How to Choose Underfloor Heating

Looking for an efficient way to heat up your home? Well, if you know the horror of stepping onto a cold bathroom floor in the winter in bare feet, then you’ve probably at least considered underfloor heating (UFH) for your home. But how do you know if it’s the right choice for you, and if it is, which type of installation should you choose? If these are questions you find yourself asking then read on as this handy guide will tell you all you need to know…

The Pros and Cons of Underfloor Heating

First, let’s consider some of the benefits of underfloor heating. Not having to use radiators means freeing up valuable wall space for furniture placement and the heat radiates from all over the floor. As heat rises, the entire room gets warm rather than just the area in front of a standing heating system. And of course, there’s no worry of cold feet on bare floors!

UFH also creates a pleasant heat with no cold spots, distributes that heat evenly, and gently warms a room without waste. It’s 40% more efficient than radiators so better for the environment too and will save you on your heating bills in the long run. Once installed, there’s very little maintenance and virtually no chance of flooding. However, if you do run into a problem with it, you will need to rip up flooring to fix it which can be costly and inconvenient.

It’s also worth remembering that UFH can be costly to install, especially if you want to install it under existing flooring. If you are creating new floors from scratch in a new build, an extension, or if you are going to be replacing the flooring in a space, then underfloor heating may be a great choice. Having to rip up existing flooring, however, may be more work than you are willing to do so you need to weigh this up when deciding whether UFH is for you.

How Many Different Types of Underfloor Heating Are There?

There are basically two types of underfloor heating to consider – wet or electric:

Hot Water or Wet Systems

These systems work in conjunction with your central heating system and warm water is pushed through a system of small pipes on a subfloor to heat up a room. The pipes are continuous which means there is less chance of leakage through the joins and your surface flooring is laid above them. Because the central heating system doesn’t have to heat the water to as high a temperature as a radiator would, you’ll also enjoy lower heating costs.

Wet systems can run off any central heating system provided it’s big enough although generally, combination boilers are the most efficient. Each room can be controlled individually via individual thermostats (usually wall-mounted) or via a thermostat hub located in a single location. More subfloor space is usually required in order to install wet systems as they sit higher than their electric counterparts, meaning your flooring will sit higher. So, if you were to install this in the kitchen for example, you may have to take into consideration that the floor level may not be even to those in adjoining rooms.

Electric Underfloor Heating

Electric UFH comes in two formats; Mat Kits and Loose Cable Kits. The former comprises a system of pre-spaced heating elements mounted on an open weave mat (that comes on a continuous roll) and operates in much the same way as an electric blanket does. Loose Cable systems on the other hand are simply a continuous cable that can be laid beneath floor finishes (not restricted by the layout/dimensions of a mat) that generates heat when switched on.

Both these types of UFH sit flatter than wet systems owing to the lack of somewhat bulky piping, meaning that electric kits are much more versatile as your sub-floor doesn’t have to be adjusted to accommodate any pipes. Electric UFH systems are simply rolled out, connected to your electricity supply and the new flooring installed on top of it. Ahead of installing an electric UFH system it’s extremely important to ensure that you have correctly measured the space in which the installation will be housed and purchase the right amount of matting or cable – for more info on how to do this check out our How To Measure for Underfloor Heating Guide.

Where to Use Underfloor Heating

Because of the requirement for sufficient sub-floor capacity, wet systems are normally best used on ground floors or in new build projects, but really, you can use underfloor heating in almost any setting providing that the sub-floor can accommodate the system. UFH can be used with virtually any kind of flooring too – even carpets, provided the carpet and underlay have a heat-resistance of less than 2.5 tog – but there are a few things to consider when using UFH with tiles and other flooring types.

Using Underfloor Heating with Tiles

If you wish to use UFH beneath tiles, then the time taken to heat up your room will depend upon the thickness of your tiles. Thicker tiles will naturally take longer to heat up but once at temperature, there is virtually no difference to the heat output achieved when installed beneath thinner tiles. Both wet and electrical systems can be used in conjunction with tiles but whether each type can be installed in a specific situation will all depend on the subfloor and whether the substrate that will be tiled onto is suitable. Electric UFH systems – both Loose Cable and Mat Kits can be used with ceramic and porcelain tiles, as well as natural stone tiles including limestone, marble, slate, terracotta, and quarry tiles. It’s also important to always use a flexible adhesive such as Mapei Keraquick and ensure you have the right sub-floor for the installation – more on this later though…

Installing Underfloor Heating

For any system to work efficiently, you need to ensure your home is well insulated and that sub-floors in areas that will house a UFH installation can accommodate them. Installation of an electric system is a relatively straightforward DIY task and once installed, the systems are virtually maintenance free. Please be aware however that you will need to use a Part P qualified electrician to connect the system to your electricity supply and install the thermostat and temperature probe.

Wet systems are a lot more complicated and should be installed by a qualified tradesmen. As such, installation of this type of system will cost considerably more but engineers will take into consideration things like your ceiling height, the temperature at which the water will need to be heated, and your boiler capacity, as well as the type of flooring you wish to install on top of the system.

Subfloor Considerations

As mentioned, when installing electric UFH systems for use with tiles you will need to ensure that the adhesive you choose is flexible and that the sub-floor that is having the UFH installed onto it and tiles laid over the top is suitable. When installing UFH onto non tongue & groove floorboards, the boards will need to be overlaid with a minimum 15mm WBP or marine ply.

Chipboard and/or existing tiles must be either primed with Mapei Eco Prim Grip and/or covered with insulation boards such as Norcros 6mm Pro Insulation Board. Please note that MDF is not suitable for tiling or electric underfloor heating.

For best results insulation boards are highly recommended for use when installing UFH onto concrete floors. Using insulation boards in this situation will decrease warm up times by 50%, ultimately resulting in lower electricity consumption by your UFH system. It’s also advisable to prepare any floor with a screed such as Mapei Ultraplan ahead of installing UFH – this will help prevent hotspots and disperse the heat evenly and also protect the kits during tile installation.

Hopefully this article has answered some of the more pressing questions about underfloor heating and the installation of which. If not then please check out our other articles about UFH and do feel free to contact our friendly customer services team on 01782 223822 or speak to us via LiveChat for some free, impartial advice!

You might also enjoy these posts on the Tile Mountain blog…

How To Measure for Underfloor Heating

How to Lay and Install Underfloor Heating Mats

Best Tiles For Underfloor Heating

Here at Tile Mountain, we not only have a huge range of tiles to suit every purpose, we also have a wealth of tiling knowledge gained from over 30 years in the tile industry, (which we’ll do or best to share with you across these very pages).

Whether you’re looking for the perfect tiles for your next home improvement project, are searching for some style inspiration, or simply need a bit of help and advice, you’re in the right place.