Heated floor in the bathroom: is it really useful in Montreal?
- Samuel Provencher
- 15 hours ago
- 9 min read
A considerable level of comfort that does not meet the same needs in all dwellings
In the depths of a Montreal winter, stepping onto cold ceramic tiles can be unpleasant. Heated flooring then seems like a clear improvement. It diffuses gentle warmth underfoot, makes the bathroom more inviting, and helps dry damp surfaces.
However, its installation represents an additional investment. It requires a system compatible with the floor, a thermostat, electrical work, and rigorous planning before the ceramic tiles are laid.
Is underfloor heating therefore essential in Montreal? Not necessarily. It becomes particularly advantageous in certain situations, while its usefulness is more limited in others.
How does an electric underfloor heating system work?
Cables installed under the coating distribute the heat
In a bathroom renovation, an electric heating system is generally the most practical solution. A heating cable is installed under the ceramic tiles, in a membrane, or in a layer of mortar designed for this purpose.
The cable transforms electricity into heat. This heat diffuses into the coating, then gradually rises into the room.
The system usually includes:
a heating cable or mat;
a compatible support or membrane;
a temperature sensor placed in the floor;
a thermostat;
a suitable power supply;
a device for protection against earth leakage.
The thermostat controls the surface temperature rather than leaving the cable running continuously. Programmable models can heat the bathroom before you wake up, lower the temperature during the day, and resume heating before you return.
Why is it particularly pleasant in Montreal?
Ceramics naturally retain a cool feeling in winter.
Ceramic and stone transmit heat quickly. This quality makes them efficient with a heating system, but also explains why they feel cold when no heat is being radiated from the floor.
In a city with a long heating season, the increased comfort can be felt for several months. The benefit is particularly noticeable in:
a bathroom located above a garage;
a ground floor apartment;
a basement;
an old house;
a room with several exterior walls;
a bathroom located away from the main heating system;
a room whose floor is built on a concrete slab.
Conversely, a small interior bathroom, surrounded by heated rooms and located on an intermediate floor, can still maintain a comfortable temperature. The heated floor remains comfortable, but it addresses more of a personal preference than a genuine problem with the cold.
Is this the main heating system?
In most bathrooms, it primarily provides added comfort.
An electric heated floor can warm the air in the room, but it does not automatically replace a baseboard heater, convector heater, or other heating appliance.
Its capacity depends in particular on:
of the area actually heated;
the power of the cable;
insulation;
heat loss;
the number of exterior walls;
the presence of a window;
of the desired temperature.
In a small, well-insulated room, it can make a significant contribution to heating. However, a large portion of the bathroom floor is often taken up by the vanity, toilet, bathtub, or shower. The available space for cables then becomes relatively limited.
The system should therefore be considered as a source of comfort, unless an assessment confirms that it can meet the heating needs of the room.
Where can the cables be installed?
Only the useful areas of the floor need to be heated.
The cables are not laid uniformly throughout the bathroom. They are generally installed in areas where people walk:
in the face of vanity;
between the door and the shower;
near the bathtub;
around the toilet, respecting the required clearances;
in the passages actually used.
They should not be located under fixed elements that could trap heat, in particular:
a vanity resting directly on the floor;
a bathtub;
a toilet;
a partition;
a permanent piece of furniture;
a device without lower clearance.
The layout plan must therefore be confirmed before calculating the cable length. A wall-mounted vanity unit can allow the heating to be extended under part of the unit, but this depends on the manufacturer's instructions and the available airflow.
A heating cable should never be shortened, crossed or arbitrarily brought closer together to use excess length.
Can the shower floor be heated?
Installation is possible with some systems, but not automatic.
Some systems allow for extended heating in the shower area. This option can make the floor more comfortable and speed up drying, but it requires a specific design.
In particular, coordination is needed:
the heating cable;
the slope of the shower;
the drain;
the waterproofing membrane;
the threshold;
the temperature sensor;
the applicable electrical requirements.
For example, the manufacturer Schluter recommends using separate cables for the shower and the rest of the bathroom , as well as a waterproofing membrane installed above the system in the shower area.
Therefore, adding a heating system to the shower should not be a last-minute decision. This decision must be made before ordering the cables and validated according to the chosen system and the applicable project requirements.
In many bathrooms, heating only the dry area already provides most of the desired comfort.
Which coating is best?
Ceramics and stone efficiently transmit heat
Porcelain, ceramic, and natural stone are particularly well-suited to underfloor heating. They conduct heat, withstand normal system temperatures, and distribute it evenly.
Other coatings may be compatible, but their maximum temperature must be checked. This is particularly the case for:
vinyl;
engineered wood;
laminate;
of certain composite materials;
glued coatings.
An insulating or excessively thick coating slows down heat transmission. A sensitive material can warp or discolor if the temperature exceeds recommended limits.
The choice of heating system and the choice of flooring must therefore be made together.
Is the support under the cable important?
The heat should be directed towards the room rather than towards the structure
Simply installing a cable under the ceramic tiles does not guarantee a rapid temperature increase. Some of the heat can still dissipate downwards, especially when the floor rests on a cold slab or an unheated space.
The performance then depends on the complete composition of the floor:
subfloor;
insulation;
membrane;
cable;
cement-adhesive;
ceramic.
On an uninsulated concrete slab, the system may take longer to heat the surface, as some of its energy first heats the mass of the concrete. A suitable insulation or thermal break solution can improve the response time, subject to height constraints.
In a wooden floor, the rigidity of the subfloor must also be checked. Heating does not compensate for movements that could crack the tiles or grout.
