Snow Melt - Asphalt - EPS Foam

ChrisThomas · April 1

I have a client requesting snow melt for an asphalt driveway. I wanted to use Ampex or Crete Heat Panels with a layer of stone dust to protect the tubing and run cold water through while paving. I'm being told that I can't use foam because the petroleum will leach out of the asphalt and eat the foam. Also, the asphalt paver is asking if he can safely drive over the stone dust without damaging the pex. Is there an engineered spec sheet that shows this application? Any advice would be helpful.

Jamie Hall · April 1

The asphalt will degrade the foam. How much and how fast… I don't know of studies which have been done to check that. I think you're on your own.

As to loading on the PEX in the stone dust. No simple answer. It depends on three things: what is the load the asphalt guy is thinking about, how deep is the PEX buried in the stone dust, and how well is the PEX bedded in the stone dust and how well is the stone dust compacted. That said, even for ordinary traffic — heavy pickups and the like — I'd want to see the subbase graded and compacted at least a foot deep, to around 90% maximum density, then a bed of stone dust also compacted, then the PEX with the stone dust hand compacted around it, then at least six inches of dust, compacted, on top.

Jamie Hall · April 1

And a PS — what is the surrounding soil like? If it's silty or clayey, you're going to want that subbase to be a good foot of good material, and you'll want structural fabric between it and the native soil.

Derheatmeister · April 1

Snow Melt - Asphalt - EPS Foam

ChrisThomas

Apr 1, 2025

I have a client requesting snow melt for an asphalt driveway. I wanted to use Ampex or Crete Heat Panels with a layer of stone dust to protect the tubing and run cold water through while paving. I'm being told that I can't use foam because the petroleum will leach out of the asphalt and eat the foam. Also, the asphalt paver is asking if he can safely drive over the stone dust without damaging the pex. Is there an engineered spec sheet that shows this application? Any advice would be helpful.

How many Sqft is the proposed Driveway ?

GroundUp · April 1

We've come across this several times and had mixed results. What I've come to make my standard that works every time (and better, at a similar cost) is to set the base up just like a radiant slab. Embed the tubing in a 2-3" concrete pour, and then pave over the concrete. It lasts forever, and there is no possibility of shifting or crushing the tubing nor can the asphalt reach the foam. Heat transfer is far superior to stone dust and damage risk is nearly obsolete.

Derheatmeister · April 1

https://forum.heatinghelp.com/discussion/comment/1850647#Comment_1850647

One can just add Black color to the Concrete…

IMO this will have a better heat transfer and is Less labor intensive than a concrete pour then a asphalt on top of it. 😐️

Black will also help absorb passive energy (Solar/Sun) which will aid with the snow melting process. 🌞

GroundUp · April 1

https://forum.heatinghelp.com/discussion/comment/1850651#Comment_1850651

100% agreed, but for whatever reason nobody wants concrete. They want asphalt, and they're always right ;-)

ChrisThomas · April 3

Driveway is about 4,600 square feet.

hot_rod · April 5

I've found over the years in multiple homes in mountain climates that the asphalt hold up better than concrete. All concrete cracks, the control joints limit the traveling of cracks. Only a rebar grid keeps concrete from shifting at deep cracks. 6X6 mesh is not a substitute for rebar held into the pour.

It is really the sub grade below the concrete or asphalt that is the key. It needs to be compacted base material if you want a solid sub-grade.

Drainage is also important. Water in or under the drive going through freeze thaw cycles will cause problems, think pot holes :)

The PPI details various methods. The paving contractor needs to be onboard with the proper precautions. That is true with concrete or asphalt.

https://www.plasticpipe.org/common/Uploaded%20files/1-PPI/Divisions/Building%20and%20Construction/Division%20Publications/Presentations/Snow%20and%20Ice%20Melting%20System%20Solutions/BCD-presentation-sim-solutions.pdf