Cold Weather Nightmares; Pipes That Go Bust In
The Night:
Sometimes pipes turn out to be more like
nightmares. Hard cold snaps will tend to hit
local pipes hard. Some will freeze up and then
later thaw on their own but others will freeze
and burst while still others will survive
because owners are smart enough to allowed taps
to drip overnight or take other temporary
precautions. Don't expect a pipe to be forgiving
twice (copper tubing will usually allow one
freeze but burst the second time.) Consider too
that next time there is a hard freeze you may
not be home to take precautionary action.
Before the next siege of cold weather, remember,
there are preventive steps you can take for
pipes that have been frozen once and survived.
Start at any fixture that wouldn't produce
water. First, you will want to find out exactly
where the pipe was frozen. This is the spot
around which protection must be applied. If the
pipe actually burst in the past and was
repaired, there will probably be fresh solder
(which is bright silver in color) at the repair
site and cleaned copper around the solder.
Pipes in a draft almost always freeze, so
locating the source of the draft and blocking it
is important. In a crawl space or basement, look
for loose fitting window frames, spots where the
foundation wall meets the wood framing, spaces
around the ends of floor joists, and any small
cracks or holes. Eliminate these sources of air
by stuffing them with expanding foam or even
fiberglass insulation, sealing with duct tape or
any caulking. Even old rags or newspapers will
do in a pinch.
Protecting the pipe itself is also important.
Regular 3 1/2 inch thick foilfaced fiberglass
blanket insulation is about as good a pipe
insulation as any specialty product. It is also
usually easier to apply, especially around bends
and fittings. Cut a blanket into strips about
four inches wide, fold the strips around the
pipe and tape it securely. (Don't skip hard to
reach sections, as these are often where a
freeze is likely to occur.) Use duct tape; one
or two roll usually will do an entire house.
Approximate material cost for a crawlspace job:
$20.
In some extreme situations it may be necessary
to reroute the pipes to prevent them from
freezing. Plumbing fixtures on outside walls are
often connected by "vulnerable" pipes running
within the outside walls. If these have frozen,
have a plumber cut off pieces in the walls and
reroute new pieces through the floor. Naturally
this is easiest with first floor fixtures.
Occasionally a pipe that runs in an outside wall
to a second floor fixture should be rerouted to
the inside of the finished wall surface.
Pipes that run through or near overhangs often
freeze because these "soffit" areas (the
horizontal underside of eaves) tend to be very
drafty. In this case a pipe can be protected by
removing the underside of the soffit, wrapping
the vulnerable pipe and then stuffing the entire
area with fiberglass or foam to minimize air
currents. The underside should then be
reinstalled, usually with a lot of caulking at
all the joints. WARNING: It is not recommended
that unskilled amateurs do any pipe rerouting,
soldering or fitting.
Pipes in old turn of the century frame houses
(which usually have hollow walls without
insulation and a million points where air can
enter) and houses with crawl space will often be
vulnerable even after all attempts have been
made to seal out the air and wrap the pipes.
Consider wrapping the vulnerable sections of
piping with "heat tape" miniature electric
heaters in plastic flat wire and then insulating
over the heat tape with fiberglass or another
form of insulation. The tapes contain a
thermostatic switch that provides a trickle
current of electricity to warm pipes when the
water temperature drops to about 34 degrees.
They are usually wound around a pipe. Care must
be taken not to overlap any windings lest the
tape itself can burn.
Heat tapes should always be attached to a
permanent source of power. They are often
applied in inaccessible locations and attached
via extension cords or even multiple cords. If
your pipes depend on a heat tape, provide them
with a permanent source of power the cords can
be unplugged inadvertently and never reattached.
Heat tapes cost around $1.50 per foot; they come
in lengths of 3, 6, 9, 13 and 15 feet and are
available from most hardware stores. Look for an
Underwriters Laboratory label to make sure the
product has been tested.