Warmboard For Builders

Warmboard Radiant Floor Heating For Contractors & Home Builders

What Builders need to know when working with Warmboard-S or Warmboard-R (and what you don’t need to know)

Warmboard S Installation

Warmboard – Perfect for new buildings, retrofits and heating upgrades, Installs directly on joist or existing floors.

As a contractor or home builder, you take pride in delivering quality craftsmanship to your clients. With Warmboard radiant floor heating, contractors feel good about providing clients with a heating system equal to the quality of your work. When that first cold snap hits, you’ll sleep peacefully knowing that this radiant floor heating for new construction and remodels consistently delivers greater comfort even under the most extreme conditions. It is the perfect system for those discriminating clients who would rather not wait to be comfortable.

Tubing spacing and conductivity are directly related. Radiant panels with low conductivity require more closely spaced tubing to produce adequate heat and reduce variations in surface temperature. Of course, closely spaced tubing increases tubing, manifold and labor costs and make the whole system more complicated to design. Warmboard’s ultra-high conductivity means that 300mm on center spacing delivers more heat, and spreads it more evenly than 6” spacing found in staple-up or thin slab systems. This even heat also means more flooring options for your client – from thick wool carpets to ornate hardwoods.

Warmboard radiant panels are also an ideal heating solution for structures featuring cathedral or open beamed ceilings. Forced air will not be able to provide the same level of comfort or efficiency for such spaces.

Furthermore, Warmboard requires lower water temperatures which mean more energy efficient heating. This is ideal for maximizing the efficiency of condensing boilers, as well as interfacing with solar or geothermal heat sources which are limited in their heating ability.

Warmboard-S, 28mm thick AS approved structural panel and part of the conventional framing process. Warmboard-S consists of 4 modular, tongue-and-groove panel types and weighs only 16kg. Warmboard-S is rated to carry all of the point loads, uniform loads and horizontal shear loads typically carried by 20mm sub-floor. It is ideal for 400mm or 60mm on center joists. Warmboard-S is a particularly stiff and strong sub-floor which delivers a sturdier floor for your clients.

Warmboard-R is also an ideal solution for new homes, and is often installed over slab foundations, subfloors or in the walls or ceilings. Warmboard-R is 20mm thick and made of the highest quality OSB. There are 2 panel types to accommodate your design. But primarily, Warmboard-R is used in remodels. The smaller panel size and smaller height makes layouts easy and customizable without affecting framing or existing door heights.

High mass systems, like concrete or gypsum concrete, are slow to respond and difficult to control, even with elaborate controls. Warmboard, due to its high conductivity and low mass simply responds quickly, providing the underfloor heating a contractor wants to offer clients. Uncomplicated control systems are easy to design, easy to install, save money and are highly reliable. Additionally, high mass pours that are not adequately dried can lead to potential mold issues down the road.

One of Warmboard’s greatest advantages is its compatibility with virtually all floor coverings. When you want to be the kind of radiant heat contractor that delivers the most versatile, effective option, Warmboard is the solution. Our panels work particularly well with hardwoods, making hardwood installations considerably easier and less expensive. Warmboard, delivers ample radiant heat through even the plushest carpeting, and tile or stone can be set over using conventional methods. Warmboard is the one radiant panel that doesn’t ask you to compromise your floor covering choices.

Follow These Easy Steps to Include Warmboard into the Design Process

1. When determined that Warmboard-S or Warmboard-R is appropriate for your project, please call Warmboard Australia 1300 137 407 or via our Warmboard contact form. You will be connected with one of our Warmboard experts If the structural plans are not yet complete, optimize the floor framing plan to most efficiently integrate Warmboard. Once completed, preliminary plans are sent to us, preferably in an AutoCAD format.

2. The consultant will discuss with you regarding zoning preferences, floor covering selections and other data necessary for proper design.

3. The Warmboard Design Team will produce a preliminary design for review and markup. These documents will include panel and tubing layouts, manifold locations and various detail drawings and notes. These documents should be thoroughly reviewed to ensure that they meet your client’s needs.

4. Our Design Team will provide a final set of documents, including corrections based on your markup for inclusion into your full set of construction documents. These documents are typically 1-25 scale plans formatted for A1-sized sheets, though other formats can be delivered upon request. We can also supply plans in the AutoCAD file format, or plot them on bond paper or vellum per your request.

