooms
• Matting – Works well with stone or tiled floors and rooms that are large and regularly-shaped.
• Foil mat – Designed specifically to work with laminate flooring.

The main takeaway: Dry electric underfloor heating is cheaper and easier to install in existing homes, but the running costs can be three times higher than wet underfloor heating.

Wet Underfloor Heating

Wet underfloor heating systems use a network of pipes laid beneath your floor, connected directly to your central heating system.

Most modern boilers will have enough capacity to power a wet underfloor heating system.

The main takeaway: Wet underfloor heating is best installed in brand new properties instead of being retrofitted because of the complexity of installation. Running costs are lower than those of a dry system, making it more cost-effective for larger properties.

What are the Best Types of Flooring for Underfloor Heating?

Choosing the right flooring is a key decision towards to getting the most from your new underfloor heating installation. Not only is it about home comforts, but also about which material has the best tog rating, while helping to distribute and retain heat the most effectively, making your system as energy efficient as possible.

Below we compare some of the most common types of flooring and their pros and cons in relation to having underfloor heating installed:

Tiled Floors (Porcelain, Stone and Ceramic Tiles)

While stone and ceramic tiles are still practical, porcelain tiles are often the most popular choice. Tiling a floor generally has a tog rating of 0.1 to 0.2, which makes them a great match for underfloor heating.

Pros

• ✔ Great for transferring heat
• ✔ Durable and water-resistant

Cons

• ✖ Can be cold when underfloor heating isn't on
• ✖ May develop cracks if the subfloor isn't stable

Luxury Vinyl Tile (LVT)

LVT has a tog rating of 0.3 to 0.5. While this isn't as low as tile floors, it's still within the optimal range for compatibility.

Pros

• ✔ Lots of design choices and colours for different home decor
• ✔ Comfortable to walk on

Cons

• ✖ Surface may warp if the temperature is too high, or the LVT isn't underfloor heating rated
• ✖ Must have a specialist underfloor heating adhesive

Engineered Wood

Engineered wood flooring comes with a tog of 0.5 to 1, which means some flooring designs can be too thick to achieve optimum heat transfer.

Pros

• ✔ Gives a homely, natural aesthetic
• ✔ More forgiving than hardwood flooring

Cons

• ✖ If the flooring is too thick, the heat won't transfer as well
• ✖ Can be sensitive to excessively high temperatures

Laminate

Laminate flooring rates between 0.5 to 0.7. You'll need to choose an underfloor heating compatible variant for best results.

Pros

• ✔ Affordable and easy to install yourself
• ✔ Easy to clean and maintain

Cons

• ✖ Lifespan is typically shorter than other flooring types
• ✖ If the laminate isn't rated for underfloor heating, it can warp over time

Carpet

Carpet has a high tog rating of around 2.5, making it less suitable for underfloor heating than other flooring options.

Pros

• ✔ Warm, cosy feel
• ✔ Comfortable underfoot

Cons

• ✖ Thick carpets aren't suitable for underfloor heating as they trap the heat
• ✖ Not suitable for all rooms

What Are the Pros and Cons of Installing Underfloor Heating?

Whether you're planning on looking at dry electric heating systems or wet, water underfloor heating systems there are always pros and cons included depending on your personal requirements.

Let's look at the advantages of installing underfloor heating first:

Pros

• Energy Efficient Heating – The increased energy efficiency of underfloor heating makes the system cheaper to run, as each room can be individually controlled. Underfloor heating runs at a lower surface temperature than traditional radiators. The system warms rooms using radiant heat, which consumes less energy and can help to reduce annual heating bills by 15% on average.
• More Space – With an underfloor heating system, radiators won't take up space on the walls. On average, underfloor heating frees up 10% of wall space that radiators would otherwise take up. This gives you more space to fit furniture or put paintings on the wall without working around bulky radiators.
• Works with All Types of Floor Coverings – Underfloor heating works well with laminate, wood, tile, stone and carpet. The systems can also be adapted to work with other floor types – such as concrete – which is found in many modern homes.
• Safety and Comfort – Underfloor heating systems are safely tucked away under the floor, with no exposed edges or hot surfaces. They also feel comfortable underfoot, which is perfect for cold mornings in the bathroom, as the tiles will feel much warmer.
• Ease of Installation – Underfloor heating systems are suitable for both new-build projects and retrofitting. Electric systems can be installed in a room in as little as 1 to 2 days, depending on the project. Water systems will generally take longer to install due to the complex laying of pipes involved, and the need for skilled plumbers.

Now, let's consider the disadvantages of installing underfloor heating in your home:

Cons

• Takes a While To Warm Up – An underfloor heating system can take a while to warm up. The systems aren't as quick as radiators to heat up, so it's best to use a timer or install a smart thermostat to make sure your rooms are warm enough when you need them to be.
• Not Suited to Small Systems – If your system is too small, you may have a warm floor, but the rest of the room will still be cold. In these situations, you may need to supplement the system by installing radiators. A small system will need to be upgraded to a larger installation, which can significantly increase your costs.
• Installation Cost – Underfloor heating can be fairly expensive to install. Water-based systems have more complex installation requirements and usually take longer to install. Although a wet underfloor heating system will initially cost more, the lower running costs in the longer term can offset the initial price.

How Much Does It Cost to Install Underfloor Heating?

