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Underfloor Heating Installation: How-to Lay Wet UFH Yourself

installing underfloor heating
(Image credit: c/o Wunda Group)

Underfloor heating installation might not be your first thought for something you can DIY during your build to save money; however, there's some scope to take on  elements of this job yourself if you've got the required skills. 

However, bear in mind that there are certain elements on installing underfloor heating are notifiable, and when installing a new underfloor heating manifold for a wet system, this will need to be done by an appropriate qualified professional. 

Whether you're considering underfloor heating installation on a DIY basis or just want to understand what the process involves, here sustainable building expert Tim Pullen lays out the process step-by-step. 

Of course, it's important to remember that you should only take on DIY projects that are within your capabilities. Get something wrong, and rectifying your mistakes is likely to cost you more than the potential savings you'd hoped to gain. 

How to Install Underfloor Heating 

installing underfloor heating

(Image credit: c/o Wunda Group)

1. Connect the pipe to the manifold 

The first step is to connect the floor heating pipe to the underfloor heating manifolds. The manifold will have already been installed by a professional and you shouldn't undertake this on a DIY basis. 

installing underfloor heating

(Image credit: c/o Wunda Group)

2. Lay underfloor heating insulation

After laying your insulation, you will need to begin to lay the pipe. This is an important element, and shouldn't be overlooked — laying insulation under underfloor heating will improve the efficiency by resisting the heat from going downwards 

3. Begin to lay the pipe

After laying your insulation, you will need to begin to lay the pipe. Make sure to clear the subfloor before laying out the pipes to ensure there's nothing that will damaged the pipes. 

installing underfloor heating

(Image credit: c/o Wunda Group)

installing underfloor heating

(Image credit: c/o Wunda Group)

4. Fix the underfloor heating pipes 

Secure the pipe to the insulation as you go using pipe staples. Ensure you fix the pipe with the correct spacing to ensure optimal heat distribution.

installing underfloor heating

(Image credit: c/o Wunda Group)

5. Install across the whole floor 

Loop the pipe across the whole floor area, using multiple loops for large spaces.

installing underfloor heating

(Image credit: c/o Wunda Group)

6. Prepare the screed 

Mix the screed or opt for a ready-mixed version. The pipes must always be pressure tested before the floor screed is laid. Equally important is to ensure the pipes are full of water while the screed is being laid so that if there is any damage it will be immediately obvious and can fixed before the screed laying is finished.

installing underfloor heating

(Image credit: c/o Wunda Group)

7. Pour the screed

Carefully pour the self-levelling screed over the pipework, ensuring that the pipes are securely fastened and the insulation is sitting flat. 

The screed is stabilise with a chemical spray, before being finally tamped for a smooth finish. 

installing underfloor heating

(Image credit: c/o Wunda Group)

8. Leave to dry

Leave the screed for at least 7 days to dry before turning on the underfloor heating. At this point, turn the underfloor heating at the lowest temperature, gradually increasing it over a number of days. 

installing underfloor heating

(Image credit: c/o Wunda Group)

Tim is an expert in sustainable building methods and energy efficiency in residential homes.