Bostik Heatstep Mat Installation Manual
You are required to thoroughly read all installation instructions and product safety information before beginning the installation of this product. FAILURE TO COMPLY WITH PROPER INSTALLATION AND MAINTENANCE INSTRUCTIONS COULD RESULT IN PROPERTY DAMAGE, PERSONAL INJURY AND/OR DEATH. Bostik is not responsible for damages resulting from improper installation and/or maintenance.
Welcome to HeatStep?!
HeatStep? floor heating mats are a simple way to heat an indoor space. This instruction manual is provided as a guide to installing HeatStep? Mats, including design considerations, installation steps, limitations, precautions, and floor covering guidelines.
Specifications for HeatStep? Mat:
HeatStep? Mat is a complete heating mat consisting of a series heating wire and a power lead for connection to the electric power supply. The heating wire length cannot be cut to fit.
Watts: 12 W/sqft (41 Btu/h/sqft)
Maximum circuit load: 15 A
Maximum circuit overload protection: 20 A breaker
Minimum bend radius: 1 inch
Maximum exposure temperature: (Continuous and storage) 194°F (90°C)
Minimum installation temperature: 50°F (10°C)
Installation must be performed by qualified persons, in accordance with local codes, ANSI/NFPA 70 (NEC Article 424) and CEC Part 1 Section 62 where applicable.
Prior to installation please consult the local codes in order to understand what is acceptable. To the extent this information is not consistent with local codes, the local codes should be followed. However, electrical wiring is required from a circuit breaker or other electrical circuit to the control. It is recommended that an electrician perform these installation steps. Please be aware local codes may require this product and/or the control to be installed by an electrician.
Expected floor temperature
Heating performance is never guaranteed. HeatStep? Mat is designed to deliver 12 W/sq.ft. The floor temperature attainable is dependent on how well the floor is insulated, the temperature of the floor before start up, and the overall thermal drain of the floor mass. Insulation is required for best performance. Refer to Phase 5 for important design considerations.
Phase 1: Designing the System
HeatStep? Mat should be installed in all interior floor areas intending to be warmed. It cannot be used for exterior applications, snow melting, in or on walls, or in ceilings. In many applications it can be used to heat the room but an accurate heat-loss calculation must be made to determine if enough heat will be provided to match the heat loss.
- Heat will not radiate beyond about 1-1/2" on either side of the heating wire, therefore consistent coverage is important.
- install heating wire within about 1-1/2" to 2" from a counter or vanity in the kick-space to ensure warmth in this area.
- install the heating wire underneath cabinets or fixtures having no floor clearance or inside a wall. Excessive heat will build up and cause damage.
- run the heating wire into small closets or other confined areas where excessive heat will build up.
- install the heating wires closer than 6" from toilet rings to avoid possible melting of wax rings.
- directly cross expansion joints.
- place the heating wire any closer than 4" from other items such as forced air ducting or potable piping to avoid overheating them.
- HeatStep? Mat must be laid in a manner to prevent surface obstructions being placed directly over the mat location. Failure to do so will result in capturing heat and may allow potential damage from mounting brackets, bolts, or similar penetrations associated with pedestals, support columns, walls, or similar.
- Install the heating wires 4" to 6" away from the perimeter walls of the room. Make sure the heating wire will not be located underneath finish trim.
- The heating wire and factory splices must be completely embedded in the thin-set. Only the power lead may exit the thin-set and enter the wall. Pull power leads through UL Listed conduit to a UL Listed junction box or the control box.
Multiply the heated area square footage calculated in Step 1.1 by 0.90 to allow 4" to 6" spacing around the edges of the floor area. Use this resulting square footage to select the appropriate mats from Table 2 on page 5.
- Do not exceed 15 amps at 120 VAC (1800 watts) or 15 amps (3600 watts) at 240 VAC through a single HeatStep? control or HeatStep? Relay.
- Select either 120 VAC or 240 VAC depending on the power available. DO NOT mix voltages on the same HeatStep? control if more than one mat is to be installed to cover an area.
- Load no more than 12 amps on a 15-amp circuit breaker, or 15 amps on a 20-amp circuit breaker.
- If the area requires more than 15 amps to be controlled by one thermostat use HeatStep? Relays to take the additional amp load.
- See the Wiring Diagrams in Appendix for further information.
