FAQ s
 
  • F.A.Q: ThermFloor Electrical Underfloor Heating Systems

    • Features of ThermFloor electrical underfloor heating systems and everyday questions and answers

    1. What is ThermMAT ?

    2. How simple is ThermMAT to install ?

    3. How Do I Choose the Correct Size of ThermMAT for my Installation ?

    4. What is ThermCABLE ?

    5. How simple is ThermCABLE to install ?

    6. Is it possible to estimate the running cost ?

    7. ThermMAT 160w/m or ThermMAT 120w/m ?

    8. How wide is ThermMAT ?

    9. How Safe is ThermMAT and ThermCABLE ?

    10. Is it necessary for an expert to install ThermMAT and ThermCABLE ?

    11. Will I need any other materials to install ThermMAT or ThermCABLE ?

    12. Can I tile directly on top of ThermMAT or ThermCABLE ?

    13. What type of control is required with ThermMAT and ThermCABLE ?

    14. How Can I Test My ThermFloor System ?

    15. Can I Install on any subfloor ?

    16. Will my floor level be raised ?

    17. What is the temperature of the tile surface ?

    18. ThermMAT or ThermCABLE ?

    19. Can ThermFloor systems be used for total heating in the room ?

    20. Is it possible to control the floor heating system ?

    21. How quickly will my floor get warm ?

    22. Have you any instructions for the tiler ?

    23. Why insulate ?

    24. What thickness of insulation board do you recommend ?

    25. Is ThermMAT and ThermCABLE Guaranteed ?

    26. Can ThermFloor systems be installed under laminate, wood or plastic floor ?
    1. What is ThermMAT ? - Top

    ThermMAT is a heating mat, with a 3mm thick twin wire heating cable pre-mounted onto commercial grade fiberglass mesh that holds the heating cable together to simplify installation.

    ThermMAT has a self adhesive side which is extremely sticky to allow easy fixing to the sub-floor. The adhesive extends to the cable loops that run along each side of the mat.

    All mats have been tested in accordance to National and International Standards for safety. Mats comply with rules regarding the EMC (Electro Magnetic Compatability) and fulfil the ICNRIP guidelines and regulations with regards to EMF (Electro Magnetic Fields).

    The ThermMAT heating element is produced with THREE layers of electrical insulation and earth braid, conforming to the most exacting specification in the industry, and is suitable for use in any room.

    Manufactured in a wide range of ready made sizes with the supply lead wire at one end only, it is supplied on a roll for quick and easy installation – this design offers maximum flexibility to the installer; easy to plan and easy to lay and suitable for large or small areas.

    • Perfect for applications in bathrooms, kitchens, conservatories etc.

    • Suitable for ceramic, natural stone, slate, marble, limestone, terrecotta etc.

    • 10 year warranty.

    • ThermMAT is available in two standard power outputs of 120 w/m² and 160 w/m²

    • ThermMAT rated at 160 w/m² is ideal for conservatory concrete floors and rooms where faster heat up is required.

    ThermMAT is easy to install and good for renovation projects, as well as new build.

    A full colour ThermFloor brochure is available on request.
    - Updated: October 9, 2005
    2. How simple is ThermMAT to install ? - Top

    Installing ThermMAT is ideal for the DIY enthusiast or approved installation contractor.

    The ultra thin profile of ThermMAT is suitable for renovation, as well as new build.

    Only a pair of household scissors are needed when cutting the fiberglass mesh. THE HEATING ELEMENT MUST NOT BE CUT.

    Each mat is fitted with a supply lead wire at one end only. You don’t need to worry about where the mat ends! Just cut the mesh and turn it any way to fit your floor space.

    ThermMAT has a self adhesive side which is extremely sticky to allow easy fixing to the sub-floor. The adhesive extends to the cable loops that run along each side of the mat.

    The heating elements can be easily detached from the fiberglass mesh to assist installation around shapes and obstacles.

    You can combine more than one size of ThermMAT to cover the total floor space and with multiple circuits the lead wires must be connected electrically in parallel.

