Expansion joints & underfloor heating

When the screed over an underfloor heating system dries, you can expect it to expand and contract with the changes in temperature. In order to protect the floor, and prevent it from cracking, expansion joints should be fitted during installation.

Expansion joints UFH

What are they?

An expansion joint can be easily made out of Nu-Heat’s edge insulation or any other flexible material, cutting holes around the tube position.

The purpose of an expansion joint is to allow movement to happen within the screed floor, releasing any stress build up to avoid cracking.

When should I use expansion joints?

For both liquid anhydrite and sand and cement screeds, expansion joints should be placed in high stress areas – these are where large areas are in contact with smaller ones e.g. in L or T shaped rooms. Expansion strips should also be used where UFH tube passes through doorways.

In sand and cement screed floors, expansion joints should be fitted when the surface area of the screed is great than 40m² or within any single length of screed greater than 8m.

What is expansion sleeving?

Expansion sleeving also prevents any stresses from building up in the tube to avoid damage. It should be placed around any piece of UFH tube that runs through an expansion joint (300mm either side).

Download our Screed Floors Information Sheet for more info.

Underfloor heating options for first floors

Did you know that it’s pretty simple to install warm water underfloor heating (UFH) on both ground and first floors?

Aside from the fact that UFH maximises available floor space and is a safer option for children’s bedrooms than radiators, installing UFH on both the ground and first floors will improve the overall efficiency of the heating system – particularly where a heat pump has been specified. You can also opt for a solution that offers acoustic benefits, reducing airborne and impact noise transmission.

Upper floors

What to look for

For a straightforward and quick installation, keeping costs down, it is important to choose the right system for the job.

Ideally, a good first floor UFH solution should be lightweight and offer:

  • No, or little height build-up, either being concealed in the floor deck or a low profile system that is laid on top of the deck
  • A flexible installation, giving you the option to either install from below after the floor deck has been laid, or over joists before the deck is down
  • A simple and safe installation

 

The 3 most popular first floor UFH systems

There are several first floor UFH systems to choose from on the market and these can be broken down into three main categories:

1. Metal heat transfer plates

Metal heat transfer plates, like Nu-Heat’s patented ClippaPlate® system, are placed over or between the floor joists to hold the UFH tube. Whilst there are a few different systems of this type on the market, they can vary considerably in the way they are installed and the quality of material.

Clippaplate over and between joists

A good system in this category will give you the choice of either working from above, before the floor deck is fitted, or below, before the ceiling is fitted – either way there should be absolutely no added height build-up. The benefit of installing the UFH from below once the upper floor deck has been laid is that it is quicker and safer and also enables other trades to continue with work upstairs – everybody wins.

It is important to choose a strong metal plate system that will hold the UFH tube flush against the floor deck – this helps to give an effective heat transfer. If the metal plates are too thin they could sag or bow over time, meaning that the UFH will have to heat an air void, which can impact the response times drastically.

2. Low profile pre-routed gypsum boards

LoPro®10 is an example of a retrofit UFH system that is also regularly specified in new build projects. This is a popular option when the floor joist structure can make installing UFH between joists impractical or the decision to include UFH is made later in the build schedule. This solution offers a good acoustic performance, helping to reduce airborne and impact noise transmission to the rooms below.

LoPro10 for upper floors

Most systems of this type are easy to install and are simply laid over the floor deck. The gypsum conducts heat well, giving an even heat output and quick response times. The overall height build up will be around 15mm and floor finishes can be fitted directly over the panels

3. Insulation and plates between joists

Another option uses pre-routed polystyrene panels that are installed between the floor joists before the deck is laid. Supported on a plywood base, the panels are installed flush with the top of the joists and incorporate heat diffuser plates to spread the heat evenly across the floor.

Although this method of UFH provides good heat output, the labour time to install the product can be prohibitive for new builds so tends to be best suited to retrofit installations where floor height build up is not possible.

Helping you to choose the right system

Thinking of installing UFH on a first floor? We are happy to talk you through the most suitable system for your project. You can speak to one of our UFH experts by calling 01404 549770.

10 reasons to sign up for underfloor heating training

UFH training

Nu-Heat’s UFH training days are useful for all types of installer, regardless of your level of experience, giving you the chance to take a closer look at key components and pick up some practical installation tips.

The course covers a lot of ground, but here are our top 10 reasons why you should attend our UFH course:

10 reasons to sign up for Nu-Heat’s underfloor heating training
  1. It’s a great opportunity for a hands-on look at all of the key UFH systems
    The training centre is kitted out with the most popular UFH systems, including Screed, Floating, the LoPro® range and ClippaPlate®.
  2. You can ask as many technical questions as you like!
    The course is run by James, our Design Manager, who has over 10 years’ of UFH experience. If you have any questions about how a system works, or how it is installed, he can help.
  3. Pick up tips for specifying the right UFH system
    We’ll talk you through specifying the right type of UFH system in the early stages of a project.
  4. Practise installing LoPro®10 and ClippaPlate®
    You can try out LoPro®10, a retrofit system, and ClippaPlate, a joisted floor solution, in our test installation bays.
  5. Find out about suitable floor coverings
    One of the most common questions we hear from homeowners is “what floor covering can I have if I go for UFH?” James will talk you through the range of compatible floor coverings and any considerations for more sensitive finishes.
  6. See how Nu-Heat’s design process helps you
    Find out how our detailed design process works and how the bespoke outputs, such as the detailed mechanical and electrical drawings, help with a smooth installation.
  7. See working examples of the products
    The training centre includes working examples of key system components to show how a UFH works, as well as a finished LoPro®Max installation.
  8. Find out more about control options and thermostat choices
    Nu-Heat offers a range of thermostat choices. We’ll talk you through the most suitable thermostats for different projects and explain how the neoStats can be simply upgraded to include smart control from a smartphone or tablet.
  9. Learn about wiring an UFH system with the help of a qualified electrician
    An hour of the day is spent with Peter, a Development Support Engineer and qualified electrician, so you can get an understanding of how an UFH system should be wired.
  10. Meet your Account Manager!
    Your Account Manager will always try to pop into the training day to meet you, putting a face to the name.
2016 course feedback:

How to book

You can find out more about the course content and book a place through the Nu-Heat Webstore or by calling us on 01404 549770.