Buyer's guide: Underfloor heating
Pros & cons
Having your heat source installed at the lowest point in the room makes perfect sense from an efficiency point of view, as heat rises. Underfloor heating systems can be 40 per cent more efficient than radiator based systems, so they are kinder to the environment and, over time, your bank balance (although installation costs are high).
Used in conjunction with radiators or on its own, it can free up wall space for shelves or cupboards, or for a minimalist look, offer nice clean lines. There are no hot and cold spots as heat is distributed evenly across the surface. An underfloor heating system should not require any maintenance and flooding is virtually unheard of. However, if you were to suffer a burst pipe, you would have to tear up the flooring to fix it, which would be a major headache and expense.
Underfloor heating can be used with any type of floor construction, although it is much easier where you are laying flooring from scratch so you do not have to lift up existing flooring. For this reason, new builds or extensions are ideal. Underfloor heating systems are compatible with many different floor surfaces including carpet, ceramic tiles and stone. It is particularly welcome under the latter surfaces which can get very cold in winter. Certain types of timber, vinyl and laminates can also be used with underfloor heating systems but it is essential to seek professional advice to ensure you get the right type. It is also a good idea to get advice on the optimal thickness of flooring to use in order to achieve maximum energy efficiency, as this will vary according to the material.
The two main types of underfloor heating are electric and wet systems. Where you are having to work with existing flooring, the best system to install is an electric one as it is flatter than water-based systems so should not require the floor height to be raised in order for it to fit underneath. Electric under-floor heating uses cables attached to or embedded in mesh mats, which are connected to the power supply like a giant electric blanket. They are normally easier to install, but between 30 and 40 per cent more expensive to run than water-based systems. Ribbon systems and carbon film are particularly flat, so ideal for minimal disruption to floor structures.
Water-based underfloor heating uses a system of plastic pipes beneath the floor surface which are filled with warm water from the central heating. The pipes are normally continuous to eliminate the chance of leaks through joints. Water based systems can run off any boiler providing it is large enough, although gas condensing boilers are the most efficient. Some wet systems can also be used to create a cooling effect in summer. Each room has its own valve but these can be stored in an overall control hub in a cupboard.
Simple electric mat systems could be installed yourself, but not waterbased systems, and you should always get advice to ensure your flooring material is compatible or you could end up with warping. You can buy do-it-yourself kits for around £400. Having a system installed for you will be much more expensive at around £5,000 for an average sized property. The floor beneath the heating system needs to be well insulated to prevent heat loss.