When it comes to underfloor heating, many people focus on the thermostat temperature, but that’s only part of the story. It’s equally important to understand how different flooring materials react to heat and influence heat transfer, so you can manage expectations and ensure the best outcome.
Two rooms set to a floor temperature of 25°C can feel completely different under bare feet. The same goes if you’re controlling by room temperature rather than floor temperature. Why? Because the material, thickness, and installation method of your tile have a major influence on how heat flows, how quickly the floor warms up, and how it feels to the touch.
Let’s unpack this.
The Science Behind the Feeling
Warmth is not just about surface temperature or a number on a screen, it’s about how heat moves. When your foot touches the floor, what you perceive as “warm” depends on how quickly the surface releases heat into your skin.
This is influenced by:
Thermal conductivity – how fast the material transfers heat
Thermal mass – how much heat it can store
Tile thickness – thicker tiles take longer to heat
Surface texture – polished tiles feel warmer than porous ones
Installation method – screed vs. direct stick (see below)
Tile Types Compared
Here’s a comparison of some of the most common hard flooring surfaces used with underfloor heating:
Note: All of these materials work well with Warmset underfloor heating — but understanding their properties helps you make smarter design and comfort decisions.
Why Does a 1°C Difference Feel So Big?
Imagine this:
Room A has a 7 mm porcelain tile, reading 21°C
Room B has a 15 mm natural stone tile, reading 20°C
Despite being only one degree apart, Room A feels noticeably warmer underfoot. That’s because the thinner, more responsive porcelain tile transfers heat into your skin more quickly. In contrast, the thicker stone tile takes longer to release stored heat and can even draw warmth away from your foot at first contact.
Installation Method Matters Too
There are two common ways to install underfloor heating mats beneath tiles:
1. Under Screed
The heating mat is embedded in a layer of screed (concrete or sand/cement mix). The tiles are then glued on top of the screed using tile adhesive.
Slower to heat up, but stays warm longer thanks to higher thermal mass
Ideal for large areas with consistent heating patterns
2. Direct Stick (Under Tile Adhesive)
The heating mat is installed directly beneath the tile in the adhesive layer. A thin layer of self-levelling compound is often used first, making the tiler’s job easier and improving heat distribution.
Much faster to heat up (often 15–30 minutes quicker, depending on the size of the room)
More efficient for bathrooms, kitchens, and daily timed use
Delivers more immediate barefoot comfort
Warmset mats are fully compatible with both methods.
3. Real life scenario with stone tiles
In the picture above, we can see a 15mm stone tiles floor over 80sqm of space. This is the kitchen and living area, where owners David and Angela spend most of their time when home. The tiles were glued over an 8mm layer of self-leveling compound. The floor temperature was set at 25 degrees.
We installed Warmset Gold at 100W/sqm, with no underfloor insulation (unfortunately, being this a renovation, we did not have enough elevation).
So: thick tiles, slow heat up times, high conductivity but no insulation and an extra 10mm layer to get through – a pretty tough operating condition for anyone!
When the heating was turned on for the first time, the floor temperature was 16 degrees. Admittedly, it took a few hours for the floor to reach the set 25 degrees. Once there though, the room felt beautifully warm and very comfortable.
The thick layer of tiles would then continue to radiate gentle heat, with minimal intervention.
Design Tip: Thin Doesn’t Mean Cheap
Thin tiles like porcelain often outperform thicker, more luxurious materials like marble or stone when it comes to responsiveness and barefoot feel. You’re not compromising on quality, you’re choosing a smarter match for underfloor heating.
That said, if you’re in love with marble or stone, Warmset is absolutely suitable: we’ll tailor the system to deliver comfort, efficiency, and long-term reliability.
Let Us Help You Choose the Right System
At Warmset Australia, we go beyond product supply. We help you plan your heating system for optimal performance, energy savings, and comfort tailored to your floor type.
Whether you’re using porcelain, terrazzo, or natural stone, we can customise the heating wattage to ensure it performs beautifully with your selected material. (For projects over 100 sqm — otherwise standard stock wattage is 150W/m².)
Want advice for your specific project? We’re here to help.
