SLAB HYDRONIC
FLOOR HEATING

Q: How thick does a concrete slab need to be for underfloor heating?

The thickness of a slab is decided upon by your structural engineer but hydronic underfloor heating pipe must be covered by a minimum 30mm of concrete. Pipe can be attached to the top or the bottom side of the upper reenforcing steel.

Q: Can underfloor heating be installed in an existing concrete slab?

You cannot install hydronic underfloor heating within an existing slab but you can install it on top of an existing slab, within a minimum 50mm topping slab or sand and cement screed bed. Screed heating sits closer to the floor surface enabling a faster response time when turned on. Any type of floor covering can be installed on top of screed heating providing do you not penetrate the floor.

Slab hydronic underfloor heating is a highly efficient, radiant heating system and the ideal choice in open plan modern homes as an alternative to traditional and less efficient heating systems. Used for both residential and commercial properties, installed in new builds or retrofitting old buildings, providing a new slab is being poured.

Hydronic slab underfloor heating is ideal for large areas, 80m2+, where the slab is used as heat storage, creating thermal mass. The slab can heat during off peak times then slowly release the heat during peak periods, making in slab heating ideal when all day heating is required. Not ideal for holiday homes or small rooms as in slab heating can take 24-48 hours for the slab to heat up, depending on slab thickness and insulation.

Any type of floor covering can be installed on top of slab underfloor heating providing you do not penetrate the slab. Polished concrete floors are a popular floor finish to install with in slab underfloor heating as exposed concrete can be cold and hard underfoot.

Create thermal mass in the slab that radiates all day long

INSTALLATION

Hydronic underfloor heating pipe is attached to either mesh or reinforcing rods before the slab is poured. These pipes flow to one or multiple hydronic manifolds which are plumbed back to the heat source being a natural gas boiler or hydronic heat pump.

It is always advised to insulate under and around the slab to avoid heat loss and boost efficiency.

Comfort Heat must be advised of any expansion joints in the slab as pipes can pass over an expansion joint but with the correct installation method.

Slab hydronic heating requires 30mm coverage above the pipe to ensure the structural integrity of the finished slab. (this is therefore 50mm from the top reinforcing mesh to the finished surface of the slab)

PIPE TECHNOLOGY

REHAU PEX pipe is a cross-linked polyethylene pipe with an oxygen barrier to prevent corrosion and specially designed for underfloor heating systems. With in slab hydronic heating, we aim for a heat output of 100-120W/m².

TECHNICAL SUPPORT

Comfort Heat provides technical diagrams, electrical loads and helpful tele-support for a seamless installation. Your project manager will need to coordinate with a licenced electrician, plumber and concrete contractor to ensure all trades have the specifications they require.

CONSIDERATIONS

Pipe is covered by minimum 30mm of slab
Insulation recommended under and around the slab
Slow responsive heat

multi zone hydronic floor heating pipe and manifold in slab

multi zone hydronic floor heating pipe in slab

hydronic floor heating pipe in slab plumbed back to large manifold

hydronic floor heating pipe in slab and manifold

hydronic floor heating pipe in large house

hydronic floor heating pipe in Beach house

close up of hydronic floor heating pipe in slab

hydronic floor heating pipe in large slab

Brochures

Hydronic Slab Underfloor Heating

Hydronic Polished Concrete Underfloor Heating

TECHNICAL DATA

Pipe Type	Cross linked polyethylene pipe with oxygen barrier
Pipe Diameter	16mm
Slab Thickness	Minimum 30mm coverage above the pipe
Pipe Warranty	25 years
Cool Capacity	7kW ~ 23kW
Refrigerant	R32
Operating Range	-10ºC ~ +50ºC

FAQS

What Slab Hydronic Floor Heating Questions Customers Ask?

What is the best floor heating for a concrete slab?

Hydronic slab heating is the perfect solution for open plan homes and the most economical choice when looking at underfloor heating. Warm water circulates around, within the slab, creating a blanket of radiant heat and an unparalleled feeling of comfort.

The water in this closed loop circuit can be warmed by a hydronic heat pump, requiring only a quarter of the power of a gas boiler system and a sixth of the power of an electric system.

Heat Pump hydronic slab heating is the future of sustainable heating.

How thick does a concrete slab need to be for underfloor heating?

Is hydronic slab underfloor heating expensive to run?

Hydronic slab underfloor heating is the most economical of all underfloor heating systems.

Due to slabs having excellent thermal mass capabilities, slabs can be heated during off peak times and slowly release the heat over a long period of time.

Thermal mass is the ability of a material to absorb, store and release heat over time. Materials like concrete, bricks and tiles absorb and store heat well. They are said to have high thermal mass. Materials like timber and carpet do not absorb and store heat and are said to have low thermal mass.

Can underfloor heating be installed in an existing concrete slab?

MORE FAQS

Have Questions?

To find out more about underfloor heating, view our brochures or contact us to discuss all our products and services.

SLAB HYDRONIC
FLOOR HEATING