    Once the position for the control has been decided the size of mat or combined sizes to match the room layout can be chosen from the chart provided.

    For example, for a heated floor area of 5m² you have the choice of using ThermMAT sized at 5m² or a combination of 4m² + 1m² or 3m² + 2m²

    Remember more than two mat sizes can be combined together if required.

    Full installation instructions can be downloaded on the website in pdf format.

    A 16 page A5 size installation instruction booklet is available on request.

    - Updated: October 9, 2005
    3. How Do I Choose the Correct Size of ThermMAT for my Installation ? - Top

    Plan the installation.

    Draw a general view of the room and mark the area which will be covered with heating elements. Take measurements of the room. Avoid heating under units and sanitary ware as this can cause heat blockage and it is unnecessary to heat these areas anyway.

    Always start by measuring the FREE floor area available to apply the heat.

    In a bathroom the FREE area is the floor area LESS the bath, shower, toilet, washbasin and any units.

    In a kitchen the FREE area is the floor area LESS the kitchen units and appliances.

    Select the size of ThermMAT below the actual FREE area available e.g. if the FREE area is 7.6m² you should select a 7m² pack, for 4.2m² a 4.0m² pack and so on.

    In each case check that the mat will fit into your room as it is not possible to cut the heating element.

    Bear in mind to leave a minimum 50mm unheated gap around the room perimeter when calculating the heated area.

    - Updated: September 19, 2005
    4. What is ThermCABLE ? - Top

    ThermCABLE is a twin wire heating cable supplied on a reel with the supply lead wire at one end only.

    The ThermCABLE heating element is produced with THREE layers of electrical insulation and earth braid. It is designed to meet European and International Class 2 safety standards, conforming to the most exacting specification in the industry, and is suitable for use in any room.

    • Perfect for applications where extra flexibility may be required with the layout, especially in smaller areas with obstacles, such as en-suites, shower rooms and bathrooms.

    • Suitable for ceramic, natural stone, slate, marble, limestone, terrecotta etc.

    • 10 year warranty.

    • ThermCABLE can be installed to match power outputs in the range 100 to 200 w/m².

    The dual wire construction ensures electro-magnetic emissions are practically eliminated making it safe for children to play on the heated floor.

    It is installer friendly with a 4m long supply lead wire at one end only.

    With ThermCABLE there is no need to get two ends of cable back to a termination point.
    - Updated: October 9, 2005
    5. How simple is ThermCABLE to install ? - Top

    Installing ThermCABLE is ideal for the DIY enthusiast or approved installation contractor.

    The ultra thin profile of ThermCABLE is suitable for renovation, as well as new build.

    ThermCABLE requires more time to install than ThermMAT but it can provide the installer with extra layout flexibility, especially in smaller areas with obstacles, such as en-suites, shower rooms and bathrooms.

    A table provides a guide to the floor area permutations at various watts density and cable spacing.

    You can combine more than one size of ThermCABLE to cover the total floor space and with multiple circuits the lead wires must be connected electrically in parallel.

    Once the position for the control has been decided the size of cable or combined sizes to match the room layout can be chosen from the table provided.

    Remember more than two cable sizes can be combined together if required.

    Full installation instructions can be downloaded on the website in pdf format.

    A 16 page A5 size installation instruction booklet is available on request.

    - Updated: October 9, 2005
    6. Is it possible to estimate the running cost ? - Top

    Yes

    The general rule of thumb is to compare the daily cost of running a ThermMAT or ThermCABLE system with the cost of a daily newspaper. In most cases it is much less !!

    There is a real pay-back with insulated floors in terms of the energy consumed.

    ThermFloor recommend the use of insulation in the floor and insulating backer board whenever possible.

    Insulation will improve the heating efficiency, provide faster heat up time and save energy.
    - Updated: October 9, 2005
    7. ThermMAT 160w/m or ThermMAT 120w/m ? - Top

    If the requirement is for under tile heating then it is easy to choose between 160w/m² and 120w/m²

    ThermMAT rated at 120w/m² is the safest solution for direct contact with a wooden subfloor.

