Cold Weather Residents. . . Frozen/Burst Pipes

[RNajarian]

A few questions for the denizens of cold weather.

I have a fire suppression system in my garage. It is a set of 1 inch copper pipes in the attic connected to frangible bulbs that will burst at 175° and put out a fire.

Over the summer I did some work up in the area where the pipes are and placed a wireless thermometer to monitor the attic temperature during the summer.

I was checking the thermometer today and noticed that it read 27°F. Obviously well below the freezing point of water. My concern is that this temperature will conceivably burst the copper pipes and create a nasty flood in my garage.

The system has been in place for over 20 years and it is only recently that I have been monitoring the temperature. So very likely it has become below freezing several times in the past.

The system does have a pressure release valve which will open at 115 pounds per square inch and release water.

My questions are;

1) Am I at risk of bursting my pipes up there?
2) Does the pressure regulator open up and relieve pressure and allow the flow of water which prevents freezing?
3) Would I be wise to shut off the water to the area? By doing this I will prevent any flow of water to go through the system should the pressure regulator open and would that actually make matters worse?

Thanks for your insight I’m just not comfortable with my attic so cold up there.

[Cloggie]

Originally Posted by RNajarian

A few questions for the denizens of cold weather.

I have a fire suppression system in my garage. It is a set of 1 inch copper pipes in the attic connected to frangible bulbs that will burst at 175° and put out a fire.

Over the summer I did some work up in the area where the pipes are and placed a wireless thermometer to monitor the attic temperature during the summer.

I was checking the thermometer today and noticed that it read 27°F. Obviously well below the freezing point of water. My concern is that this temperature will conceivably burst the copper pipes and create a nasty flood in my garage.

The system has been in place for over 20 years and it is only recently that I have been monitoring the temperature. So very likely it has become below freezing several times in the past.

The system does have a pressure release valve which will open at 115 pounds per square inch and release water.

My questions are;

1) Am I at risk of bursting my pipes up there?
2) Does the pressure regulator open up and relieve pressure and allow the flow of water which prevents freezing?
3) Would I be wise to shut off the water to the area? By doing this I will prevent any flow of water to go through the system should the pressure regulator open and would that actually make matters worse?

Thanks for your insight I’m just not comfortable with my attic so cold up there.

Yes, you are at risk.

I lived for a fair amount of time in Canada and have seen copper pipes burst when frozen. Not good.

Most Canadian systems that run in areas likely to be frozen are dry with a shutoff valve which only opens up when the fire suppression system goes off (when there is a fire).

More complex for sure, but you don't want to shower things with cold water....

D.

[javadog]

1 Yes
2 maybe
3 I would

https://www.jlconline.com/how-to/plumbing/understanding-how-water-pipes-freeze_o

[stomachmonkey]

Shutting off the flow is only half of it.

Unless you bleed past the valve the pipes still contain water.

Since it seems you have access to the pipes just trace wrap them.

Do it once and forget about it.

The only risk there is if you loose power but if you have a gererator you are good or can still close the valve and bleed if necc.

https://www.amazon.com/heat-trace-cable/s?k=heat+trace+cable

The other option is an oil filled stand alone radiator in the attic.

Thats what I use in my garage when freezing temps are predicted.

[RNajarian]

Ok thanks guys,

I guess I’ve dodged a bullet for the 23 years the system has been in place.

I’ll shut off the water (I’m glad I put the shut off valve in last summer), and open the pressure relief valve to expel water.

[Porchdog]

If 27° is the low and you aren't maintaining that temperature for a long period of time I wouldn't expect it to freeze.

I have lots of experience with freeze-ups in sprinkler systems, but not in southern California.

Those pipes typically need to be protected from freezing temperatures. When the pipes can't be kept warm, the contractor will install either a dry pipe system or a system filled with antifreeze. Residential systems would generally be antifreeze. If that's what you have, there should be signage at the main valve. That antifreeze also needs to be maintained - does your system get inspected?

