YATES ON PLUMBING
By Dave Yates, Plumbing Contractor
©2005 All Rights Reserved
Many Heat Tapes Can Pose a Fire Hazard
My August
column about winterizing plumbing systems generated a number of e-mails.
Several questions were asked on using electric heat tapes.
A memory long
tucked away in the back recesses of my mind rose to the surface: It was a bitter
cold winter, and the worksite was an egg farm that housed a number of dilapidated
house trailers billed as a “Farm Vacation” for big-city dwellers. “Farm fresh eggs
you can gather right from the hens.”
I’d spent more
time in the henhouse than I ever wanted while repairing water lines on previous
visits, and I would bet that romantic notion of handpicking eggs was shattered
the second an unsuspecting vacationer stepped over that threshold. The overwhelming
ammonia from the decomposing chicken poop, deposited by several hundred thousand
birds cramped three-to-a-cage, was always an affront to the senses! There was also
a horde of flies to contend with during warm weather.
Every winter
during the worst weather, one or more of these mobile homes—a misnomer given their
absence of wheels—would have its skirting blown away or forgotten-to-be-repaired,
leaving a gap for old man winter’s frosty breath. Since most of the trailers were
unoccupied for weeks at a time, the first indication of things gone wrong was the
river of ice greeting the lower-in-elevation office personnel.
Crawling under
the trailer, through a sea of mud once I broke through the skin of ice, I was confronted
with saturated fiberglass insulation that had been wrapped around the plastic piping.
Once I removed it, I was shocked (quite literally) by the underlying heat tape.
After a quick crawl, well—more like sliding along on my back given the quarters
being too cramped for crawling—I found the offending extension cord on the opposite
side of the trailer and unplugged the darn thing. Lesson learned: always look first
for unknown hazards!
Back to the
mud slide. Once I uncovered the pipe, I realized the break wasn’t due to freezing;
it was from the heat tape overheating and subsequent blowout of heat-stressed plastic
tubing. The heat tape itself was blackened and had apparently been in place for
many years, given its cracked and missing outer jacket.
The weird piping
created a challenge for repairs. I picked up a few heat tapes prominently displayed
behind the supply house counter and a box of foam cell insulation that would look
one heck of a lot more professional once the piping was covered. Back to the farm!
Once there,
pipe repairs were made and new heat tape secured—just like the other one too—with
the heat tape wrapped in a spiral pattern and then reversed to overlap its way
back to use up the excess. And, no doubt, history would have repeated itself except
for one thing. As I was sitting in the truck with the heater running full-blast,
I gave my thawing fingers a task—to see if they could unfold the instructions.
Like most trades-folk, I read instructions after installations! There it was in
black and white—warning: FIRE HAZARD—do not allow heat tape to overlap or cover
with insulation. I had to redo my own work at my own expense. Another graduate
course in the School of Hard Knocks!
Which brings
me back to the question posed by a first-time homeowner. She asked about applying
heat tapes on water lines in an unheated crawl space at her vacation home.
“I’ve never
owned a house before and currently live in an apartment. I was hoping not to have
to drain the pipes and just leave the heat on a low temperature. Would I need to
insulate the pipes? It is a small house with a crawl space. What about the ‘heat
tape’ method of protecting the pipes?”
As I explained
to her, water lines in the crawl space can be insulated, which will help to avoid
condensation dripping during the summer and provide slight temporary protection
from short-term freezing temps in the winter.
Continued exposure
to sub-freezing temps will result in frozen pipes and the potential for damage.
If the crawl space can’t be adequately protected, you can heat-tape the water lines.
A word of caution,
however. Not all heat tapes are created equal and most present a potential fire
hazard if they are not installed and used according to the instructions. The heat
tape we use has a braided stainless steel exterior jacket housing a carbon-based
inner core that self-regulates its heating. In other words, it only warms up as
temperatures fall below 45°F and only where needed along its length. It can be
overlapped and insulated without creating a fire hazard. Most cheap heat tapes
can’t be overlapped or insulated because they overheat and pose a real risk for
fire. Heat tapes must be plugged into a GFCI circuit.
The Consumer
Product Safety Commission estimates about 2,000 fires, 10 deaths and 100 injuries
involving heat tapes occur each year.
Dave Yates owns F.W. Behler, a contracting company in York, Pa. He can be reached by phone at 717-843-4920 or by e-mail at behler@blazenet.net .
Also read the Consumer Product Safety Commission article: New Electric Heat Tapes Help Prevent Fires: Safety Alert