    This situation is extremely common in many new homes and apartments and ThermMAT rated 120w/m² provides a perfectly heated tiled floor.

    ThermMAT rated at 160w/m² should always be installed on concrete floors, especially in a conservatory.

    ThermMAT 160w/m² provides a faster heat up than ThermMAT 120w/m².
    - Updated: October 9, 2005
    8. How wide is ThermMAT ? - Top

    When ThermMAT is run side by side, each run is designed to cover a width equivalent to approximately 500mm.

    For example, in a 4m² ThermMAT pack the roll is 8 metres long and this pack is designed to cover an area of 4m².

    - Updated: September 19, 2005
    9. How Safe is ThermMAT and ThermCABLE ? - Top

    Perfectly safe!

    All mats and cables have been tested in accordance to National and International Standards for safety. Cables and mats comply with rules regarding the EMC (Electro Magnetic Compatability) and fulfil the ICNRIP guidelines and regulations with regards to EMF (Electro Magnetic Fields).

    Heating elements are produced with THREE layers of electrical insulation and earth braid, conforming to the most exacting specification in the industry,

    Because of the dual wire construction of the heating element there is only one cold lead to connect and electro magnetic emissions are virtually eliminated making it safe for children to play on the heated floor.
    - Updated: October 9, 2005
    10. Is it necessary for an expert to install ThermMAT and ThermCABLE ? - Top

    Installation is ideal for either the DIY enthusiast or approved installation contractor.

    The electrical supply must be protected by a correctly sized RCD (Residual Current Device), either at the mains or a fused spur.

    The system connects to your household wiring and it is recommended the final mains electrical connection is made by a qualified electrician.

    A full set of installation instructions are provided with each pack and you can make a call to 0845 644 3632 for assistance Monday to Friday between the hours of 8.30am and 5pm.

    Full installation instructions can be downloaded on the website in pdf format.

    A 16 page A5 size installation instruction booklet is available on request.

    Care should be taken when planning the installation in larger floor areas due to the higher electrical loading required. A separate power supply may be needed.

    - Updated: October 9, 2005
    11. Will I need any other materials to install ThermMAT or ThermCABLE ? - Top

    Before installing ThermMAT or ThermCABLE you should prepare the subfloor. Clean the floor and prime with a coat of inexpensive PVA, a water based adhesive primer. This will also help the tile adhesive and/or levelling compound to bond with the subfloor.

    Any good tile or hardware outlet will supply PVA primer and it will cost less than £5 for one litre.

    ThermMAT has a self adhesive side which is extremely sticky to allow easy fixing to the sub-floor. The adhesive extends to the cable loops that run along each side of the mat.

    Flexible tile adhesive and fillers are required e.g. latex, acrylic or polymer based. These will compensate for any movement of the tiles and possible cracking caused through expansion and contraction. A flexible grout should also be used.

    Full installation instructions can be downloaded on the website in pdf format.

    - Updated: September 20, 2005
    12. Can I tile directly on top of ThermMAT or ThermCABLE ? - Top

    Using a flexible adhesive the tiling can be carried out as a single operation directly on top of ThermMAT or ThermCABLE.

    Allow a depth of adhesive sufficient to lay the tile and encapsulate the heating element with no air gaps.

    Always use a plastic trowel for a trouble free installation and to avoid damaging the heating element.

    ThermCABLE installations: take care not to dislodge any of the ThermCABLE from its fixed position when applying tile adhesive.


    - Updated: September 20, 2005
    13. What type of control is required with ThermMAT and ThermCABLE ? - Top

    ThermCONTROL

    ThermCONTROL is a digital programmable control suitable for flush mounting.

    Approved by design houses for looks it is available in white, silver or brass.