If the exact size of product calculated is not found in the selection Table 2 on page 5, it may be necessary to adjust the warming area(s) or select the . Remember, the heating wire must never be cut shorter to fit, and must be completely embedded in thin-set, thick-set, or self-leveling mortar. Failure to do so may result in damage to the product. Do not select a product larger than necessary.
Make sure proper subfloor materials are selected in accordance with the construction and floor covering requirements. Use of a moisture barrier, an anti-fracture membrane, backerboard, or other materials are recommended when installing tile or other stone floor covering.
Pay careful attention to the total amps when selecting multiple mats to make sure the controls, circuit breaker panel, and all wiring have the proper capacity. Design circuit protection and wiring to handle 125% of total amp load.
Phase 2: Preparations
Before installing HeatStep? Mat, make sure to fully inspect the products and carefully plan the site.
- HeatStep? thermostat control with floor sensor. The HeatStep? control is listed separately from the HeatStep? Mat. - 20-amp circuit breaker - UL Listed electrical box (extra deep) for the control; single-gang (not a gangable type) for one or two mats or 4"-square deep box with a single-gang "mud ring" cover - 4" junction box with a cover (if needed) - Flexible or rigid UL Listed conduit (for new construction) - 12-gauge or 14-gauge electrical wiring cable (consult local code). - Wire nuts if using an additional junction box - Nail plate
- Digital multi-meter for ohms testing;
must read up to 20,000 ohms to measure sensor - Drill with 1/2" & 3/4" bits - Hammer and chisel - Wire strippers - Phillips screwdriver - Fish tape - Hole saw - Floor covering installation tools
Table 2 (HeatStep? Mat sizes)120 VAC
2 ft Wide
|Mat Square Footage||Mat Size (W x L)||Model Number||Amp Draw||Ohms|
|30||2' x 15'||K640115||3.0||34-42|
|40||2' x 20'||K640120||4.0||25-32|
|50||2' x 25'||K640125||5.0||20-26|
|60||2' x 30'||K640130||6.0||17-21|
|70||2' x 35'||K640135||7.0||14-18|
It is important to select the proper sized HeatStep? Mat for the given area. HeatStep? Mat can not be cut shorter in order to fit a given area. Doing so will damage the heating wire and will prevent the system from working.
INSPECT MAT, CONTROL, and SENSOR
Remove the Mat, HeatStep? control, and HeatStep? sensor from their packages. Inspect them for any visible damage and verify everything is the correct size and type according to the plan and the order. Do not attempt to install a damaged product.
Record the product information in Table 4. Give this information to the homeowner to keep in a safe place.
Do not remove this nameplate label. The electrical inspector will need to see this.
Use a digital multi-meter set to the 200Ω or 2000Ω (2kΩ) range to measure the resistance between the conductors of the mat power leads. Record these resistances in Table 4 under "Out of the box before installation".
Readings between the Black and Ground and the White (or Blue for 240 VAC) and Ground power lead wires should measure "open", or "O.L", or the same as displayed when the test leads are not touching anything.
Measure the resistance between either of the white or black leads and ground lead. This measurement should be "open", usually indicated by an "OL" or a "I". This is the same as displayed when the test leads are not touching anything.
If there is any change in the reading, record this information and contact the factory before continuing. This could indicate damage, test lead problems, or a number of other issues. Try "pinning" the test leads to the cable lead wires against a hard non-metal surface if the readings continue to fluctuate.
Change the meter to the 20,000 ohms (20 kΩ) range. Measure between the lead wires of the HeatStep? sensor. This resistance varies according to the temperature sensed. Table 3 provides approximate resistance-to-temperature values for reference.Table 3 (floor sensor resistance values)
Table 4 - HeatStep? Mat Resistance Log
|Mat 1||Mat 2||Mat 3|
|Mat serial number|
|Mat model number|
|Mat resistance range|
|OUT OF THE BOX BEFORE INSTALLATION|
|Mat white to black|
|Mat white to ground|
|Mat black to ground|
|AFTER MAT IS SECURED IN PLACE|
|Mat white to black|
|Mat white to ground|
|Mat black to ground|
|AFTER FLOOR COVERINGS ARE INSTALLED|
|Mat white to black|
|Mat white to ground|
|Mat black to ground|
|Retain this log to retain the warranty! Do not discard!|
Phase 3: Electrical Rough-in
Circuit Breaker (Overcurrent Protection)
HeatStep? Mat(s) must be protected against overload by a circuit breaker. GFCI type (ground fault circuit interrupter) or AFCI type (arc-fault circuit interrupter) breakers may be used if desired, but are not necessary.
