Hi gang,
I have a client who’s masonry front steps ice up badly in winter. We are currently re-building them with bluestone treads. Does anyone know of a brand of electric radiant mats that we could place under them for de-icing purposes. I can find lots of indoor electric radiant mats, even electric mats for roofs, but nothing specifically for this sort of use. I can also find hydronic systems for the use but that would be difficult to install as he doesn’t have a boiler and getting the tubing from a boiler to the steps would be extremely difficult.
Thanks for the Input,
Tank55
Replies
The first thing I would try to do is find out why the steps are icing up. And fix that problem. Is it poor drainage, bad gutter/leader?
Tank we had some electric mats installed under stone stairs at my folks house. I can't for the life of me remember the name I look it up and get back to ya. Tim
I've done outrageous things with those roof heating strips. They look like a skinny 120-volt extension cord. They're intended to reduce ice dams on badly done roofs and result in those melted zig-zag patterns you see over the eaves of some low-pitch, poorly-built houses and trailers.
Anyway, they're designed to be out in the elements, year-round for a decade or more. Wind, ice, snow, water, high heat on a roof in summer, very high UV expsoure.
So I've shoved them down wells (to heat up a toxic waste site), buried them in the garden to thaw the ground a little earlier, and abused the heck out of them with no problems.
They are something like 500 to 1000 watts each (varies with length). I'd figure the watt density you want (more is better because it will melt the ice faster and spend less time heating the great outdoors). And buy as many as equals that wattage. Bed it in the concrete step itself, near the surface. Or within a thick layer of thinset if you're doing tile on existing concrete. Never cross heat trace cables! Plan a pattern than does not double over itself.
Water-proof 120-volt plugs will project out of the steps. Give some thought as to how far away you'll join them together and run them to a outlet on a timer. Ideally, the GFCI and timer would be inside so 1) they last longer and 2) you don't have to go outside to thaw the steps. But there are a lot of outdoor-rated timer and remote control switches for Xmas lights. Look for a high-wattage one.
Note that with any ice-melt scheme, you REALLY want a slight slope to drain the melt water. It only takes 144 BTU per pound to melt ice. It takes another 1000 BTU per pound to evaporate the melt water. (That's 0.042 kWh / pound of ice or 24 pounds of ice melted per 1.0 kWh if you're figuring electrical needs). Figure about 30% efficiency going from electrons to melt water. You've got to heat the concrete and you won't avoid heating the air somewhat.
If you sweep the steps first, it will snow melt a lot faster (duh!). With thick snow, you get bridging over the cable locations and it takes longer than when the snow is all in good contact with the slab.
David, nevr thought of using roof cables. Good idea. However if your gonna install bluestone treads, hide all of the electrical. It's worth the effort. Put the control on a quality thermal switch so as to run only when needed. Never spent a winter in Kenai, did however spend a few summers in Nikishka. Tim
Try http://www.tycothermal.com/usa/english/snow_melting/ They make electric heat tracing products for sidewalks and driveways, roofs and gutters, pipes, etc.
Stuart, and everyone else who posted back to me on my question. Thanks, it is a big! help.
Tom