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Things to Consider

Different underfloor heating systems vary in performance, so it is important to choose the right system for your project. To decide which pipe fixing system is best, you need to consider how the floor has been constructed as well as the desired final finish.

A system for every floor construction

Screed floors and underfloor heating
Using thermal conductivity these systems transfer heat from pipes encased in screed to the finished floor level and are typically used for ground floor applications in new builds. Screed systems are constructed over slab or an oversite base with edge insulation fitted around the perimeter to allow for expansion and contraction as well as the prevention of heat conduction from the floor to the wall.

Timber floors and underfloor heating
Laid directly on top of existing solid floors or under the floor between timber joists or over the floor between battens. There is a range of options for retrofits using low profile, high density, grooved foil-faced panels.

Existing floors and underfloor heating
Timber floor systems use heat diffusion plates to dissipate heat evenly. The system consists of insulation fixed between joists and aluminium spreader plates securely fitted between or above the timber joists/battens. The underfloor heating pipe work is then fixed into the plates.

A system for most floor finishes

John Guest Underfloor Heating is suitable for almost all types of floor finish. However, some floor finishes offer better thermal conductivity than others and can therefore impact system performance.

Ceramic & Stone Most
Ceramic and stone floor finishes have a low thermal resistance. The hard surface quickly and effectively transfers heat making it an ideal partner for underfloor heating.

Timber Wood
Due to good heat transfer properties timber floors work well with underfloor heating. Engineered timber is particularly suitable for underfloor heating, maximum floor temperature should not exceed 27°C and due to the nature of the material advice should be sought from your supplier.

Vinyl & Linoleum
Vinyl and linoleum flooring offers low resistance to heat due to its thin layer. Most types of vinyl and linoleum are suitable for use with underfloor heating but the temperature should not exceed 26°C. Carpet Carpets and underlay provide the highest heat resistance. You must make sure that the underlay is suitable for use with underfloor heating and that the combined carpet and underlay tog value is less than 2.5. The higher the combined tog value the greater the reduction in heat output.

For most applications underfloor heating systems has a surface temperature of approximately 25°C. However, some situations – where building heat loss is high – will require a surface temperature of 29°C. Always ensure the underfloor heating system is designed to meet the floor finish manufacturer’s instructions on maximum temperature.

John Guest has a wide range of underfloor heating systems designed to work with almost any floor construction.