The rating of the breaker (see Table 5) is determined by the amp draw of the heating mats (see Table 2 or the Nameplate Label). If multiple mats are to be controlled by one HeatStep? control, total their amp draws. If this total exceeds 15 amps, an additional breaker and control will be required. The total amps on each breaker can not exceed 15 amps. Do not use breakers rated over 20 amps.
|Circuit Breakers and Supply Wire|
|120||up to 12 amps||14||1||SP||15 or 20 A|
|120||up to 15 amps||12||1||SP||20 A|
|240||up to 12 amps||14||1||DP||15 or 20 A|
|240||up to 15 amps||12||1||DP||20 A|
** SP= single-pole, DP=double-pole
It may be possible to tap into an existing circuit as long as there is adequate capacity for the mat(s) and any additional appliance, such as a hair dryer or vacuum cleaner. Avoid circuits which have lighting, motors, exhaust fans, or hot tub pumps due to possible interference.Install an extra-deep single-gang box if connecting one or two cables to the control. Use a 4"-square deep box with a singlegang mud ring cover if connecting three cables, because the extra room is needed for the wire, wire nuts, and control.
Install Electrical Boxes
Install an extra-deep electrical box for the HeatStep? thermostat. Follow the instructions included with the HeatStep? control for complete information on location and wiring.
Install an extra-deep electrical box for any HeatStep? Relay(s). The HeatStep? Relay is used when more than 15 amps must be controlled by one HeatStep? thermostat. Follow the instructions included with the HeatStep? Relay for complete information on location and wiring.
If a mat is to be located so its Power lead is not long enough to reach the HeatStep? control or HeatStep? Relay directly, a junction box must be installed. Do not attempt to make a connection to other wiring without a junction box. Use a standard junction box with a cover, mounting it below the subfloor, in the attic, in the wall, or in another location easily accessible after all coverings are complete. If the HeatStep? control sensor wire is not long enough to reach the HeatStep? control directly, it may be extended. A junction box may be required by local code to make this connection. Follow the installation instructions included with the HeatStep? control for details.
For construction with an existing wall or where the wall is covered, cut the necessary openings to mount the electrical boxes listed above. Wait to install the boxes until all wiring is fed into these locations to make it easier to pull the wire.
Bottom Plate Work
Drill or chisel holes at the bottom plate as indicated. One hole is for routing the power lead conduit and the other is for the thermostat sensor. These holes should be directly below the electrical box(es).
Install Power Lead Conduit and Thermostat Sensor
Power Lead Conduit:
The shielded power lead can be installed with or without electrical conduit (recommended for added protection against nails or screws) depending on code requirements. Remove one of the knock-outs in the electrical box to route the power lead. If electrical conduit is not required by code, install a wire collar to secure the power leads where they enter the box. If conduit is required by code, install 1/2" (minimum) conduit from the bottom plate up to the electrical box. For multiple power leads (multiple mats) install 3/4" conduit.
The HeatStep? control sensor can be installed with or without electrical conduit depending on code requirements. Conduit is recommended for added protection against nails or screws. Do not place the sensor in the same conduit as the power leads to avoid possible interference. Open a separate knock-out in the bottom of the thermostat box. Feed the sensor (and conduit, if used) through the knock-out, down through the cut-out in the bottom plate, and out into the floor where the heating mat will be installed. If the sensor wire needs to be secured to the wall stud, wait until after the mat and sensor are completely installed on the floor.
Install appropriate 12 or 14 AWG electrical wire from the circuit breaker or branch circuit source to the HeatStep? control electrical box (and HeatStep? Relay box(es) if needed) following all codes, see Table 5.
If HeatStep? Relay(s) are used, feed appropriate wire (see HeatStep? Relay installation manual for size and type) between the HeatStep? Relay(s) and the HeatStep? control.
Conduit enclosing power lead.