    ThermCONTROL is sold separately from ThermMAT and ThermCABLE in order to offer a choice of finish (white, silver or brass) and control operation (floor/room sensing combined or floor sensing only)
    - Updated: October 9, 2005
    14. How Can I Test My ThermFloor System ? - Top

    Follow the instructions provided.

    Basic electrical tests are required at the various stages of installation and the results should be recorded on the guarantee card provided.

    Check before installation, immediately after installing and before putting the heating into operation.

    Test for cable continuity and its resistance (ohms), as well as the resistance of the sensor cable.

    Also, measure the insulation resistance value as required by BS7671 - the minimum reading should be 10 megohms regardless of element length.

    Record the results on your guarantee card.

    Consult your electrician.
    - Updated: October 9, 2005
    15. Can I Install on any subfloor ? - Top

    Yes

    If the requirement is for under tile heating then it is easy to choose between 160w/m² and 120w/m²

    ThermMAT rated at 120w/m² is the safest solution for direct contact with a wooden subfloor and is the only option when the floor level is critical.

    This situation is extremely common in many new homes and apartments and ThermMAT rated 120w/m² provides a perfectly heated tiled floor.

    ThermMAT rated at 160w/m² should always be installed on concrete floors, especially in a conservatory.

    - Updated: September 19, 2005
    16. Will my floor level be raised ? - Top

    The ultra thin profile of ThermFloor systems is ideal for renovation, as well as new build.

    The heating element is only 3mm thick.
    - Updated: September 19, 2005
    17. What is the temperature of the tile surface ? - Top

    This is between 25-27°C in accordance with the BSI guidelines for comfort heating. BSI Code of Practice CP:1018 - Electric Floor Warming Systems specifies a maximum floor surface temperature of 27°C - Updated: September 19, 2005
    18. ThermMAT or ThermCABLE ? - Top

    ThermMAT is a heating mat with the heating element mounted onto a fiberglass mesh that holds the heating cable together to simplify installation. Without a doubt this is the easiest system to install.

    However, although ThermCABLE requires more time to install than ThermMAT, it can provide the installer with extra layout flexibility, especially in smaller areas with obstacles, such as en-suites, shower rooms and bathrooms.

    Cable systems are labour intensive and this problem increases with the size of the floor area, which can result in installation mistakes.

    Cable systems will generally require a cover of levelling compound prior to tiling because of the tendency for the cable to move during the tiling operation if it is not secured to the floor properly.

    However, it is easier to control the movement of the heating element in smaller areas. Also, when ThermFIX is used as a means of fixing the cable to the floor, the element cable can be made much more secure by this method compared to the fixing tape method.
    - Updated: October 12, 2005
    19. Can ThermFloor systems be used for total heating in the room ? - Top

    Yes, but it will depend on a number of factors such as the insulating properties of the room.

    For example, heat losses in conservatories are much greater than internal rooms. To achieve total heating in conservatories a cable in screed system is the most practical solution with the cable buried up to 50mm below the subfloor surface – and then it is only possible if the heat loss can be replaced and you have planned your floor levels accordingly: each installation is different.

    Thermfloor offer a design service for total heat requirements as the concept differs from comfort heating - simply call 0845 644 3632.

    Internal rooms with good quality 'u' values can achieve total heat with ThermFloor systems in the right circumstances.

    Some new apartments built to the latest building regulations are achieving total heat by installing less than 120 w/m².

    Each case is different and depends on the 'u' values, size, air movement, volume and position of the room.

    It is a fact, higher loadings do not mean you can automatically have total heating.

    Certainly not one system fits all.

    Thermfloor provide a design service for total heat - simply call 0845 644 3632 or email your details.
    - Updated: September 19, 2005
    20. Is it possible to control the floor heating system ? - Top

    Yes by ThermCONTROL.

    ThermCONTROL is a digital programmable control suitable for flush mounting.

    Approved by design houses for looks it is available in white, silver or brass.

    A programmable thermostat combines the time-clock function within the thermostat whilst offering additional features. The main feature of a programmable thermostat is the ability to set different temperatures at different times of the day – known as comfort levels.

