Underfloor central heating: the installation process during a new build

When it comes to the average home in New Zealand, a heat pump is typically the most common heat source you’ll see. But if you’ve ever experienced the warmth and cosiness of underfloor heating, it’s difficult to get past. 

When designing their new dwelling, a client of plumbing experts Lufdon Plumbing requested central underfloor heating, which is an unusual brief, says Lufdon Plumbing Director Lucas Findon.

“When Chris Gardner of Gardo Group approached us to carry out the plumbing work for a new build, we were happy to be on board, particularly given the job was an unusual one, with central heating integrated into the underfloor heating,” says Findon, “But our team is amazing – they jump at the opportunity to learn new skills and work on something a little bit outside of the square.”

The brief wasn’t just restricted to underfloor heating, though. It was the full scope of plumbing and drainage works for a new dwelling that includes two bathrooms, a powder room, kitchen, laundry and hot water system. 

The drainage scope included the installation of a pressure sewer system and stormwater retention tanks for rain harvesting, and a UV water filtration & pump install (supplied by Puretec). 

Of course, in addition to these standard plumbing and drainage works, Lufdon Plumbing was required to supply and install underfloor heating throughout the entire house (which is a Vario Comp underfloor heating system supplied by Central Heating NZ)

Here, we ask Findon about the process and timelines of installing the system. 

ArchiPro: How does the underfloor heating system work?

Lucas Findon: Hot water is pumped through a network of pipes which are laid under the finished floor. The water is heated via an air-to-water heat pump system. This system also provides hot water to bathroom and  kitchen outlets. 

AP: How is the site prepared for installation?

LF: Once the interior of the house is Gibbed and plastered, we begin our install. This involves installing a vapour/moisture barrier covering over the new sub-floor. We then lay 18mm thick cement boards which have pre-manufactured grooves for clipping the pipe into. Once the boards are laid, we then lay our network of pipes throughout each room back to a manifold system. The pipe and cement boards are then covered with a layer of flooring screed. The floor is then ready for the finishing material (for example, timber flooring). We then install all necessary components to the heating system, test and commission. 

AP: How long does the installation usually take?

LF: We estimate the installation from start to finish to take approximately two weeks but this is spread out over the various stages of the build.

AP: Were there any tricky issues? 

LF: Arranging the layout of the ‘engine’ room was a tricky one as there was limited space allocated, but all equipment needed to be installed in that space according to specs. We had lots of late nights researching in order to learn as much as we could about the system and the installation process! Central Heating NZ was fantastic to deal with – ordering the system and all the gear needed to install it was such a positive experience – they are really responsive, and knowledgeable about the products they sell, too. We were also lucky to have a great team of builders (Gardo Group, who we have worked with closely) to make sure the layout needs of the system align with the design needs of the build. We also worked in with the electricians who have an important role to play in a successful installation. 

AP: Does your team typically take on large, complex projects like this one?

LF: We enjoy taking on a range of different types of projects – it keeps us challenged and motivated.  Learning about new products, and nutting-out complex installations or working from complex briefs is right up our alley – even if it does cause a few grey hairs! We aim to offer a diverse range of services so that we can attract a wide variety of clients. Underfloor heating is a growing industry in New Zealand – it’s not been something that Kiwis (in the Bay of Plenty area anyway) have typically installed in their homes. 

AP: Have you got any exciting projects coming up?  

LF: We have a ‘sunken lounge’ job coming up, which we have been brought on especially to install the underfloor heating, so that will be an interesting one!

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