6 min read
How much underfloor heating do I need and how much does it cost?
Probably if you’ve ended up at this blog, you’ve already decided to use electric underfloor heating in your project.
Well, that’s a good question I must admit! The short answer is ‘not much’ but that doesn’t really cut the mustard for most people, so I have done my best to prove it.
People often ask us how much electric underfloor heating costs and it’s a very valid question because everyone has a budget and they do their best to stay within that budget, mostly. The fact is the full set up can cost as little as £330 for a 4sqm bathroom.
That’s right. Only three hundred and thirty pounds!
So, for the purpose of this blog, we’ll be using a 4sqm bathroom as the example when we discuss costs.
Alright, now I have your interest, lets dig into the detail.
Typically, the cost depends on what floor build up you are going to have. The most common floor build-up is the following (excluding and flexible tile adhesive):
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Other floor build-ups consist of:
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Or
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Let’s look at individual prices for each layer of the most common build up, based on a 4sqm bathroom.
Insulation board is key to make the system as efficient as possible by preventing heat being lost through the substrate. Without insulation board, the electric underfloor heating system will cost more to run because it will take longer to reach the target temperature. So, we better include that in the price.
For concrete substrates you use uncoated insulation boards and for timber substrates you use coated insulation boards. These typically cost between £14 and £24 per sqm. So, in this example, it’s going to cost between £60 and £100 (adding a bit for wastage). For further detail on why insulation is vital, read our blog ‘Why removing insulation board is costing homeowners.’
OK that was easy! Let’s look at the heating itself.
You can get different outputs of heating mats, some companies sell 160W/m2 as standard, some sell 150W/m2 as standard, some even range between 100W/m2 and 200W/m2. The higher the wattage the faster the time to heat up. Higher wattages are typically used in rooms that have a higher heat loss such as conservatories.
The pricing doesn’t change a huge amount between the outputs so typically, when buying a premium grade heating mat for a 4sqm bathroom, it should cost anywhere between £155 and £210. You can read about the 5 top electric underfloor heating brands here to decide what’s right for you.
Oh, and don’t forget the thermostat! (Your heating won’t do much without it). There’re lots of different types of thermostats available but the most important thing is to choose one that most suits your lifestyle. Our article ‘What is the best thermostat to use for underfloor heating?’ provides some top tips for selecting the right thermostat A standard programmable thermostat that will fit in with the majority of projects will cost anywhere between £75 and £140.
So, after all that, the total costs for underfloor heating in this kind of build-up is between £330 and £450
Is everything making sense so far? Good, let’s look at some more complex build-ups!
The build-up gets a bit more complex if you are installing heating under wood, carpet or vinyl. I mean, when I say complex, there’s just a few extra things to consider. Here’s an example of a build-up under carpet.
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Insulation
So, as you may have noticed there is a few extra layers in here. Let’s start with the insulation. The insulation is the same whatever is going on top however, you do have to use a different type of insulation depending on what the substrate is. As before, this is going to cost between £60 and £100 for a 4 sqm room.
Underlay, Heating, Overlay
The next part is the underlay. Now, the underlay and overlay are there to protect the heating itself, so I am going to talk about the 3 layers together. Some companies sell them separately, some sell it as kits, some give you the option of both. But it’s important that all 3 layers are present and here’s why.
The Foil system like Warmup’s Foil Heater, Heat Mat’s Combymat System and our own ThermoSphere Foil are all systems that require no wet trades. This system is the industry standard for wood, carpet and vinyl floor finishes for that reason. This does mean that you need to protect the heating cable as its not embedded in an adhesive layer and is exposed to compression within the floor itself. The cushioning layer underneath the foil gives the heating system sufficient protection so there is a significantly reduced risk of the heating cable getting damaged during installation.
This foil distributes the heat (does the job of the tile adhesive in a mesh installation) so that the cable doesn’t overheat.
The overlay is a vapour barrier. This is usually a requirement whether there is heating or not, but some companies like to include a cushion backed vapour barrier for heating installations to give added protection to the heating cables.
As these three parts go together, I thought it would be easier to give a total price for the whole package rather than individual parts. So here goes – between £245 and £280 for a 4 sqm area.
Addition layers for soft floor finishes
If you’re having a soft floor finish such as carpet or stick down vinyl, then you will need an additional structural layer such as HDF or cement overlay board to provide a firm surface to fix to. These can cost anywhere between £160 and £300 for a 4 sqm room.
Overall, heating systems for wood carpet and vinyl can cost anywhere between £420 and £800 depending on what your floor finish is.
There are other systems on the market such as a decoupling membrane system which is great for tiling over as it prevents the tiles from cracking when there is expansion in the substrate. It is also perfect to use in wet rooms as it can be used as a waterproofing layer. This system would be exactly the same build-up as the mesh system (used in first example) but instead of the mesh you would use this membrane heating layer instead.
Before I get onto the cost, many tilers would install a decoupling layer regardless of what system they use so by incorporating the decoupling membrane into the heating system, you are saving money and time as there is only one layer to put in, instead of 2 or 3.
This membrane system can cost anywhere between £40 and £60 per sqm. So, with the full build up in mind, a 4sqm room would cost between £350 and £470 (including flexible tile adhesive to stick the membrane down). Also bear in mind that the tiler won’t have to purchase an additional decoupling mat as part of the overall cost.
Let’s go over the labour costs. This is important to consider as it can be quite a big chunk of the overall expense for the project. Anyone can install our products, from general builders, to electricians, to tilers, to plumbers. As long as an electrician provides the fused spur, the rest of the installation can be done by a competent person and the installation can be signed off and the warranty registration completed.
A 4sqm bathroom would take 1-2 days depending on what type of system you went for. Labour costs can range from £120-£180 depending on what trade you go for.
All in all, it can be quite a daunting task to price up jobs but hopefully I have given you a bit of insight into what is needed for the different floor build-ups which will give you a better understanding of how much electric underfloor heating costs overall.
The short answer when someone asks how much does underfloor heating cost for my 4sqm bathroom? it’s between £450 and £800.
If you do have any further questions regarding the cost of an electric underfloor heating system, then our team are on hand to help. Simply contact us for further support.
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