    ThermCONTROL is sold separately from ThermMAT and ThermCABLE in order to offer a choice of finish (white, silver or brass) and control operation (combined floor/room sensing or floor sensing only)

    The ThemCONTROL range is rated at 13amps and this enables direct switching of loadings up to approx. 2900 watts.

    Higher loadings must be switched by a suitably rated contactor - or aternatively split the heating into more than one heating zone each operated by its own thermostat.

    In bathrooms the thermostat control MUST be mounted outside the bathroom.

    ThermCONTROL type CONTROLR2 offers a built in thermostat to measure the air temperature as well a 3m long remote probe sensor to measure the floor temperature.

    Air temperature control can be useful in a conservatory where the air sensor will override the floor heating control, helping to reduce the high air temperatures caused by a combination of floor heating and sunshine on the conservatory.

    ThermCONTROL type CONTROLR offers a 3m long remote probe floor sensor to measure the floor temperature.
    - Updated: March 21, 2007
    21. How quickly will my floor get warm ? - Top

    This depends on the subfloor and its insulation properties.

    A cement subfloor will be slower without a thermal barrier, as a percentage of the installed heat is absorbed into the floor (approx. 30% on a concrete floor without insulation).

    As a rule of thumb, a warm floor can be attained in less than forty minutes when insulating backer boards are installed.

    Insulated screeds and concrete floors will take up to 2 hours and uninsulated concrete floors may take anything up to 5 hours to reach the required floor temperature.

    To make the best use of the installed energy, insulation should be installed, either below the subfloor or as a layer of insulating backer board, OR BOTH.
    - Updated: September 19, 2005
    22. Have you any instructions for the tiler ? - Top

    If ThermMAT or ThermCABLE has been covered with a layer of flexible levelling compound prior to tiling, observe the drying time recommended by the manufacturers before tiling.

    A thin layer of levelling compound will provide protection for the heating mat or cable from mechanical damage. However, this step is not compulsory and you may decide to install the tiles in a single operation directly on top of the ThermMAT or ThermCABLE.

    It is OK to walk in stocking feet and kneel on the heating mat or cable, but avoid contact with sharp objects.

    DO NOT drop tiles onto the heating surface as this can damage the heating element.


    - Updated: September 19, 2005
    23. Why insulate ? - Top

    Systems rated at 160 w/m² are installed on uninsulated concrete floors with good results both in conservatories and internal rooms. However, due to the thermal dynamics involved, a cold uninsulated concrete subfloor will absorb up to 30% of the heat load down into the floor.

    Without insulation the heat up rate is slower and running costs higher. It is a fact however, many installations have critical floor levels and a layer of insulation, just 10mm, is not practical.

    To make the best use of the installed energy, insulation should be installed, either below the subfloor or as a layer of insulation backing board on top of the subfloor, OR BOTH.

    There is a real pay-back with insulated floors in terms of energy consumed.

    - Updated: September 19, 2005
    24. What thickness of insulation board do you recommend ? - Top

    This can be restricted by the floor level of your installation.

    10mm is fine in most cases and is our most popular size direct from stock.

    The time to heat up a tiled floor will hardly be noticeable, whether you use a 10mm board, 20mm board or thicker board.

    - Updated: September 19, 2005
    25. Is ThermMAT and ThermCABLE Guaranteed ? - Top

    All systems are backed by a manufacturers 10 year guarantee.

    Ask your installer to complete the guarantee card supplied with your system.
    - Updated: September 19, 2005
    26. Can ThermFloor systems be installed under laminate, wood or plastic floor ? - Top

    Yes, but not directly under !

    Constant wattage systems can damage these floor specifications, with a few exceptions. In each case the electrical loading and screed preparation is critical.

    This is a common area of floor heating design overlooked by many manufacturers.

    Please consult Thermfloor for responsible advice based on worldwide experience.

    Thermfloor provide full design and engineering support on all applications - simply call 0845 644 3632 or email: sales@thermfloor.co.uk
    - Updated: September 20, 2005

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