I have a bathroom sink that's against an outside wall. The vent for the sink
drain goes straight through the wall and then up outside the house to the
eaves. When it gets cold (single digits), the water in the P-trap freezes
into a solid plug and stops the sink from draining. I've put as much
insulation in as I can, but it still freezes when it gets bitterly cold. Any
ideas how I might be able to resolve this without re-routing the vent line
or boxing it in? I've thought about placing a small hot pad around it or
hanging a light bulb near by, but this is a guest bathroom and it's a
pedestal sink, so anything that I put around the P-trap itself would be
visible.

M,

They make heat tape to prevent freezing pipes. Buy some, wrap it around
the trap, and plug it in on cold nights. Changing from a metal trap to a
less heat conductive trap made from PVC might also work. I'm not sure that
heat tape is safe with PVC pipe.

Dave M.

MPost wrote:
I have a bathroom sink that's against an outside wall. The vent for
the sink drain goes straight through the wall and then up outside the
house to the eaves. When it gets cold (single digits), the water in
the P-trap freezes into a solid plug and stops the sink from
draining. I've put as much insulation in as I can, but it still
freezes when it gets bitterly cold. Any ideas how I might be able to
resolve this without re-routing the vent line or boxing it in? I've
thought about placing a small hot pad around it or hanging a light
bulb near by, but this is a guest bathroom and it's a pedestal sink,
so anything that I put around the P-trap itself would be visible.

Leave the door under the sink open on cold nights.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

"MPost" wrote in message
I've thought about placing a small hot pad around it or hanging a light
bulb near by, but this is a guest bathroom and it's a pedestal sink, so
anything that I put around the P-trap itself would be visible.

First step is to decide what is more important. Do you want it to look
pretty or do you want it to work?
Wrap it with heating tape and plug it in.

have you tried letting the water drip through the coldest nights?

"MPost" wrote in message
...
I have a bathroom sink that's against an outside wall. The vent for the
sink drain goes straight through the wall and then up outside the house to
the eaves. When it gets cold (single digits), the water in the P-trap
freezes into a solid plug and stops the sink from draining. I've put as
much insulation in as I can, but it still freezes when it gets bitterly
cold. Any ideas how I might be able to resolve this without re-routing the
vent line or boxing it in? I've thought about placing a small hot pad
around it or hanging a light bulb near by, but this is a guest bathroom and
it's a pedestal sink, so anything that I put around the P-trap itself would
be visible.

MPost wrote:
I have a bathroom sink that's against an outside wall. The vent for
the sink drain goes straight through the wall and then up outside the
house to the eaves. When it gets cold (single digits), the water in
the P-trap freezes into a solid plug and stops the sink from
draining. I've put as much insulation in as I can, but it still
freezes when it gets bitterly cold. Any ideas how I might be able to
resolve this without re-routing the vent line or boxing it in? I've
thought about placing a small hot pad around it or hanging a light
bulb near by, but this is a guest bathroom and it's a pedestal sink,
so anything that I put around the P-trap itself would be visible.

Assuming that the majority of the cold air isn't coming down the vent and
that you have already isolated the metal vent pipe from the metal P-trap,
try this....

http://www.plumbersurplus.com/Produc...7&Cat=0&Mfr=42

I don't see the problem. Ice from a sink ptrap makes yummy drinks. You
should consider yourself lucky!

Joseph Meehan wrote:
MPost wrote:

I have a bathroom sink that's against an outside wall. The vent for
the sink drain goes straight through the wall and then up outside the
house to the eaves. When it gets cold (single digits), the water in
the P-trap freezes into a solid plug and stops the sink from
draining. I've put as much insulation in as I can, but it still
freezes when it gets bitterly cold. Any ideas how I might be able to
resolve this without re-routing the vent line or boxing it in? I've
thought about placing a small hot pad around it or hanging a light
bulb near by, but this is a guest bathroom and it's a pedestal sink,
so anything that I put around the P-trap itself would be visible.


Leave the door under the sink open on cold nights.


On a pedestal sink Joseph?

That's about as helpful as my suggesting to him that he leaves a small
stream of hot water running all night. G

Jeff

Speaking of freezing things:

http://home.comcast.net/~jwisnia18/temp/snow_text.html


Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"

Jeff Wisnia wrote:
Joseph Meehan wrote:
MPost wrote:

I have a bathroom sink that's against an outside wall. The vent for
the sink drain goes straight through the wall and then up outside
the house to the eaves. When it gets cold (single digits), the
water in the P-trap freezes into a solid plug and stops the sink
from draining. I've put as much insulation in as I can, but it still
freezes when it gets bitterly cold. Any ideas how I might be able to
resolve this without re-routing the vent line or boxing it in? I've
thought about placing a small hot pad around it or hanging a light
bulb near by, but this is a guest bathroom and it's a pedestal sink,
so anything that I put around the P-trap itself would be visible.


Leave the door under the sink open on cold nights.


On a pedestal sink Joseph?

That's about as helpful as my suggesting to him that he leaves a small
stream of hot water running all night. G

Jeff

I guess "I've put as much insulation in as I can" confused me. In any
case, I sure would want my guest bath to be a little warmer than that. It
sure would keep the guest on their toes. :-)


Speaking of freezing things:

http://home.comcast.net/~jwisnia18/temp/snow_text.html


Jeff

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

I have a very similar problem today; I thought I was doing the right
thing using the slow drip method to not have pipes freeze, but I now
have a leak from the end of the P trap. I'm wondering if I should try
to put hot water in the sink and if breaking up that ice will ease the
pressure on where the trap meets the next pipe.

Is it typical for water to stay standing in the P trap? I would guess
so, lots of rookie questions I have here.

Don't mean to hijack this thread, just joining in on the fun g.
jtr

Is it typical for water to stay standing in the P trap? I would guess
so, lots of rookie questions I have here.


Yes, it's normal for water to stay in the P trap. That's what it's
for. If this is an ongoing problem, one half-assed solution is to
keep a gallon of RV antifreeze nearby, and pour about 8 oz down the
drain on cold nights, after you're done with everything else.

Yes, it's normal for water to stay in the P trap. That's what it's
for. If this is an ongoing problem, one half-assed solution is to
keep a gallon of RV antifreeze nearby, and pour about 8 oz down the
drain on cold nights, after you're done with everything else.

I would suggest salt poured down the drain. Been there, done it.

"DD" wrote in message
...


Yes, it's normal for water to stay in the P trap. That's what it's
for. If this is an ongoing problem, one half-assed solution is to
keep a gallon of RV antifreeze nearby, and pour about 8 oz down the
drain on cold nights, after you're done with everything else.

I would suggest salt poured down the drain. Been there, done it.



Salt might be okay with plastic pipes. I would avoid it's use with metal
pipes.