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 Pros and Cons of Installing Underfloor Heating?

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

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:

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.

For a wet system, the 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.

For a dry system, heating mats or 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.

It is possible to install a dry underfloor heating system yourself, providing you have some basic DIY experience.

However, any electric connections will need to be completed by a qualified electrician.

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.

Building Regulations or Planning Permission Approval for Underfloor Heating Installation

You usually won't need planning permission to install underfloor heating in your home.

However, the system needs to comply with building regulations.

These regulations also apply:

• If you're installing underfloor heating as part of a house extension, renovation, or alongside adding a conservatory, you'll need planning permission and building control approval.
• All underfloor heating systems must be compliant with Part L (energy efficiency) of building regulations.
• Any electrical connections must comply with Part P (electrical safety) of building regulations.
• If connecting to a gas boiler, 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 ask these questions:

Are you qualified to install underfloor heating?

Electric systems need to be connected by a qualified electrician, and any systems using gas need to be fitted by a Gas Safe registered engineer.

Are you insured to install underfloor heating?

Ensure the contractor has public liability insurance which will protect you and them should anything go wrong during the installation.

Will there be much disturbance during the underfloor heating installation?

While most underfloor heating installation jobs are basically disturbance-free, you should ask the tradesperson how disruptive the job will be.

Is my boiler compatible with an underfloor heating system?

Most boilers work with underfloor heating. However, old or small boilers may need upgrading.

Will my floor type work better with a dry or wet underfloor heating system?

By asking this, your installer can advise which underfloor heating system is best for your flooring.

FAQs