Pex in attic

[MJ Inspections]

Should pex water supply lines in attic be insulated through its entire length in the attic?

The builder insulated about 6 feet of the lines from the water heaters located in the attic but did not insulated the entire lengths.

thanks,

Mark J.

[Jerry Peck]

Should pex water supply lines in attic be insulated through its entire length in the attic?

The builder insulated about 6 feet of the lines from the water heaters located in the attic but did not insulated the entire lengths.

thanks,

Mark J.

Mark,

It would be EXTREMELY helpful if you provided your location as something other than: Location n

"n" = north? North Pole maybe? How are we supposed to answer a question based on freezing when we don't know where you are.

Here are two answers:
- 1. If in South Florida, no, not necessary.
- 2. If in Alaska, yeah, you better insulate those pipes.
- 3. If you are somewhere between 1. and 2., then the answer is "maybe".

[Gary Burnett]

.....and if you're in Texas and want cold water during the summer you had better insulate them.

[Terry Beck]

Depends on how often the attic is exposed to freezing temperatures. I'm in Montana, therefore it is a serious issue. Have seen plumbing in the attic a couple of times, and insulated or not, there has been or will be leaks at some point in time. Some winters are mild, and a homeowner might get lucky. It might get below freezing for a bit and not freeze everything up right away, but every few years we get an extended blast of artic weather for a couple of weeks that send the temps to -20 and below to 2 or 3 weeks. Homes at higher elevations get extreme cold weather more often. Don't care how much insulation you have, is never a good idea especially if in a northern climate zone. Insulated or not, I will always write up plumbing in the attic as a serious concern.

But hey - what about the proposed requirement for fire sprinkler systems in all new residential construction???? You will have to run plumbing for sprinkler heads above all the ceilings. Montana decided to not adopt that part of the IRC on last go-around, for several reasons. General contractors, architects, and plumbers that do residential construction are not used to designing attics for water supply. It can be done - conditioned attics, but will require some thought and planning to design the attic as some sort of heated space.

[Scott Cook]

By the IECC 2012 code, I think all hot water service piping outside the conditioned space must a minimum or R-3?

[Larry Morrison]

PEX-Type is forgiving when it freezes as far as breakage...But insulating an exposed water line does little to keep it from freezing. Insulation only slows the time when it will freeze after the water is not running through the pipe.

Such as at night, if the attic Temp is 15 deg F. It may give it an extra hour before it freezes solid. Also an insulated pipe after it has frozen, will take longer to thaw also after the attic gets above freezing.

The best practice if water lines are run in the attic is to keep them close to the ceiling with little or no insulation under them and the majority of the attic insulation on top of them. This will let the heat of the house keep them above freezing. In a home, that for what ever reason water pipes are in the attic (retrofit from PB is common here in my area) It is best to remove the insulation under the pipes and create a "tent" over them with insulation.

In walls, the rule of thumb when insulating, if you can’t get the majority of the insulation behind the pipe, do not insulate on the living side where the pipe is. The idea is to at least have the heat of the home keep it from freezing.

The real problem locations are in areas that have climates like where I am. We have palm trees but we also get below freezing. Plumbers take a lot more chances here than say in the colder areas of UT, where they would hang them for not protecting against the cold.

[Gregory Booth]

Depends on how often the attic is exposed to freezing temperatures. I'm in Montana, therefore it is a serious issue. Have seen plumbing in the attic a couple of times, and insulated or not, there has been or will be leaks at some point in time. Some winters are mild, and a homeowner might get lucky. It might get below freezing for a bit and not freeze everything up right away, but every few years we get an extended blast of artic weather for a couple of weeks that send the temps to -20 and below to 2 or 3 weeks. Homes at higher elevations get extreme cold weather more often. Don't care how much insulation you have, is never a good idea especially if in a northern climate zone. Insulated or not, I will always write up plumbing in the attic as a serious concern.

But hey - what about the proposed requirement for fire sprinkler systems in all new residential construction???? You will have to run plumbing for sprinkler heads above all the ceilings. Montana decided to not adopt that part of the IRC on last go-around, for several reasons. General contractors, architects, and plumbers that do residential construction are not used to designing attics for water supply. It can be done - conditioned attics, but will require some thought and planning to design the attic as some sort of heated space.

...........most residential systems I've seen use side wall heads and have no sprinklers in cold attic.........Greg.

[Lon Henderson]

"Texas" covers a lot of country. In Brownsville or Laredo, run that PEX any way you like. In Amarillo or Dalhart, you're better off not putting plumbing in the attic at all. In Dallas or Odessa, keep it on the ceiling with insulation on top, and you'll probably be fine.

I have a mother-in-law apartment (with mother-in-law) in my barn above the stalls. The bath is directly above the stalls. I created a "soffit" compartment to hold the bath plumbing and plumbed it with PEX. The PEX is close to the bath floor. The bottom of the compartment has ten inch batts for insulation. I ran a duct from the furnace into the space. The first cold spell, the plumbing froze. Luckily, PEX doesn't break easily. I added an inline duct fan to try to push more warm air from the furnace into the space. The plumbing still froze, but the inline fan only ran when the furnace was on. So, I cut the duct from the furnace, so that it draws from the warm utility room. I put the fan on a thermostatically controlled switch so that anytime the compartment gets below 38 degrees, the fan starts pushing warm air into the space. So, far this winter, no problems until two weeks ago when the cold line froze. Sheesh, now I have to revisit this problem again. I've considered adding something like a baseboard heater into the space, but it's a small space about 16" high and I have some concerns about confining an electric heater into a small out-of-sight space. So, the point of all this is.... plumbing in attic type spaces in cold climates is problematic from the start and should be avoided.