Of all the upgrades people add during a bathroom fit, underfloor heating gets the most consistent praise afterwards. It is also one of the few that must be decided before the floor goes down, because retrofitting it later means lifting everything again.
Electric mat, the usual choice in a refit
- Thin mat or loose cable set in levelling compound, then tiled over.
- Typical fitted cost £450 to £900 in a standard bathroom including the thermostat and the electrical work.
- Adds around a day to the programme, mostly waiting for the levelling compound.
- Works on timber and solid floors alike.
Water system, the choice during bigger works
- Pipe loops in screed, connected to the heating system through a manifold.
- Cheaper to run and gentler, but only sensible where floor levels are already being rebuilt.
- Best suited to extensions, ground floor renovations and knock through projects.
Sizing it properly
Heat the free floor area, not the room area. Nothing goes under the bath, the vanity, the toilet pan or the shower tray, so a 6 square metre bathroom might only take 3.5 square metres of mat. That is why an accurate layout has to come before the order.
Details that make or break it
- Insulation boards under the mat, otherwise a good portion of the heat goes into the floor structure.
- The floor probe placed between the loops and inside a conduit so it can be replaced.
- Resistance tested before and after tiling, so any damage is found while it is fixable.
- A flexible adhesive rated for heated floors.
- A programmable thermostat with adaptive start, so the floor is warm when you get up rather than an hour later.
Is it worth it?
In a room you use twice a day where the alternative is a cold porcelain floor, most people say yes. It also lets you fit a smaller towel rail and free up wall space, which in a small local bathroom can be the deciding factor.
Ask for it in your quote
We price underfloor heating as a clear line item so you can see the number and decide. Free survey, fixed price within 24 hours, all plumbing, tiling and electrics carried out in house by our own insured fitters with a written workmanship guarantee.
Common questions
Is electric underfloor heating expensive to run?
In a bathroom, no, because the area is small and it runs on a timer. A typical 4 square metre mat costs pennies per hour and is normally set to come on for an hour or two around morning and evening.
Do I still need a radiator or towel rail?
In most bathrooms yes. Underfloor heating on its own can struggle to meet the heat loss in an older uninsulated room, and you still want somewhere to warm towels.
How much height does it add?
An electric mat with a levelling compound adds around 8mm to 12mm. A water system in a screed adds considerably more, which is why it usually only makes sense in an extension or full renovation.
How long does the floor take to warm up?
Typically 20 to 40 minutes for an electric mat under porcelain. A programmable thermostat with an early start function handles that for you.
Can it go under any floor?
It works best under tile and stone. It can go under some vinyl and engineered products, but only where the manufacturer permits it and with the temperature limited.
Who does the electrical connection?
We do. Our own fitters handle the electrics alongside the plumbing and tiling, the circuit is tested and certified, and the thermostat is commissioned before we hand over.