Plastic or brass PEX fittings for crawl space?

[Sh40674]

My sisters house needs re plumbed. Very small house with a deep crawl space (about 4 ish feet). We're in Iowa, so it gets cold. Its well insulted down there and she's never had frozen pipes. That being said she's got old CPVC lines down there that look like they've seen better days so she wants it all replaced. She's on a very tight budget so I suggested PEX for ease and cost.

I've only used brass with the occasional plastic fittings... which one is better for a potential freeze? Like I said it probably will never happen but just in case. I know she can save a lot with plastic so that's attractive. Not sure of our PH level (not in our water report) but the town that connects to ours is above 7, so assuming it's hovering around 7.

Outside of that.. stupid question.. should insulate all the runs of PEX down there?

 

[PlumbNuts]

I run a lot of PEX in crawlspaces and for the last few years I have been using only the plastic fittings and have not had any issues with them.
PEX fittings (plastic or brass) are less likely to freeze and burst because the PEX pipe will actually expand giving the freezing water a place to expand to.
No, it does not get as cold here as often as it does there but we do have our moments.
I would use the plastic fittings.

As far as insulating, you can never go wrong with insulation...
If you did insulate then it would alleviate the concerns over freezing fittings.
Insulating can be a bit costly but it could potentially pay for it's self with hot water energy savings.

This is my personal opinion and it is based on my experience as a Licensed Plumbing Contractor, I am sure there will be a certain individual along shortly with a different opinion.

 

[Sponsor]

 

[wwhitney]

My sisters house needs re plumbed. Very small house with a deep crawl space (about 4 ish feet). We're in Iowa, so it gets cold. Its well insulted down there and she's never had frozen pipes.

When you say it's well insulated, which areas are insulated, and how? And are the crawl space walls all concrete, or are there wood cripple walls on a concrete foundation?

If the walls are well insulated and there's no floor insulation, then the crawl space should be pretty close to indoor temperature just by passive heating from above. The risk of freezing in the crawl space would be very low. Conversely, if the floor is well insulated and there is no wall insulation, then the crawl space temperature will be much closer to the outdoor temperature.

Cheers, Wayne

 

[Jeff H Young]

I run a lot of PEX in crawlspaces and for the last few years I have been using only the plastic fittings and have not had any issues with them.
PEX fittings (plastic or brass) are less likely to freeze and burst because the PEX pipe will actually expand giving the freezing water a place to expand to.
No, it does not get as cold here as often as it does there but we do have our moments.
I would use the plastic fittings.

As far as insulating, you can never go wrong with insulation...
If you did insulate then it would alleviate the concerns over freezing fittings.
Insulating can be a bit costly but it could potentially pay for it's self with hot water energy savings.

This is my personal opinion and it is based on my experience as a Licensed Plumbing Contractor, I am sure there will be a certain individual along shortly with a different opinion.

I like insulating as well and agree with there is some costs you mention saving money on energy the money saved in freeze repair is a lot too.
around here If I repipe with copper in attic (crawl spaces uncommon on homes less than 50 yo) in my area I like to insulate hot and cold helps with noise as well copper is a bit noisy or can be....

 

[PlumbNuts]

I run a lot of PEX in crawlspaces and for the last few years I have been using only the plastic fittings and have not had any issues with them.
PEX fittings (plastic or brass) are less likely to freeze and burst because the PEX pipe will actually expand giving the freezing water a place to expand to.
No, it does not get as cold here as often as it does there but we do have our moments.
I would use the plastic fittings.

As far as insulating, you can never go wrong with insulation...
If you did insulate then it would alleviate the concerns over freezing fittings.
Insulating can be a bit costly but it could potentially pay for it's self with hot water energy savings.

This is my personal opinion and it is based on my experience as a Licensed Plumbing Contractor, I am sure there will be a certain individual along shortly with a different opinion.

Oh also, he is going to want to know every single detail of your home so that he can perscribe to the milimeter exactly what kind and how thick said insulation should be.....

 

[Reach4]

You are supposed to insulate hot lines.

 

[PlumbNuts]

You are supposed to insulate hot lines.

I don't know what county you are in but it is most likely the same.

Copied and pasted from: Residential Guidelines Linn County Building Codes,,,,

"2012 International Energy Conservation Code Residential Construction Effective June 1, 2014 (Revised 3/19/16) Compliance with the 2012 International Energy Conservation Code (IECC) is required pursuant to adoption and as mandated by the State of Iowa Chapter 303, Rule 661-303.2(103A). The following items are a snapshot of some upcoming requirements and should in no way be considered all inclusive:",,,,

"Hot water piping 1) All Paths: Mechanical piping above 105oF or below 55oF shall be insulated to a minimum of R-3. [R403.3] 2) Prescriptive Path: Piping from a water heater to a distribution manifold and/or to fixtures shall be insulated to a minimum R-3. [R403.4.2]",,,

 

[wwhitney]

To be clear, if your crawl space gets below freezing for an extended period, and you have insulated water pipes there with still water, they are still going to freeze. Pipe insulation just slows the transfer of heat, it doesn't prevent it. So it will slow the freezing, and maybe protect the pipes if it only gets below freezing for a few hours.

That's why the ambient temperature in the crawl space matters. Which in turn will depend on the insulation between the crawl space and outdoors, and the insulation between the crawlspace and the conditioned space.

Cheers, Wayne.

 

[JohnCT]

Pipe insulation just slows the transfer of heat, it doesn't prevent it. So it will slow the freezing, and maybe protect the pipes if it only gets below freezing for a few hours.
.

^^^Exactly.^^^

I think some folks confuse the action of insulation with clothing. Clothing prevents freezing because we generate heat internally as long as we're alive. One could insulate to R1000, but eventually the insulated area will reach ambient temperature.

John

 

[PlumbNuts]

Sh40674, I hope that you found the answer to the question that you asked "Plastic or brass PEX fittings for crawl space?"

 

[Sh40674]

Sh40674, I hope that you found the answer to the question that you asked "Plastic or brass PEX fittings for crawl space?"

Sorry, long weekend. Yes I did and thanks guys for the replies!

I understand insulating doesn't prevent freezing but as said, it slows and could make the difference between frozen or not. She has concrete walls, dirt floor, thick Batts of insulation around the walls, and puts Styrofoam over her outside vents in the winter. No insulation on the floor. I think it stays above freezing year round. It survived our winter a few years ago which we had a solid month below 0 so I think that was a great test for it