Underfloor Heating System FAQs

What is underfloor heating?

Underfloor heating systems utilise the entire floor area within a room as a heat emitter, delivering ultimate comfort effectively and efficiently.

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Can only new builds have underfloor heating?

Underfloor heating is not restricted to new build properties, it can be also be installed as a retrofit project into many older properties.

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Can underfloor heating only be used on ground floors?

No. UFH can be installed both upstairs and downstairs in a property. Please read more about underfloor heating specifications here.

How long does installation of an underfloor heating system take?

Grant's underfloor heating systems include, Uflex and Uflex MINI. With a drying time of thirty days, the Uflex underfloor system is best suited to the new build and renovation market, this is so the underfloor system can be fitted as part of the floor construction process. Uflex MINI, however, has a drying time of 3 days. It is suitable for both new builds, as well as retrofits and renovations, when an underfloor heating system is to be fitted in a property with a floor construction already in place. At just 15mm in height, this underfloor system can be installed incredibly quickly and with minimal disruption to a property’s existing floor and door arrangements.

Can underfloor heating be added to my existing heating system?

Underfloor heating is suitable for gas, oil, and LPG boilers as well as heat pumps and biomass boilers. For more information, speak to our Renewables Team.

Do I need to dig up the floors for underfloor heating?

No. The Uflex MINI system is specifically designed to suit retrofits and renovations, when an underfloor heating system is to be fitted in a property with a floor construction already in place. At just 15mm in height, this underfloor system can be installed with minimal disruption to existing floor and door arrangements.

Does underfloor heating work the same way as a radiator?

Radiators use air circulation to emit heat into a room whereas underfloor heating warms a room when the hot air rises from the floor. Radiators do therefore work differently compared to an underfloor heating system. 

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Which type of underfloor heating is best for my flooring?

Not all types of floor finishes are compatible with underfloor heating systems so it is important to research suitable floor coverings which will allow the heat from the underfloor heating system to be transferred into a room.

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Is underfloor heating cheaper to run than traditional heat emitters?

Yes, data suggests that underfloor heating can be 25% cheaper to run than radiators when used in conjunction with a condensing boiler and up to 40% cheaper to run when used with a heat pump (EuRay 2005.)

What is overboarding and do I need it for underfloor heating?

Overboarding involves the fitting of an overlay or base layer in between the screed and the floor finish. Some types of underfloor systems, such as electric UFH, require a form of overboarding to be fitted as standard. However, Grant’s Uflex underfloor system does not need overboarding which allows installers to lay the final floor covering directly on top of the dry screed.

What is an underfloor heating manifold?

The manifold is the system hub for the underfloor. The pipes are connected to it at the installation stage and it then controls the distribution of the water from the heating system's source (boiler/heat pump) throughout the underfloor system. It is at the manifold that the control of the flow to each individual zone or room is achieved.

Where should a manifold for underfloor heating be situated?

The manifold should be located in a central point where the pipework is most evenly distributed.

Can I fit underfloor heating under a kitchen unit?
Yes, providing there are no fixings that may damage the pipe, we advise to lay the underfloor across the total floor area as the future layout could be different. We do not recommend the underfloor to be fitted below sanitary items as these are often fixed to the floor and could damage the pipes.
What are the benefits of underfloor heating?

Underfloor heating is an effective and efficient choice of heat emitter. It transforms the entire floor surface into an area where warmth can be emitted into a room, evenly heating the space up and delivering optimal comfort. Visit our Knowledge Hub to read more about the many advantages of installing an underfloor heating system

What are the advantages of installing wet underfloor heating?

A wet underfloor heating system offers homeowners many advantages including even heat distribution, space saving, excellent energy efficiency and of course comfort.

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Is my home suitable for an underfloor heating system?

Yes. With so many underfloor heating systems available, there is a system that will suit your home whether that be a traditional screeded UFH system, a low profile UFH system, a dry, non-screed UFH system, or installation options (such as heat emission plates) for first and upper floor areas.

Which floor coverings work best with underfloor heating?

Floor coverings which have low thermal resistance are best for underfloor heating systems. Materials such as tiles, stone and vinyl, for example, allow for a good transfer of heat and are ideally suited for an underfloor heating system. Thick carpets on the other hand will restrict the movement of heat from the UFH system to the room and carpets (including overlay) with a tog of 2.5 are not suitable.

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I have a boiler and radiators – can I have underfloor heating too?

Yes. Underfloor heating systems are suitable for installation with gas or oil boilers. They can also be installed alongside radiators - in most situations underfloor heating system is installed downstairs and radiators are installed upstairs.

Will my pets be safe sleeping on underfloor heating?

Yes. Underfloor heating systems are designed to not exceed certain temperatures which means that their temperature to the touch remains safe for pets as well as children or anyone walking bare foot.

Why should I choose a designed UFH system?

For an underfloor heating system to work effectively and to ensure that it is installed to aid the overall efficiency of the heating system, it is crucial that the system is professionally designed. The positioning of the pipework, including the spacing between the pipes, the pipework configuration and the amount of pipe laid, must be accurately calculated and drawn up. Poor system design can lead problems such as underheating or overheating of a room.

Can an underfloor heating system be installed without traditional screed?

Yes. Certain types of underfloor heating systems can be installed as “dry systems” which means they do not require a traditional cement screed to be poured over them. The Grant Uflex and Uflex MINI Overlay Board systems are both dry UFH systems which use polystyrene boards with pre-formed grooves for the pipework to be positioned and a suitable floor covering laid on top.

Which underfloor heating systems best suit retrofit installations?

Low profile underfloor heating systems lend themselves well to retrofit installations because systems, such as the Grant Uflex MINI UFH, use self-adhesive panels which can be laid on top of an existing floor, providing it is sound and level, and using a self-levelling compound to create the finished floor surface. Furthermore, low profile UFH systems may not affect existing door and skirting board arrangements. Dry, non-screeded UFH systems are also ideally suited for existing properties as there is no need to dig up existing floors.

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How long does it take to install an underfloor heating overlay board system?

Every installation is different and the installation time will be dependent on the size of the room(s), the number of installers and their level of experience. To give an example, the installation of a Uflex Overlay Board underfloor heating system on a floor area around 136m² in size could take an experienced team of four installers approximately two days to complete. To learn more about the steps involved in installing an overlay board UFH system, please watch our video here.

What are the advantages of an underfloor heating overlay board system?

With an overlay board underfloor heating system, there is no need to pour a screed which makes the installation quicker than a traditional screeded UFH system. Grant’s overlay boards are slim, being between 16mm-20mm in thickness, so once installed they make minimal increase to the height of an existing floor. Read more about the Grant overlay board UFH system here.

What are the disadvantages of an underfloor heating overlay board system?

It is imperative that your installer plans the layout and orientation of the overlay boards in advance of installation to ensure that the pipework arrangement is in line with the system design. Overlay boards are suitable for use with most types of floor covering, including tiles and wood laminate, but in some instances, it may be necessary to lay ply over the overlay boards and pipework before certain types of floor covering are laid.

How can underfloor heating transform a conservatory?

Installing underfloor heating in a conservatory can help homeowners utilise this space all year round, providing heat to a type of room which can often be left unoccupied during the colder, winter months.

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Can you install underfloor heating on a suspended floor?

Yes, certain types of underfloor heating can be installed on a suspended timber floor with wooden joists, whether this be on the ground floor or on upper levels.

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Package Solutions

A heating system’s overall efficiency can be significantly improved by combining multiple technologies. From heat pumps to cylinders and effective heat emitters, you can get all of these products from Grant.

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