Phase 4: Mat Installation
Bottom Plate Work
The floor must be completely swept of all debris including all nails, dirt, wood, and other construction debris. Make absolutely sure there are no objects on the floor which might damage the Mat wire.
Follow instructions for subfloor prep for Bostik SL-150?, WebCrete® 95, WebCrete® 98 or Ultra Finish?.
Make sure all of the correct materials have been purchased. A general list of materials is found at the beginning of this manual.
Verify the amount of mat supplied is the proper size for the area to be heated before beginning the installation. Verify thermostat location.
Position the Power Leads
Carefully cut the tie binding the power lead coil. Do not nick the braid covering the power lead.
Place the mat on the floor to ensure the power lead will reach the HeatStep? control electrical box or junction box location.
If the power lead will need to cross a long distance to reach the control location, it may be possible to cut the mat mesh and pull loose the length of heating wire needed.
Make sure the power lead factory splice is to be completely flat and in the floor mortar, not in the wall.
Test Fit the Mat
Roll out the mat, flipping it as needed to cover the intended area. This is very important to ensure proper fit before proceeding. If there is too much mat for the area it cannot be cut shorter and heating wire cannot be routed into a wall, under baseboards, or other similar areas. All heating wire must be embedded in the floor mortar.
Install the mat approximately 4"-6" away from walls, showers, tubs, drains, etc. and 6" from a toilet wax ring. Install in-line with vanity and counter areas. Install roughly 20" from back wall in toilet area.
leave gaps between the mats. The heat will conduct only about 1-1/2" from the heating wire. Mat should be installed continuously across the floor. Never install mats in a fashion causing the heating wires to be any closer than 2" from each other or to overlap.
To warm the maximum amount of floor area, it may be necessary to make the mat(s) fit odd-shaped spaces, fit into corners, and work around angles and built-ins. See Table 6 for technique examples and the Appendix for full layouts, additional techniques, and cautions.
Secure the Mat to the Floor
After test-fitting the mat and deciding what technique will be used to help fill any odd spaces, carefully cut the mesh where needed.
Lay the mat down flat. Ensure it fits well and has no folds or large ripples.
IMPORTANT: Securing the mat as flat as possible will help make a smooth surface for spreading mortar.
Secure the mat to the flooring using the double-sided tape supplied in the installation kit. Apply a length of the tape to the floor at each end of the mat and every 12" to 24" (30 cm to 60 cm).
If an area of mesh does not lay flat enough, use hot-glue, or pneumatically applied staples to help. This may be necessary at the ends of the mat. If staples are used, 3/8" x 1/4" chisel type are recommended. Do not staple closer than 1/4" (7 mm) from the heating wire. Be very careful not to damage the heating wire.
staple or apply tape over the heating wire. Damage can result.
use nails, duct tape, other types of tape, or other unapproved fasteners to hold the heating wire or mesh in place. Damage can result.
Use a digital multi-meter to measure the resistance between the conductors of the power leads again. Record these resistances in Table 4 under "After mat is secured in place".
Connect the Wire Fault Detector to the mat power lead. If multiple mats are used, connect them to the Wire fault detector in series (white-to-black). Only one white, black, and ground lead should be connected to the Wire fault detector. Refer to the Appendix for Wire fault detector wiring diagrams.
Feed the power leads through the conduit to the control electrical box, leaving at least 6"-8" of free power lead. Chisel a slot in the floor to recess the factory splice level with the heating wire. Secure the factory splice with hot glue so it cannot be pulled into the conduit.
It may be necessary to use a metal nail plate to protect the power lead and sensor wire as they transition into the wall. This will help prevent nail penetrations from drywall and baseboards trim.
Feed the sensor wire through the sensor conduit, leaving at least 6"-8" of free lead length at the control electrical box. Weave the sensor at least 1' into the mat area, halfway between the heating wires, and secure it using hot glue. Do not cross the heating wires. It may be necessary to chisel a small section of the subfloor to accommodate the sensor, depending on the thin-set thickness being used.
Top-Down view of HeatStep? Mat and the sensor entering wall.
Note: Acceptance of this application must be verified by the local inspector or authority having jurisdiction (AHJ).
- Refer to diagrams in the Appendix.
- Never install Mat in shower walls (or any other wall).
- Never make a field splice to mats installed in a shower.
- Use the double-sided tape or hot-glue to secure the mat. Do not use staples or anything that will damage any waterproofing membrane.
