Underfloor heating in the bathroom is an excellent idea for many reasons. However, there are many myths about it that have mixed with facts. Therefore, we decided to dispel the most common doubts about installing underfloor heating in the bathroom. See what the reality is.
Find out when underfloor heating in the bathroom works well and when you may need to pay attention to additional aspects. It’s worth knowing.
To start with: many people, when talking about underfloor heating, think of water-based underfloor heating. However, there is also the possibility of installing electric mats under the bathroom floor - electric underfloor heating. Heating mats are an interesting and quite flexible solution, as they can even be installed in walls, though this is rarely practiced. If it’s not a newly built house and planning the heating layout precisely is challenging, and changes would require significant renovation, electric underfloor heating for the bathroom doesn’t seem like a bad idea.
However, there are several reasons why water-based underfloor heating in the bathroom is a better and safer solution. In the event of a heating mat failure, you would have to remove the tiles, which would be very costly. Pipe failures in underfloor heating are much rarer; in fact, you hardly hear about them.
✅ Can underfloor heating alone heat the bathroom? Or should an additional radiator be installed?
Generally, underfloor heating is sufficient in the bathroom without radiators. Whether underfloor heating will suffice in the bathroom depends mainly on the floor area that remains uncovered after installing a bathtub or shower tray, or possibly furniture. You shouldn’t consider the entire floor area because underfloor heating is usually not installed under bathtubs, shower trays, or fixed cabinets.
☑️ You don’t need a large bathroom for underfloor heating to provide full thermal comfort. Only very small bathrooms (e.g., just a few square meters) and - in old buildings - might require an additional radiator. In new buildings, where heat losses are very limited, underfloor heating is often sufficient even for heating a small room with just a toilet.
Exceptions can be homes in old buildings, which generally have significant heat losses. Speaking very generally, underfloor heating works better in well-insulated buildings with low heat loss. If you decide on underfloor heating in a bathroom in an old building and it’s not very large, be sure to consult an expert to see if underfloor heating alone will suffice, to potentially plan for adding a radiator in advance.
✅ Is a radiator in the bathroom still useful if we already have underfloor heating?
Yes, it is worth installing a radiator additionally - but it’s not about enhancing the efficiency of the underfloor heating in the bathroom. It’s more about having a place to hang a towel after a bath, where it will dry quickly. This definitely improves user comfort because you always have a dry towel available.
You can opt for an electric radiator (there are interesting solutions with ladder radiators with a thermostat - which can turn off automatically after reaching the desired temperature in the bathroom).
The latest trend in radiators for bathrooms with underfloor heating is ladder-type radiators, which are great for drying towels. However, there’s the issue of the radiator’s supply temperature, as radiators are generally associated with a higher supply temperature than underfloor heating.
If you have a new building and have opted for underfloor heating throughout the house, your heating device - such as a condensing boiler or a heat pump - has excellent conditions for economic operation and will work very efficiently. This is because underfloor heating only requires heating water to a temperature of 30-35°C. The presence of a radiator - powered by a higher temperature, somewhat disrupts the entire plan of super energy-efficient heating. Below we explain why there is no need for this.
✅ Does a ladder-type radiator - powered by the same temperature as underfloor heating in the bathroom - make sense? Can a radiator work on the bathroom's underfloor heating loops?
A radiator in a bathroom with underfloor heating serves only an additional function, intended for drying towels and potentially as a decorative element. The primary heat source in this room should be the floor, which is sufficient - there’s no reason to treat the radiator as a heating element for the room itself. We assure you that supplying such a radiator with the same temperature as the bathroom’s underfloor heating is enough. The radiator does not need to be hot to effectively dry towels; it just needs to be warm. This may evoke mixed feelings in people with experience living in old buildings, but we guarantee that it works perfectly.
☑️ Important tip - if you decide to have a radiator in a bathroom with underfloor heating, powered by the same temperature as the floor, it is possible to run it on the same heating loop as the floor. However, it’s worth remembering to place the radiator at the beginning of the loop, so that after heating the radiator, the water flows to the floor. This will ensure that the water reaching the radiator is not too cool and is heated to a minimum of 30°C - which is sufficient to dry towels or even laundry on the radiator. For those worried that the radiator will use up the heat and the underfloor heating won’t manage, we assure you that this is a myth without practical basis. Heating operates continuously in winter, and there is absolutely no risk in a heated home. For such a danger to actually occur, the radiator would have to be located in a completely unheated room or outside.
✅ Does underfloor heating under the shower work - when can you think about a warm floor in the shower cabin?
Underfloor heating under the shower, feeling the warm floor under your feet while taking a shower, especially in winter, greatly increases comfort. Underfloor heating under the shower is entirely feasible and possible - you just need to plan it well.
We have already mentioned that underfloor heating is not installed under the shower if there is a shower tray. Heating loops are not usually installed under shower trays, just like under bathtubs.
However, if you opt for a shower cabin with a linear drain - meaning there are tiles under the shower - it’s definitely worth running the underfloor heating pipes there. This is highly recommended as it increases the heating surface of the floor.
❌ Important note - if you have a linear drain with a wet-type siphon, the floor loop cannot run in close proximity to the drain. The heat from the loop will warm the water in the siphon, causing it to evaporate. As a result, the siphon may not function properly at times, and unpleasant odors from the drain pipe may be noticeable in the bathroom. The underfloor heating loop should be at least 20 cm away from the siphon. With dry siphons, this issue doesn’t arise, and the loops can be installed without restrictions.
Some people might consider installing electric underfloor heating under the shower. This seems particularly attractive if traditional underfloor heating is not being installed or if it’s not present in the house, so laying an additional underfloor heating loop to the existing system would be problematic. Meanwhile, a warm floor in the shower is certainly desirable. Unfortunately, we advise against this idea.
Various situations can occur, such as malfunctioning heating mats or their failure after a couple of years of use. Even if the product is under warranty, the fact remains that your shower cabin would need to undergo a significant renovation, involving tile removal, etc. The risk is not large, but such cases do happen because even the best workmanship and materials cannot always prevent defects. In our subjective opinion, electric underfloor heating for the shower is a bad idea, but if you decide to go for it, use high-quality materials.
To summarize, the places in the bathroom where underfloor heating should not be installed are as follows:
✅ What is the cost of installing water-based underfloor heating in the bathroom?
To get straight to the point, as this question always arises in the end. For water-based underfloor heating - which is traditional and arguably the best for the bathroom - the material cost is between 30 to 70 € per square meter. This includes insulating materials and loops. However, you also need to account for installation costs, which can vary by region. It will also depend on whether the professional is working on just the bathroom or the entire house, which might reduce the cost per square meter. Ultimately, you should be prepared for prices ranging from 30 to even 40 € per square meter for labor.
Heating mats come in various types, with different prices and quality. The material cost ranges from 30 to 80 € per square meter. The labor cost can be similar to that of water-based heating, although theoretically, it involves less work (in practice, this can vary).
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