Warmboard Gallery

Warmboard panel layout plans are easy to follow, panels are colour coded to match the panels shown on the layout. Layout shows starting point, cuts and instructions. 

Light weight flooring construction

Warmboard S requires joist spacing of 406mm centres (refer to our joist layout plan) for traditional joist application, fasten with panel withadhesive and 70mm screws, ring shank nails or 10D common nails. Apply common sense when sizing fasteners for TJI’s or Truss systems. When sizing a nail or a screw for a TJI or Truss system size the fastener to grab as much flange as possible, do not size nails or screws that will penetrate the bottom side of the flange, always refer to architectural specifications on the nailing pattern. recommends a 300mm inside, 150mm edges pattern as sheets are placed, alignment pins are tapped into place on the two outers most channels across the seam between the adjacent panels, to ensure proper channel alignment (see photo). Pay close attention to the panel layout plan as the work proceeds. All Warmboard panels, should be gapped 3mm at the butting ends.

Warmboard For Builders

Warmboard S exposure to weather*

Warmboard S panels are rated Exposure 1. Technically, they can be exposed to the elements for 1 year and still serve as structural subfloor. That said, Warmboard–S panels will still respond to moisture like any plywood product. This means swelling. Whenever possible, it is advantageous to avoid exposing the panels to rain. If Warmboard panels are exposed to weather, since they are protected on the top side by the aluminium skin, a common reaction is “edge swelling.” This means the edges swell up with moisture creating an uneven surface the panels will return close to their original shape when the moisture leaves the panels. If the panels have already been installed, one way to speed up this process is to install the tubing and get the system running. The heat will speed up the evaporation process. If the panels are installed over a crawl space, it is essential that the crawl space is completely dry and well ventilated. If the panels are installed over a slab, the slab must be completely dry with no water intrusion.

*Warmboard S Not be exposed to water when underfloor insulation has been pre-installed

Warmboard R exposure to weather

Warmboard R. Not to be exposed to water, must be kept dry at all times, warranty voided if not.

Ceramic Tile installation

Tile underlay 6mm board to be laid over the top of Warmboard in all tiled areas, underlay is supplied by builder or others and laid by builder or tiler, tile board is laid in the opposite direction to the Warmboard PEX lines.
(Tile underlay can be buttered on the underside with thin set before laying) then screw to the warm taking care to miss the Pex pipe installed, marking the board to show the installed Pex pipe is advisable, if a screw penetrates the Pex pipe advise the Hydronic heating plumber immediately. 

Alternative options for tile installation is available contact Warmboard to discuss.

Warmboard For Builders

Timbers Floors Over Warmboard Hydronic Heating

Timber flooring can be laid directly over Warmboard (Timber boards are laid in the opposite direction to the Warmboard PEX lines in most cases, however we need to know the direction of the timber flooring before the Warmboard panel layout designed.

Click here for more information 

Wet areas

All wet areas to have waterproof membranes installed as per standard building practise.

Underfloor Insulation

Warmboard S Thermal rating increases if insulated between the joists.

Warmboard S

Warmboard S is designed as a sub flooring to be built on, during the initial Warmboard design process. We use the Architects CAD drawing to lay the panels in such a way to avoid the PEX pipe going under the wall frame bottom plates, in cases where obstacles cannot be avoided, new PEX lines are routed into the board around the obstacle.

Warmboard delivery to site

Warmboard to be stored on a flat surface.

Warmboard S and WH&S

If Warmboard is exposed to wet weather during the build Warmboard can become slippery. We recommend thin ply sheets supplied by others be laid in traffic areas.

Warmboard installation

Warmboard is not difficult to install if the supplied directions are followed. First time installers should allow extra time. Most builders tell us it takes about approximately 10% more time over constructor flooring.


Warmboard S when installed across joists must be in the in the opposite direction to joist as per Warmboard S layout plan and other reference material supplied.

*Warmboard S installed incorrectly, Warmboard Australia accepts no responsibility for the outcomes.

Plaster and other material*

*Warmboard Floor protection film

Warmboard can supply a suitable surface protection film for the Warmboard surface after installation to assist keeping the Warmboard surface clean during construction, optional extra cost.

Warmboard For Builders
Warmboard For Builders