- Make a 1" wide notch in the curb to embed the heating wire. Ensure the wire is not pinched or bent sharply. Do not run the heating wire through a non-masonry curb, causing it to overheat. Locate power lead and factory connection to heating wire at least 1' the shower area.
- Embed mats in mortar and install only under tile, stone, brick, or other masonry surface, per this instruction manual.
- Never begin the mat in a shower. The connection between the power lead and the heating wire must be fully embedded in mortar and located at least 1' (304.8 mm) away from shower openings and other areas normally exposed to water.
- Mat controls must be located at least 4' away from shower openings. Controls cannot be exposed to water or touched by a person while in the shower area.
- All grout seams should be sealed after the mortar and grout has completely cured.
- As an option, consider installing a dedicated mat in the shower area, separate from the rest of the floor. This will increase control options, allowing less floor to be warmed when the shower is not required. It will also allow for better isolation of the shower area in the off-chance a problem occurs.
Take photographs of the mat installation. This can be very useful later during remodel work to help avoid possible wire damage. Keep the photos with this installation manual and provide to end user upon completion.
Phase 5: Floor Coverings
It is recommended to consult with professional flooring installers to make sure proper materials are used and proper installation techniques are followed. Please note, this installation manual is not a structural or a floor covering installation manual and is intended only for general guidance as it applies to the HeatStep? Mat product.
When installing tile or stone, the Tile Council of North America (TCNA) guidelines, National Tile Contractors Association (NTCA), or ANSI specifications should be followed as a minimum standard.
Use Bostik SL-150?, WebCrete® 95, WebCrete® 98 or Ultra Finish?. Do not use water-based multi-purpose materials when installing a radiant product.
Do not use solvent based adhesives or pre-mix mortars because they are not as heat resistant and do not conduct heat well.
Select the proper size trowel for the installation of tile or stone. We recommend a minimum 3/8" x 1/4" trowel. This trowel works well for most ceramic tile. A thicker thin-set can be used if required. Select the thin-set thickness in accordance with the floor covering requirements.
For additional information on tile installation, please contact TCNA at 864-646-8453 or visit their web site at www.tileusa.com, or contact NTCA at 601-939-2071 or see their web site at www.tile-assn.com
When installing floor coverings other than tile or stone, follow industry and/or manufacturer's recommendations. Ensure the mat is first covered with a layer of SL-150? self-leveling cement based mortar, letting it cure fully before applying any surface underlayment, floating wood or laminate flooring, carpet, etc. The combined R-values of all floor coverings over the mat should not exceed R-3. Higher R-values will diminish performance. Consult the floor covering manufacturer to verify compatibility with radiant electric heat. Also, make sure nails, screws, or other fasteners do not penetrate the floor in the HeatStep? Mat area. The wire can easily be damaged by fasteners penetrating the floor.
All floor coverings must be in direct contact with the cement-based mortar encasing the mat. Do not elevate the floor above the mortar mass. Do not install 2" x 4" wooden nailers (sleepers) on top of a slab for the purpose of attaching hardwood. Any air gap between the heating mat and the finished floor covering will drastically reduce the overall output of the heated floor.
Care should be taken when laying area rugs, throw rugs, and other surface products on the floor. Most products are okay to use, but if in doubt, consult the product manufacturer for compatibility. Do not use rubber backed products that may degrade or very heavy rugs that will trap heat. Be careful not to place a rug over the area where the sensor tip was placed, causing false thermostat readings.
When placing furniture make sure an air clearance of at least 1-1/2" is available. Furniture able to trap heat can damage the heating system, the flooring, and the furniture over time.
Use a digital multi-meter to measure the resistance between the conductors of the power leads again. Record these resistances in Table 4 under "After floor coverings are installed".
Type of Construction
Thin-set and thick-set (self-leveling) mortar applications are illustrated to the right.
- If a backer board or plywood sheeting is used to strengthen the floor, or if the mat will be placed directly onto the slab, install mat in the thin-set mortar bond coat above these materials.
- If a thicker mortar bed, or self-leveling concrete, is used to strengthen the floor, mat can be installed in either the mortar bed (dry-set) or in the mortar bond coat directly below the tile or stone.
