Thinking of installing underfloor heating?
We get a lot of questions concerning under floor heating and as we only sell wet systems we will concentrate on those.
So what's the point of using underfloor heating?
Well it's efficient, and underfloor heating is even more efficient when fitted over insulated floors, as a result it is also more cost effective. The extra insulation ensures downward heat loss is reduced and the heat flows up into the room.
Wet systems dissipate heat better when the pipes are embedded in a screed and these types of systems are therefore more likely to be used in new-builds and extensions or during major renovation work.
As a sidenote: Building Regulations generally ensure that new-build homes or extensions have sufficient floor insulation.
You should ensure you have a suitable space to fit the underfloor heating controls. They are usually situated together, they do not need a lot of space, under the stairs or even a spare cupboard can suffice.
Each room or zone will require its own valve, there will usually be a manifold for multi-room systems, a pump and a heating thermostat is required regardless of the number of rooms and each rooms size.
All of the plastic pipe installed is continuous, this eliminates leaks as there are no joints. When installed correctly the system is maintenance-free. Any boiler can be used with UFCH, as long as it has a sufficient capacity.
DIY - Can I fit underfloor myself?
Many of our customers do this. Retrofit projects can be done easily, and prove very efficient when extra floor insulation is fitted.
If you can access your existing floorboards add extra, or install new more efficient insulation. Insulation installation is generally easy, especially between floor joists.
If you are considering adding screed floor insulation it will increase the floor height in the room, that can result in some extra work adjusting skirting boards and doors.
When laying this type of screed floor we recommend approaching a specialist reputable company for advice as every home is different.
How do radiators work with underfloor heating?
Wet systems such as Polypipe use plastic barrier pipes underneath the floor to circulate the warm water. These are connected using manifolds to your central heating source.
It’s important to identify the pipe type and size of your existing system, you can then select the correct products to match.
Household heating costs should be reduced as wet underfloor heating (UFCH or UFH) systems produce temperatures between 40°C and 65°C.
Average floor temperature will therefore be between 23°C and 32°C - lower than the average domestic radiator.
How quickly does underfloor heating work?
The flooring material you use will affect the heat up time. Materials with low thermal mass and high conductivity are best.
They transfer heat quickly from the underfloor heating pipe to the floor surface. However, the reverse is also true as these materials cool down quicker than those with a high thermal mass.
Heat transfer can be improved if you fit insulation boards beneath the floor finish.
Underfloor heating floor coverings, what can I use?
Underfloor heating can be used with any material - systems are available to use with nearly any floor finish. However the key to this is the material’s thermal conductivity, essentially how quick and efficient heat transfers to the floor surface. Any floor covering with good conductivity gives more heat output and as a result is more efficient to run.
What floor materials work with underfloor heating?
Stone and Tile
Highly conductive, this is the best type of flooring to use with underfloor heating.
High thermal conductivity means excellent thermal properties - the heat in the pipes under the floor is transferred quickly into the room.
Tile and stone also retain heat well making the system very efficient. Excellent for conservatories as they can give a high heat output up to 200W/m².
When installing on any concrete subfloor, always install insulation. For a heat responsive system check the tile thickness, around 20mm is best.
Also check the tiles thermal limitations, the maximum floor temperature should be kept around 27°C to avoid damage.
- - Flagstones and floor slate - Naturally highly conductive and great with underfloor heating.
- - Marble - Good thermal conductivity, but slower heat up.
- - Ceramic & stone tiles - Excellent heat transfer properties & thin profile.
- - Polished & finished screed - Highly conductive allowing fast heat up time.
As above, all wood has different thermal properties. For Underfloor heating thin, dense flooring is best, they conduct heat more efficiently.
Check with the supplier to ensure the floor type you choose is suitable for underfloor heating. Wood that has been kiln-dried tends to work well because its moisture content is low. To ensure the floor keeps its appearance ask for a wood that is capable of dealing with moisture and temperature change.
Attention must be paid to the thickness of the floor boards so that they do not act as an insulator blocking the heat.
It’s important to check the moisture content of your wood flooring both before and during installation, you can then determine the correct heating cycle.
An excellent choice is engineered timber, laid directly over the underfloor heating. Boards should be around 20mm thick to avoid extra cost for structural supports.
If you choose soft thicker timber, be aware that they can insulate the pipes from the floor surface limiting the heat. The floor temperature restriction here is also a maximum of 27°C.
Solid hardwood can be prone to warp due to humidity and temperature changes, so check you’re your supplier or manufacturer to ensure it is compatible with your underfloor heating type.
Available in either solid wood or engineered timber, parquet floors are well suited for underfloor heating.
We also get asked if bamboo can be used. Bamboo has similar construction characteristics to engineered wood. It is a good conductor of heat, it is well suited for use with underfloor heating.
Most carpet is suitable for use with underfloor heating systems without impairing the performance of the system.
A carpet with underlay should have a combined thermal resistance of less than 2.5 tog, this allows system to operate efficiently.
Felt is not normally recommended as it has a greater thermal resistance than crumbed rubber. Thinner rubber products perform best.
Check adhesives to ensure they are suitable for use around 29°C. Your heating should be switched off for 48 hours prior to and after installation.
After installation the heating system should be brought up to its working temperature slowly, usually over a period of a week.
Vinyl & Rubber
Vinyl flooring can be used with underfloor heating it heats up and cools quickly but they are unsuitable for conservatories due to the high heat loss and an upper heat limit of 27°C.
Rubber can be used with underfloor heating it also is highly conductive it heat up quickly and has a good heat output.
As with nearly all other materials we recommend your supplier or the manufacturer to confirm suitability of use.
Generally it’s easy to fit and a cost effective solution although products such as Amtico and Karndean may need specialist fitting.
Many laminates are suitable for use with underfloor heating, but check with the flooring supplier or manufacturer before installing.