Exploded blueprint of a hydronic heated drivewayIsometric drawing of a heated driveway taken apart into its layers. From the bottom: native subgrade, a 150 mm Granular A base, 2 inch rigid insulation, reinforcing mesh, PEX tubing in a serpentine pattern with 6 to 12 inch spacing, a 150 mm concrete pour and the finished surface. Beside it: the manifold, a snow sensor on a post, a sensor set into the slab, and a boiler and controller in the mechanical room. Not to scale.1150 mm22 in346 to 12 in o.c.Mechanical room5610150 mm789SUNFLOW HEATED DRIVEWAYSHydronic driveway, typical section, explodedNot to scale. Dimensions are typical published figures.

Installation

How a heated driveway is put together.

Scroll or use the arrowsSwipe the drawing or tap the arrows to take a hydronic driveway apart, from the soil up, and see what each layer does.

  1. Part 1: Native subgrade

    The soil under the driveway, dug out to depth and compacted. Everything above depends on this ground staying put, so it has to be firm before any stone goes down.

    Typical compaction for soil: 96 to 98 percent.

    Source: Uponor snow and ice melting manual

  2. Part 2: Granular A base

    Dense graded aggregate, the material Ontario road specs call Granular A, spread and compacted. It gives the slab a solid, level bed so the heating system does not shift or settle.

    150 mm under a residential driveway in the City of Toronto standard.

    Source: City of Toronto T-310.050-8 and TS 1010 (OPSS.MUNI 1010); Uponor manual

  3. Part 3: Rigid insulation

    High density foam board rated to carry the weight above it, laid over the base where the design calls for it. It sends the heat up to the snow instead of down into the ground, and the system responds faster.

    Typical: 2 in (about 50 mm) board, about R-10, often run down the edges as well.

    Source: Uponor manual; SunFlow, Retrofitting vs. New Construction

  4. Part 4: Reinforcing mesh

    Welded wire mesh or rebar laid over the insulation. The tubing is tied to it, which holds each run at the right depth and stops it floating up while the concrete is poured.

    Ties about every 3 ft along straight runs, with extra ties at each bend.

    Source: Uponor manual

  5. Part 5: PEX tubing

    Oxygen barrier PEX tubing laid in a serpentine pattern. A warm mix of water and propylene glycol runs through it and heats the slab from the inside.

    Typical spacing 6 to 12 in (about 150 to 300 mm), up to 12 in for a home driveway. SunFlow sets the spacing from BTU calculations for the local climate.

    Source: Uponor manual; SunFlow, The Science of Snow Melting

  6. Part 6: Manifold

    Every loop starts and ends here. It shares the warm fluid between the loops so the far corner of the driveway gets the same heat as the end by the house.

    Before the pour, the loops are pressure tested, typically to at least 60 psi for 24 hours.

    Source: Uponor manual; SunFlow, The Science of Snow Melting

  7. Part 7: Concrete pour

    Concrete is poured over the mesh and tubing and sets around them. It holds heat well and radiates it up to the surface.

    At least 1.5 in (about 38 mm) of concrete over the tubing. A 150 mm slab for a residential driveway in the City of Toronto standard.

    Source: Uponor manual; City of Toronto T-310.050-8; SunFlow, Before Installing

  8. Part 8: Finished surface

    The part you see and drive on. Concrete is finished in place with planned expansion joints, while asphalt and pavers go on over a compacted sand bed.

    Sand bed over the tubing: typically 3 in under asphalt, 2 to 3 in under pavers. Shown here: brushed concrete.

    Source: Uponor manual; SunFlow, Before Installing and Finish Options

  9. Part 9: Snow sensors

    A sensor beside the driveway watches for falling moisture below freezing, and one set into the slab reads the surface temperature. The system runs only when both agree that snow is coming or already there.

    The slab sensor goes where the surface drains and warms like the rest of the driveway.

    Source: SunFlow, The Science of Snow Melting; Infloor snowmelt guide

  10. Part 10: Boiler and controller

    A dedicated high efficiency boiler in the mechanical room heats the water and glycol. The controller reads both sensors and decides when it runs.

    Fluid going to a concrete slab is kept at or below 150°F (about 65°C).

    Source: SunFlow, The Science of Snow Melting; Uponor manual

Put back together

It melts its own snow.

The controller holds the slab slightly above freezing. Snow that lands turns to water, and the warm surface dries.

Dimensions shown are typical published figures. SunFlow engineers the real ones for each property.

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The project

Four stages, one project manager.

  1. Consultation

    SunFlow starts by learning about the property, how you use it and what you want from it. Most consultations take less than 45 minutes, with no obligation.

  2. Design

    Your system is engineered for your property: grading, materials, drainage, landscape design and daily use. Tube spacing comes from BTU calculations for your local climate.

  3. Installation

    On a new build or full replacement, the tubing goes in before the surface is poured or laid. On an existing driveway, it goes into saw-cut grooves, or under lifted and reset pavers. Your project manager oversees every stage.

  4. Commissioning and handover

    Before winter, every component is tested, calibrated and adjusted, up to a final pressure test. You receive the documentation for your system.

The build, stage by stage

Base, insulation, tubing, then the surface: concrete, pavers or asphalt.

See the gallery
  • A driveway excavation filled with a compacted crushed-stone base, wooden form boards along the edges and a plate compactor on the gravel, in front of a brick house.

    Compacted gravel base with forms set

  • Light blue rigid foam insulation boards laid edge to edge over a compacted gravel driveway base, with wooden forms along the sides and spare boards stacked nearby.

    Foam insulation boards laid over the base

  • Red PEX heating tubing laid in even parallel loops with U-bends, tied to steel mesh over blue foam insulation across a whole driveway, with the tube ends gathered near the garage.

    PEX tubing on reinforcing mesh before the pour

  • Concrete flowing from a chute onto a driveway while two workers in high-visibility jackets, seen from behind, spread it over red heating tubing laid in loops on mesh.

    Concrete going down over the heating tubing

  • An interlock driveway part way through installation: finished grey pavers, a screeded sand bed, and red heating tubing still visible at the far end, with a worker setting pavers.

    Pavers going down over the sand bed and heating tubing

  • Two workers in high-visibility jackets, seen from behind, raking steaming fresh asphalt over a granular driveway base where heating tubing is still visible ahead of them.

    Hot asphalt spread over the heated base

Timing

Start early. The tubing goes in before the surface.

The best time to plan a heated driveway is while your home is being designed, or at least 3 months before you pave. That leaves time for utility planning and the boiler room setup.

  • Lead timeAsk SunFlow how far ahead installs are booking this season.
  • Install durationSunFlow gives you the days on site for your driveway with your quote.
  • WarrantyAsk SunFlow what is covered, for how long, and by whom.

Before you call

What helps SunFlow help you.

You do not need every detail settled to start. These make the first conversation more useful:

  • LocationThe property's town or address.
  • StageEarly concept, design, permits, under construction, or an existing home.
  • SizeApproximate dimensions of the area to heat.
  • SurfaceThe material you have or plan to use.
  • TimingWhen you expect the driveway work to happen.
  • DrawingsSite plans or drawings, if you have them.

Where the figures come from

The layer order and every dimension in the drawing come from these documents. Manufacturer figures are typical values; SunFlow engineers each system for its property.

Next step

Start with a conversation about your property.

Most consultations take less than 45 minutes and come with no obligation. Bring rough driveway measurements and the surface you have in mind, and SunFlow takes it from there.

Request a quoteEstimate your cost first