How do you find the heating cables before repairing a heated garage ramp?

To repair a heated parking garage ramp without cutting a cable, have the building energise every heating circuit, walk the ramp with a thermal camera, and spray-paint the cable runs onto the surface before any tool touches it. The heating element is cast into the ramp and invisible from above. It is expensive to repair, easy to hit, and on most ramps in Toronto there is nothing separating it from the surface being worked on.

Why can’t a heated ramp be repaired like any other ramp?

A heated garage ramp carries an electric heating cable buried inside it, which turns ordinary surface work into work with a live hazard underneath. On an unheated ramp, chipping out a failed patch or routing a crack risks nothing but the concrete. On a heated ramp the same tool at the same depth can sever a cable loop and take the ramp heating out of service in the middle of a Toronto winter.

The repair to that cable is not a patch. The cable sits inside the ramp, so reaching a break means opening the surface above it and putting the ramp out of commission for longer than the original repair would have taken.

How do you locate the heating cables in a garage ramp?

Heating cables in a garage ramp are located with a thermal camera while the heating is switched on, then marked in spray paint directly on the ramp surface. The sequence is the whole method:

1. The building energises every heating circuit. Not most of them. Every one.
2. The ramp is walked with a thermal camera. Warm cable reads clearly against cold concrete, and the loops show up as a legible pattern rather than a guess.
3. The runs are spray-painted onto the ramp, in place, so the marks sit in front of the crew for the whole job rather than on a drawing in somebody’s truck.
4. Only then does work start, laid out around the marked runs.

It is a cheap step. A camera pass and a can of paint against the cost of an opened ramp is not a close call.

What goes wrong when the heating isn’t fully turned on?

A heating cable that is switched off is invisible to a thermal camera, because it sits at exactly the same temperature as the concrete around it. That is not a limitation of the camera. There is nothing to see.

We have cut a cable this way. The building turned on part of the ramp heating, the survey read the energised sections and showed nothing over the rest, the unheated section was treated as clear, and the cable in it was nicked. Nothing about the camera work was wrong. The input was incomplete.

This is the one part of a heated ramp repair a property manager directly controls, and it is worth being blunt about. If the building cannot confirm that every circuit is live during the survey, the survey is not finished. Reschedule it rather than work around it.

Why does the ramp’s construction decide how much risk the repair carries?

How a heated ramp was originally built determines whether surface repairs go anywhere near the heating element. There are two arrangements and they are not equally forgiving.

The good design puts a structural ramp slab at the bottom, then a second slab laid over it carrying the heating element, and the wearing surface on top of that. Because the element lives in its own layer, the surface above can be stripped, recoated or replaced without going near a cable. Coating work is genuinely free and clear.

The common design puts the cable straight onto the structural slab and pours the wearing course — asphalt or mastic — directly over it. The heating element is now inside the layer that wears out, which is the layer that gets repaired. Every crack fill, every patch, every recoat is a cable risk.

The three wearing surfaces we see on ramps are mastic, asphalt and concrete. Mastic is by far the softest of the three, so a tool goes through it fastest and gives the least warning before it reaches whatever is below.

The consequence for a building with the second arrangement is simple: the marking step is not optional, and it does not get skipped because the repair is small.

What should a property manager do before the crew arrives?

Three things, all of them cheap:

• Confirm the ramp is heated at all, and find out which panel and contactor feed it. Plenty of buildings are unsure.
• Arrange for every heating circuit to be energised on the survey day, in any season. Summer work still needs the heat on.
• Find the original ramp construction records if they exist. Whether the element sits in its own topping slab or in the wearing course tells the contractor what kind of job this is before anyone quotes it.

Ramp work is normally staged rather than closed outright. On a garage ramp recoat at a mid-rise residential building on Esther Lorrie Dr in Etobicoke we recoated in two parts, working one side at a time so the ramp stayed usable throughout. The same staging applies on a heated ramp, with the cable mark-out done across the full width first.

Once the cables are marked, the next decision is what actually goes into the crack — and on a heated slab that choice is not the same as on an ordinary one. See why you shouldn’t caulk a crack in a heated concrete ramp. If water is collecting at the bottom of the ramp rather than on it, the source is often the trench drain.

If a leak elsewhere in the structure is what put the ramp on your list, the cause is often not the ramp surface at all — our article on why parking garage expansion joints leak covers the joints running through the same decks. Wider surface deterioration is covered on our parking garage waterproofing and concrete surface repair pages.

Before booking ramp work this year, find out whether your ramp is heated and where its panel is. If it is heated and nobody can tell you how it was built, put that question to the contractor before the quote rather than after the repair.