Installation Manual

4
4.3 Installation under Asphalt
1. Ensure that the paving contractor has a solid base of 4” to 8” (102 mm to 203
mm) of crushed rock aggregate tamped down and ready to receive the asphalt.
2. It is extremely important that the paving installer does NOT use any heavy
equipment, machinery, or vehicles over the exposed Heating Cable. Any tracked
mechanical spreaders or dump trucks must be prohibited from running over
exposed Heating Cable.
3. During this process of laying asphalt, installing the heating product, and
laying more asphalt, it is the responsibility of the electrician to use a 500 VDC
megohmmeter and a multi-meter to continuously check the Heating Cables that
are being worked on top of, to ensure they have not been damaged.
4a. The paving installer should lay down the binder / base coat of asphalt and roller it
smooth. The paving installer must decide if this binder coat of asphalt is allowed
to cool before nishing with the top coat of asphalt. This should be coordinated
with the installer of the Heating Cable or Mats. When working on top of hot
asphalt, please consider pre-making “wire mesh heating Mats”. This means
rolling out the reinforcing wire mesh (provided by electrician) and pre-attaching
the Heating Cable to it using wire ties (like rebar wire ties) that will not melt from
the hot asphalt. These “wire mesh heating Mats” could be left in the yard next
to the driveway while the rst binder coat is poured. While the asphalt is still hot,
two people could carry / drag each “wire mesh heating mat” over the hot asphalt,
have it ipped over so that it is wire-side-down / mesh-side-up, and then staked
down to the hot binder coat (stakes provided by electrician).
4b. If the paving installer decides to let the binder / base coat of asphalt cool prior
to nishing with the top coat, then wire mesh is only needed for free-form type
Heating Cable installations. WarmlyYours Snow Melting Mats may be staked
down to the binder coat without using any wire mesh (stakes may only pierce the
black plastic mesh, and should never make direct contact with the Heating Cable
itself). Again, it’s recommended that the Snow Melting Mat be laid down so it
is wire-side-down / mesh-side-up, to help protect it from damage by shovels.
When installing free-form type Heating Cable, stake wire mesh down to the
binder / base coat rst, and then attach the Heating Cable to it using wire ties.
This means it is wire-side-up / mesh-side-down, so extra care must be taken by
the paving installer to avoid damaging the Heating Cables with shovels or rakes
used to spread the top coat of asphalt.
4c. When the binder coat is in place, it is sometimes easier (especially when installing
tire track coverage) to have one person hold the roll of heating mat (wire side
down) as hot asphalt is shoveled over it. as the area is covered the installer
slowly unrolls the product until the remaining area is completed.
5. Once the heater cables are in place, the electrician must route the cold lead(s),
(20’ (6.1m) for 120V/240V or 50’ (15.2m) for 208V and 277V provided per each
Mat/Cable) through rigid metal conduit(s) or other approved means, to get back
to an accessible weatherproof junction box(s). The electrician may supply
junction boxes which can be accessed from above, so the rest of the box is
buried to avoid damage by lawn mowers and/or vehicles. Care must be taken by
the electrician so that none of the heated section of Cable enters the conduit(s).
If a slab-mounted snow sensor will be used, this is the best time for placement.
It should be located in an open area, away from trees or bushes, so that snow
will easily fall directly on it. Separate conduit should be used to protect the low
voltage sensor wire and must NOT be shared with any high voltage cold lead from
the Heating Cables / Mats.
6. Once the Heating Cables and conduits are in place, and are attached by the
methods listed, above the nal top coat of asphalt may be poured. At least 2”
(51mm) of material must cover the Heating Cable. The paving installer will be
required to spread this around evenly with shovels and rakes. Shovels should be
duct taped so the blade ends are less sharp. Again, the topping coat should be
spread manually to avoid use of heavy machinery. The only time it is acceptable
to use a mechanical asphalt spreader would be when it can straddle tire track
coverage used for longer sloped driveways. Tire track coverage allows the
spreader machine to be used without it ever making any direct contact with the
Heating Cables.
7. Once the top coat of asphalt is spread over the Heating Cables evenly with at least
2” (51 mm) thick coverage, it may be rolled over with the steam roller to nish /
atten the driveway. Again, each Heating Cable / Mat must be tested with a multi-
meter and 500 VDC megohmmeter to verify that they have not been damaged,
and to ensure they will be ready for activation (nal test) after the asphalt has
cured. These values should be recorded on the warranty card on page 35.