Best way to keep pipe from freezing

[jeffg]

I have a 30x30 detached shop that previous owner built. There is a single outdoor spigot next to the rollup door that comes up thought the slab and then has an elbow out through the exterior wall. The slab penetration is about 8 inches away from the wall and comes up through a 2" PVC pipe that runs down about 4 feet to the buried water line. I attached a drawing to better explain.

This winter has been unusually cold. Traditionally I would close the feed valve to this spigot and drain it to prevent freezing, but my wife brought home some ducks last summer and we need the spigot to fill their water.

Up until now, I have just keep the heat on in the shop to prevent the pipe from freezing and that has worked fine, however the shop is obviously not well insulated as the heat runs often and my gas bill has been very high.

A neighbor suggested that some heat tape and insulation would be a better method to use, but I haven't found any commercial heat tape that would be short enough. There is only about 10 inches of pipe that I can get to, as the PVC conduit is too tight to the pipe to work in.

I don't think that just insulating the pipe would be good enough as the exterior spigot will still get freezing cold.

Other than just leaving the heat on in the shop and paying the gas bill, does anyone have a good idea on how I can keep this small piece of pipe from freezing.

 

[The Cobbler]

I have a similar situation.
I bought a section of EASY HEAT self regulating heat trace on EBAY
My plan is to feed that into a pc of 3/8 copper tube soldered (closed up) on the end away from the plug. I will insert that into the 3/4 pex and use a compression fitting on the plug end of the "probe" .That will heat the inside to keep it from freezing. ( so the 3/8 tube is holding water on the outside rather than the inside of the pipe .
I plan to keep my shop heated but the pex that runs through the slab will likely freeze as 8or so inches is to the outdoors & I'm sure it will freeze. This is my plan as I don't have water hooke dup yet, just the pipe is in and trenched.
you could wrap the tape around the exposed pipe to keep it from freezing and maybe fish beside the supply to keep enough warmth .

Hope I am clear on the concept

 

[The Cobbler]

easy heat trace can be cut to virtually any length (5' minimum I think) and use their special connector for plug. a cap slips over the other cut end

 

[73RR]

How about just building a small box around the interior exposed piping and put a small heater in the box? I just saw an advertisement for a cute little heater that plugs into/hangs from an outlet.
If the interior pipe is kept warm enough then the spigot/valve may not freeze.

 

[shelteredV]

wrap the pipe with a short length of heat tape, leave the extra just hanging around and build a little plywood box to enclose the hose bib and pipe. Simple and cheap.

 

[larry_g]

Here we just let the water run for the few days that are cold enough for freezing the pipes. Run it into a watering tub for the animals and the tub does not freeze over either, win/win.

lg
no neat sig line

 

[jeffg]

Do you think a small enclosure and a heat lamp would work? Maybe even just an incandescent light bulb?

 

[jeffg]

wrap the pipe with a short length of heat tape, leave the extra just hanging around and build a little plywood box to enclose the hose bib and pipe. Simple and cheap.

So just buy the 3' kit and leave the extra hanging? Maybe just fish it down the PVC conduit?

 

[The Cobbler]

if you can, I would push it down the conduit . add some pipe insulation too.
also, some heat tapes can be over lapped on itself, some cannot.

 

[jeffg]

Sounds good, I will give it a try

 

[The Cobbler]

I cant get the heat trace beside where mine goes thru the pad, thus the plan I have

 

[Bondo]

Ayuh,... Alittle more work, but if ya put a frost-proof hydrant where the pipe comes up through the slab, yer troubles are over,....

 

[Sport]

How about a hydrant?

 

[jeffg]

I have frost free hydrants in other parts of the property, but the thought of either trying to install one blind (~4' deep in a small hole), or excavating under the slap sounds risky. I could excavate outside the building and try to put the hydrant outside might work, but not with feet of snow on frozen ground. Maybe in the spring.

 

[hoppsxc140]

Heat tape and a spigot cover on the outside.

http://www.homedepot.com/p/Hard-Faucet-Cover-1981/204759083

 

[86turbodsl]

heat tape is the accepted method of freeze protection on pipes exposed to cold. Mcmaster.com also has a large selection of cut to length tape. We have an outdoor faucet used for horse watering, and i use heat tape with a thermostat on it. works fine down to -20f.

 

[samss]

Raychem w51-6p is what I use for walk-in freezer drain lines. Self regulating, can be overlaped and can be cut to fit. The temp in the freezer is 0 F or below year round.

 

[matt_i]

If it has been fine for some time and you are worried about a snap, I'd go with the steady drip process as suggested.

Then when time permits, install the underground hydrant on a gravel bed. Imo a good idea to use some filter fabric around a "gravel ball" to prevent the soil fines from eventually filling up the gravel bed. Also if running PVC to it underground, I'd use a metal elbow and a metal male pipe thread (ss or brass) to then attach to the PVC. The glue x mpt PVC fitting has an inherent weakness around the end of the threaded area next to the hex.

 

[klassenl]

I vote for the insulated box with a 60w incandescent bulb. Cheap and effective and removable in the summer.

 

[CoogarXR]

Another thing that comes to mind is a heat rod. They are used on mobile home installations where the water pipe comes out of the ground. Heat tape is used above the ground, and a heat rod goes next to the pipe, below the ground, down to the frost line. It's just a long heated rod. I am not sure how hot they get, if you could use one in such a small conduit, but I'll leave that research up to you. Just throwing another idea on the table.

 

[jeffg]

The suggestion to install a hydrant seems to popular. Would you excavate under the slab, or outside the building and just cut and rethread the feed pipe shorter? Cutting and re-threading while 4 feet deep in a hole sounds like a pita. This is all 3/4" galvanized pipe.

I think for now I am going to try and build a small enclosure around the pipe and hang my drop light in it. That sounds about the easiest and quickest thing I could do.