HeatStep? Mat is generally installed above the self-leveling mortar in a thin-set bond coat. Use plastic lath instead of the typical metal lath when installing in a self-leveling layer.
Self-leveling Mortar Applications:
These are appropriate applications if installing engineered wood, vinyl, laminate, or carpet floor coverings. Attach the mat to the subfloor or slab, then pour self-leveling mortar 3/8" to 1/2" thick. Install floor covering after the mortar has cured.
Isolation Membrane: Install the mat above the membrane, whenever possible, unless recommended otherwise by the membrane manufacturer.
Insulation: Insulation dramatically enhances the performance and efficiency of floor-warming systems. Do not install rigid insulation directly above or below backer board or mortar.
Mosaic Tile: When installing mosaic tile, it is recommended to apply a two-step process. First, embed the mat in a thin self-level mortar bed (1/4"-3/8"), then thin-set the mosaic tile according to typical practice.
Expansion Joints: Do not install heating mats through an expansion joint. Install mats right up to the joint, if necessary, but not through the joint.
DOUBLE-PLYWOOD OVER FRAME FLOOR
DOUBLE-PLYWOOD OVER FRAME FLOOR
DOUBLE-PLYWOOD OVER FRAME FLOOR
Phase 6: Control Installation
Install the Controls
If it has not already been done, install an electrical box for the HeatStep? control and HeatStep? Relay. Do not forget to attach a single-gang mud-ring to mount the HeatStep? control if a 4" square box was used. See Phase 3 for details.
Refer to the wiring diagrams in the Appendix of this manual for typical configurations.
Read and follow the instructions included with the HeatStep? thermostat and HeatStep? Relay for complete connection instructions, requirements, and mounting.
Make any final connections to the circuit breaker or branch circuit source.
System Start Up
After all controls are installed, do not energize the system, except to briefly test operation of all components (no longer than 10 minutes). Do not put the system into full operation until the tile or flooring installer verifies all cement materials are fully cured (typically two to four weeks). See instructions for recommended curing time for the cementitious products used.
Note: Most laminate and wood floor manufacturers specify their flooring should not be subjected to temperatures over 82° to 84°F (27° to 28°C). Check with the flooring dealer or manufacturer and set the thermostat Floor Limit temperature appropriately.
Refer to the installation sheets provided with the controls for proper setting. The system should now operate as designed. Please leave this instruction manual, HeatStep? control instructions, and copies of photos of the installed heating system with the end user.
Place this warning label (provided with the product) on the electrical panel and indicate the circuit breaker number that supplies the radiant heating. Also, place the label indicating "Radiant Floor Heating" on the control.
General layout of the HeatStep? Mat installation
If problems arise with the HeatStep? Mat or its related electrical components, please consult this troubleshooting guide. If not qualified to perform electrical work, it is highly recommended a qualified, licensed electrician be hired
Any electrical troubleshooting work should be performed with the power removed from the circuit, unless otherwise noted.
Although this troubleshooting guide is provided to assist with problems experienced with a HeatStep? system, results are never guaranteed. Bostik does not assume any liability or responsibility for damage or injury that may occur from using this guide. If problems with the system persist, call the manufacturer.
|An analog meter (using a moving needle) was used to take the reading.|
|If measurement shows an open or short circuit, the Heating Wire has been damaged.|
|If measurement is just a little low or high, room temperature has affected the resistance.|
|The resistance measurement could be from more than one mat wired in series, or wired in parallel. Either will provide false resistance readings.|
|Make sure resistance measurements are for only one mat at a time.|
|Mat has been damaged.|
|GFCI has tripped, indicated by a light or "GFCI TRIP" on the control.|
|Incorrect voltage supplied, or mismatched electrical components used.|
|Uninsulated concrete slab floor.|
|Mats are wired in "series" or "daisy chained" (end-to-end).|
|Incorrect wiring. The control was "bypassed" when it was wired to the power supply.|
|If a programmable control, the programming may be incorrect.|
|Incorrect voltage supplied, or mismatched components used.|
|Floor sensor is not wired properly, or is not working properly.|
|Loose connection(s) on line side and/or load side of control.|
|No power is supplied.|
|An electric motor or a ballasted light source is sharing the circuit with the mat.|
System is an ISO 9001:2008 registered
facility through LRQA.
(800) 7BOSTIK / (800) 726-7845