Some underfloor heating systems combine the cables with a decoupling membrane designed to protect the tiled assembly from differential movements of the substrate.
Does underfloor heating help control humidity?
It speeds up drying, but does not replace ventilation.
A warm floor dries faster after a shower. Water droplets and damp carpets don't stay on a cold surface as long.
This feature can improve comfort and reduce the feeling of persistent dampness. However, the evaporating water remains in the bathroom air and must always be removed through adequate ventilation.
Underfloor heating therefore does not replace:
a properly sized exhaust fan;
a waterproof shower;
a functional slope;
regular maintenance;
sufficient air circulation.
It helps to dry surfaces, but it does not solve a condensation or mold problem on its own.
How much electricity does it consume?
Consumption depends mainly on the surface area and operating time.
It is difficult to give a universal monthly cost. Two bathrooms of the same size can use the system very differently.
Consumption depends on:
the power of the cable;
of the heated area;
of the programmed temperature;
of the operating time;
floor insulation;
of ambient temperature;
of the coating's ability to transmit heat.
The system does not constantly consume its maximum power. The thermostat interrupts the power supply when the floor reaches the desired temperature, then reactivates it as needed.
Appropriate programming helps avoid keeping the floor hot all day. In a bathroom used in the morning and evening, you can anticipate these periods and reduce the temperature between them.
However, the floor has a certain inertia. Starting it as soon as you enter the room is generally not enough: you have to give it time to heat up the flooring.
Which thermostat should I choose?
Programming directly influences comfort and usage
A programmable thermostat is particularly useful in a bathroom. It allows you to set the temperature before use without running the system unnecessarily.
Depending on the model, it can offer:
daily schedules;
several temperature ranges;
a mode of absence;
a remote control;
a maximum limit for the coating;
a reading of consumption;
floor sensor regulation.
The sensor placed under the ceramic tiles measures the actual floor temperature. It protects the flooring and allows for more precise control than air temperature alone.
Some manufacturers supply two sensors. The second can be installed as a spare in the floor and left unconnected. If the primary sensor fails, the backup sensor can prevent the need to open the ceramic tiles.
When should the installation be scheduled?
The system must be integrated before the coating is laid.
The best time to install underfloor heating is during a complete renovation, when the old flooring has already been removed.
Advance planning is necessary:
the surface area actually heated;
the position of sanitary fixtures;
the cable route;
the location of the thermostat;
the electrical circuit;
the position of the sensors;
the final thickness of the floor;
the transition to the neighboring rooms.
Adding the system slightly increases the thickness of the assembly. This difference must be taken into account at the door threshold, around the drain, and under adjacent elements.
The cable must also be tested at the recommended stages: before installation, during installation, and before final covering. Once the ceramic is installed, repairs become much more difficult.
Who can make the connection?
Electrical work should be entrusted to a qualified professional.
The installation of the membrane and cable must follow the manufacturer's instructions. Connection to the circuit, thermostat installation, and electrical checks must be coordinated with a licensed electrical contractor.
In Quebec, electrical installation work must be carried out by a contractor holding the appropriate license and a member of the Corporation of Master Electricians of Quebec .
The electrician must, in particular, check:
the panel's capacity;
the system voltage;
the total power;
the required circuit;
electrical protections;
the positioning of the thermostat;
the results of the cable tests.
This coordination must take place before the walls are closed and the ceramic tiles are laid.
What constraints should be expected in a condo?
The electrical panel and the condominium rules must be checked.
In a condo, the installation of heated flooring generally only affects the interior of the unit, but it may require a new circuit or work on the electrical panel.
We need to check:
the available capacity of the panel;
the possible route of the power cable;
the rules for renovating the condominium;
requirements relating to electrical work;
restrictions on construction hours;
the acoustic composition of the floor.
If the bathroom is located on a concrete slab, the floor construction must also preserve the acoustic performance required by the building.
The heating system, the membrane and the coating must then be considered as a complete assembly.
How much does underfloor heating cost?
The price depends more on the configuration than on the total area
The budget includes several elements:
the membrane or the support;
the heating cable;
the thermostat;
the sensors;
the preparation of the subfloor;
electrical work;
the installation;
height adjustments.
A small bathroom is not always proportionally inexpensive, as it still requires a thermostat, a power supply and the intervention of various trades.
On the other hand, when the floor is already open and the ceramic tiles need to be replaced, adding heating makes much more sense than in a recently completed bathroom.
When is underfloor heating really useful?
Certain configurations allow you to take full advantage of it
Underfloor heating is particularly relevant when:
The bathroom is cold in winter;
the floor is located above an unheated space;
the room is located in the basement;
New ceramic tiles already need to be installed;
the occupants use the bathroom at regular times;
Morning comfort is a priority;
the project includes a complete renovation;
The house will be occupied long-term.
It is less of a priority when:
the room is already warm;
the traffic area is very small;
the floor does not need to be replaced;
the majority of the surface is covered by fixed elements;
the electrical panel offers little capacity;
The budget should first be allocated to waterproofing, plumbing or ventilation.
Underfloor heating is therefore rarely essential, but it is one of the improvements that occupants appreciate on a daily basis.
Have the project evaluated by BonBain
Determine if the comfort achieved justifies the installation
In Montreal, heated floors can significantly improve bathroom comfort for much of the year. However, their effectiveness depends on the room's location, insulation, available space, and intended use.
BonBain can integrate the system into the bathroom design, coordinate its installation with the plumbing and sanitary fixtures, and then plan the necessary work before the ceramic tiles are laid.
To have your project reviewed, fill out the BonBain free estimate request .
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