Here in the northeast we have freezeups every time there are extended periods of cold temperatures. Either improperly installed or poorly maintained systems are the ones that freeze. When they freeze, nothing happens. When they thaw, that's when you get the flood. Usually the heads (the part with the glass bulb) break first. I have also seen broken fittings and split pipe. Ice will create pressure in the thousands of PSI. The pressure relief valve won't help.

https://homefiresprinkler.org/living-with-fire-sprinklers/#:~:text=Fire%20sprinklers%20require%20almost%20no ,valve%20in%20the%20ON%20position.

[cockerpunk]

1. yes
2. probably not
3. yes

[Evans, Marv]

I tend to like "stomachmonkey's" heater suggestion - simple & effective.

[Porchdog]

Originally Posted by RNajarian

Ok thanks guys,

I guess I’ve dodged a bullet for the 23 years the system has been in place.

I’ll shut off the water (I’m glad I put the shut off valve in last summer), and open the pressure relief valve to expel water.

If that system is to code it should have a main shut off and alarm valve. There should also be one or more drain valves. You want to shut it off and drain it. Even without pressure, the residual water can freeze and cause damage.

[masraum]

Originally Posted by stomachmonkey

Shutting off the flow is only half of it.

Unless you bleed past the valve the pipes still contain water.

Since it seems you have access to the pipes just trace wrap them.

Do it once and forget about it.

The only risk there is if you loose power but if you have a gererator you are good or can still close the valve and bleed if necc.

https://www.amazon.com/heat-trace-cable/s?k=heat+trace+cable

The other option is an oil filled stand alone radiator in the attic.

Thats what I use in my garage when freezing temps are predicted.

That sounds like the way to go.

[RNajarian]

Thanks everyone

The system was put in 2003 so who knows what the codes in LA were back then.

I have since put in a water shut off for the system.

Currently the water is shut off and the main drain is open.

That should buy me some time

[1990C4S]

Chromalox heated lines inside foam insulation. Plug it in when it's cold. That's what I've installed at a Ford's water treatment plant.

Or just buy eaves heating lines , wrap the pipes, and plug them in.

[john70t]

City ground supply water below the frost line (a constant 40-50deg) is usually moving.
It will transfer heat of the line to all the nearby branches before loosing heat to ground and pipes exposed to air.

A pipe on the ceiling of an unheated and un-insulated separate garage, is the worst possible place for expecting natural heating during severe local frosts.

[flatbutt]

Originally Posted by 1990C4S

Chromalox heated lines inside foam insulation. Plug it in when it's cold. That's what I've installed at a Ford's water treatment plant.

Or just buy eaves heating lines , wrap the pipes, and plug them in.

My suggestion as well.

[NY65912]

Heat trace the lines.

[Porchdog]

It seems like it would be a rare instance to be below freezing in Southern California.

If that doesn't happen most winters, I would just drain the lines for the rare freezing events.

https://www.currentresults.com/Yearly-Weather/USA/CA/Los-Angeles/extreme-annual-los-angeles-low-temperature.php

As I posted above, the Code solutions are anti-freeze and dry systems. I have seen heat trace used, but that introduces it's own problems. In any case, I wouldn't wan to leave it powered up all year and if you can remember to plug in the heat trace, you can remember to drain the system.

[stealthn]

All good stuff, yes heated covers with battery backup, or look at replacing water with another solution/chemical.

[john70t]

What would chemicals do to the pipe joints?

[Porchdog]

Fire code and possibly local codes have the rules for using anti-freeze. It needs to be an approved type, you need the proper valve to prevent backflow into the domestic water supply, You need the proper relief valve (since it has more thermal expansion than water), You need the correct injection pump to fill the system.

If you want to go that way, you probably need a sprinkler contractor. Don't be surprised if they refuse to work on it unless it is up to code.

Lots of liability risk in the fire sprinkler business. Insurance isn't cheap. Probably need to be licensed in CA.

[Bob Kontak]

Originally Posted by Porchdog

If 27° is the low and you aren't maintaining that temperature for a long period of time I wouldn't expect it to freeze.

+1

The pipe will not let it freeze as the water wants to expand when it reaches freezing temps but it is held in place (Yeah, I watch YouTube).

I've mostly lived in the north and freezing pipes occur way south of 27F. However I would wrap as suggested for peace of mind.