How To Install Underfloor Heating On Concrete Floor
Underfloor heating is a luxurious feature to add to your home but has become more affordable for many looking to provide additional warmth to the property.
There may be a number of reasons for installing underfloor heating, whether that be to cater to cold spots, save on space, or just for that toasty feeling underneath your toes.
Underfloor heating systems are very versatile and can be installed under nearly all types of flooring, from wood, laminate, stone, and even carpet. If you're looking to install underfloor heating on existing concrete floor surfaces, that's totally doable too.
In this guide, you'll understand the difference between electric underfloor heating and wet underfloor heating, as well as how to install underfloor heating on concrete floor surfaces, as well as any other floor types that it caters to.
You can check out our comparison guide between electric vs wet underfloor heating to help provide you with more information on the subject.
The Installation Process for Underfloor Heating On a Concrete Floor
We would always recommend you turn to the experts when it comes to installing underfloor heating, particularly when you don't have any skills or expertise. However, if you've done your fair share of DIY, it's a project that, once completed, can provide you with a great deal of satisfaction.
This step by step guide should be helpful when it comes to the installation process involved when fitting underfloor heating on concrete floors.
Firstly, you'll need to insulate the home with the use of insulation. The type you use will depend on your budget and what suits the space best, but this is critical to making the most out of your underfloor systems.
Make sure your walls, loft and floors are completely insulated so that the heat produced by the heated flooring isn't quickly escaping. When you're working with polished concrete flooring, it's necessary to insulate all areas of the home where heat can naturally dissipate.
Some traditional insulation options include rigid foam insulation, foam spray insulation and aluminium foil-backed insulation.
Installing polystyrene boards
Next up is installing the polystyrene boards. These boards provide ample insulation but it's important to consider how thick they are due to compromising the room's height if too thick.
It's important to note that you don't want to run any underfloor coils directly onto a concrete floor without at least laying down insulation; otherwise, the majority of the heat won't even reach the surface.
Installing the heating pipes
You'll then want to install the heating pipes which are fixed onto the top of the insulation boards. These coils need to be aligned close together in order to have a well-balanced amount of heat. You want to avoid any cold spots, so make sure to keep them close.
Placing a layer of screed over the pipework
Follow this up by placing a layer of screed over the pipework. This screed is typically made up of cement and sand, which is put over the pipework so that it protects the pipes from collapsing due to the various furniture or traffic in the room.
Applying floor finishes
There are plenty of different flooring finishes for underfloor heating, so depending on the budget you have and the finish you're after, you may wish to add tiles, wooden boards or even carpet to the floor construction.
Factors to Consider When Installing Concrete Over an Underfloor Heating System
When it comes to an underfloor heating system, there are some important factors to consider when installing it where concrete is concerned.
Account for extra thickness
The thickness of the concrete can influence how well the heating is distributed and how quickly the floor heats up. Make sure that the application of the concrete layer is between 50mm-75mm where possible.
A perimeter joint should be used around the floor area
Perimeter joints are helpful when it comes to keeping everything in place. It'll ensure nothing is compromised when it comes to fitting the insulation, the heating systems itself and the concrete poured on top.
Avoid the risk of concrete cracking
Concrete can crack fairly easily if the moisture doesn't evaporate slowly. This can be helped by keeping the room well ventilated and by spraying the concrete with water a couple of times every day in the first week you've poured it.
Consult with a concrete specialist
If you've got any concerns about laying down the concrete or installing the underfloor system itself, it's always good to seek the expertise of a concrete specialist. These individuals know concrete and can help advise you on the best way to ensure your concrete gets laid down perfectly.
Employ experienced heating engineers
If you're perfectly fine with everything but the heating installation itself, then it's a good idea to employ experienced heating engineers to do it all for you. The last thing you want is to do all of the work and then encounter faults that mean you'll need to rip up the new flooring. Retrofitting underfloor heating can be difficult, so don't be afraid to get help!
What Is the Right Type of Concrete for Underfloor Heating?
Possibly the most popular type of concrete for underfloor heating is semi-dry screed. This is one of the most traditional options to choose from and is made from a mix of cement and sand. It's usually a ratio of 3:1 or 4:1. Water is then added to help create a smooth consistency to the flooring.
From a technical point of view, concrete with a hardness of C35 or 35 newtons with a water to cement ratio of less than 0.40 will be the most appropriate.
Which Is the Best Underfloor Heating System for Concrete Floors?
What are the best heating systems when it comes to concrete? We'd recommend either electric or wet underfloor heating. Here's a brief overview of what each one is and how they work.
Electric underfloor heating system
An electric underfloor heating system consists of a thin heating wire that is installed under the floor's surface. The wires will warm up when desired and heat up the floor. This type of system is suitable for any renovation project where there's little disruption.
This type of system is great for those wanting slower heat-up and cool-down times, which is handy in rooms that are forever being used.
Wet underfloor heating system
Wet underfloor heating systems are perfect for those who want to install them with newly polished concrete floors. This is the ideal flooring material to cover this type of system.
A water-based heating system uses a series of pipes connected to a boiler and circulates warm water through the floor to heat up the space. It's more evenly distributed than standard radiators and is handy for heating pipes when it's underneath the concrete.
How Much Does Underfloor Heating Cost to Install?
Underfloor heating can vary depending on the system you choose and the labourers that are involved in the process. The amount of space to cover also needs to be factored in as well as any additional renovation work that's required in order to install it.
According to Checkatrade, the average underfloor heating installation costs anywhere between £500-£8,000. Electric systems are more affordable than wet systems, so it's worth considering what your options are and whether you need something budget-friendly.
It's a good idea to assess your criteria so that you can install underfloor heating successfully and not so much that it's going to break the bank!
If you're still unsure about the price associated with underfloor heating, find our guide which provides a breakdown of the underfloor heating costs in the UK.
Can you install underfloor heating on an existing concrete floor?
It is possible to install underfloor heating on an existing concrete surface or subfloor for that matter. If you've got a polished concrete floor already, then you'll likely be able to fit insulation along with a low-profile electric floor heater. This can then be covered up with a layer of levelling compound and polished concrete on top.
It's always a good idea to see what can be done before ripping up any flooring, and it costs more money as a result.
Does underfloor heating go on top of the screed?
The most practical way of applying underfloor heating is applying floating screeds. This is then placed on top of the underfloor heating. This helps in providing the best solution for insulating your home properly.
How much concrete do you put over underfloor heating?
When it comes to applying concrete to your underfloor heating, it's good to have a thickness of 50mm to 75mm. The additional thickness can help it cope better with the heating process, so the thicker it can be, the better.
Can you have polished concrete over underfloor heating?
Yes, applying a polished concrete floor over underfloor heating is possible. It's a great way of helping distribute the heat well as it has a higher thermal mass in comparison to other floor types.
Underfloor heating is a radiant floor heating solution that many households are becoming more aware of in its benefits and luxurious appeal.
If you're looking to elevate your home environment with underfloor heating pipes, make sure you follow the guide carefully. You should also be aware of the costs before you start this home DIY project.