The cost of installing underfloor heating varies greatly depending on the type of system.

Electric underfloor heating costs around £40 and £90 per m².

This equates to:

• Small downstairs toilet (2m²) - £160 to £180
• Ensuite bathroom (4m²) - £240 to £300
• Medium-sized kitchen (12m²) - £600 to £900

Wet underfloor heating costs around £100 to £190 per m².

This gives you costs of:

• Small downstairs toilet (2m²) - £340 to £380
• Ensuite bathroom (4m²) - £600 to £720
• Medium-sized kitchen (12m²) - £1,200 to £1,500

The size of the room and the type of flooring will also factor into the price, as will ease of access and property location.

You may also want to consider additional costs such as installing a new boiler, which you may have to consider if your current system is small.

If installing underfloor heating before flooring, you will also have to factor in the cost of the new floor, which again will vary depending on the type of floor you choose.

How Is Underfloor Heating Installed?

The process of installing underfloor heating will differ for each type, although both dry and wet systems require the floor to be removed, followed by laying insulation and installing a damp proof membrane.

• Wet System - Water underfloor heating systems have their heating pipes will be installed in a looping pattern and fixed in place with pipe staples. Once this is complete, the system will be connected, filled, and tested for safety and functionality.
• Dry System - Electric heating mats or electric cables will be laid out on top of the insulation and secured with double-sided tape. A floor sensor will then be connected to a thermostat, which should be taped down at floor level. At this stage, you will need to call in a qualified electrician to connect the system and certify the job.

Once the underfloor heating has been fully installed, the complete system is tested to check the heat distribution and to ensure everything is operating safely and efficiently before the final floor covering can be laid on top.

How Long Does It Take to Install Underfloor Heating?

Installing a wet system into a new build house can take between 2 to 4 days, but larger or more complicated installations will take longer.

If the heating is installed in an existing property, preparation will be needed before the pipes can be laid, which can take 1 to 2 days longer.

The process is complicated, but can be completed quickly on a new build by experienced fitters.

Installing a wet system into an existing property can be problematic. It may require digging up the floor or raising the floor level to accommodate pipework.

Can I Install Underfloor Heating Myself?

Wet underfloor heating systems are not DIY friendly and electric underfloor heating needs to be installed by a Part P qualified electrician.

Installations that need to be connected to your main boiler are simply not worth doing on your own, as they can prove dangerous if done incorrectly and any mistakes can prove costly. As such, always consult a local heating engineer or underfloor heating company to advise you of the work required before taking on this job.

A survey carried out by a professional will help you select the best underfloor heating system and ensure your boiler can support the additional heating system. However, DIY electric underfloor systems using heat mats are much simpler and cheaper to install. However, you will still need an electrician to connect the power up to your heating system.

For those who are confident in their DIY skills there some basic DIY wet underfloor heating kits available. These are typically designed for areas such as a single bedroom or small bathroom, and would make the underfloor heating expensive and not very practical if you tried to use them throughout the whole property.

These kits include a heat pump, valves, thermostats and pipework to heat around 20 square metres. If you did most of the work DIY and just hired a plumber or heating engineer for important steps, such as connecting the system and your boiler interface, you could potentially have a small wet underfloor heating system for around £1,000 (albeit depending on the size of room).

Building Regulations or Planning Permission Approval for Underfloor Heating Installation

For the majority of modern homes, you usually won't need planning permission to install underfloor heating, unless it is part of any major structural work such as knocking down a load-bearing wall or building an extension. However, you may need to request permission if you are replacing traditional heating methods in a property registered as a listed building or located within a conservation area.

If unsure, check with your local planning department before arranging contractors to carry out any work.

These regulations also apply:

• If you're installing underfloor heating as part of a house extension, conservatory or house renovation, building control approval is required.
• All underfloor heating systems must also be fully compliant with Part L (energy efficiency) of building regulations.
• Electric underfloor heating or electrical connections must comply with Part P (electrical safety) of building regulations.
• If connecting to a gas boiler, by UK law you must have a Gas Safe registered engineer to fit it legally.

If you're in any doubt, ask your contractor or contact your local building control department for guidance.

Questions to Ask When Hiring an Underfloor Heating Specialist

If you're considering upgrading your heating system, make sure you consider the following points:

• Are they qualified to install underfloor heating? Electric underfloor heating needs to be connected by a fully qualified electrician, and any systems using gas need to be fitted by a Gas Safe registered engineer.
• Are they insured to install underfloor heating? Most professional contractors are at least covered by public liability insurance, which will protect both them and yourself should anything go wrong during the installation.
• Is your boiler compatible with an underfloor heating system? Most boilers should work fine with underfloor heating. However, it's worth asking ahead of arranging any work in case you need to have your boiler upgraded.
• Will my flooring work better with dry or water underfloor heating systems? By asking this, your installer can advise whether an electric underfloor heating system is appropriate or if water underfloor heating is more suitable.
• Is there likely to be much disruption during the installation? It's good to understand how much the installation process will interfere with everyday life, especially if you're likely to have your power switched off temporarily.
• Have you received more than one quote? Multiple quotes are always recommended, as finding more than one local heating engineer via MyJobQuote can help you gauge the best price.
• Do they have evidence of positive feedback? Search their MyJobQuote profile for reviews and customer feedback, check comments on social media, and look for any further online testimonials.

FAQs