# Pipe insulation: Foam, Rubber, Other?



## IckesTheSane

I'm planning on insulating some of my pipes and am wondering what the best kind of insulation is. I was checking it out at the hardware store, and there were a couple different kinds; a lightweight foam, similar to a funoodle pool toy, a heavier and more expensive foam rubber, similar to what I've seen used on heat pump lines, as well as some foil backed fiberglass wrap. I'm thinking of using the foam rubber, but only because it's a) more expensive and b) it's what they use on heat pump lines. I'm assuming they would use the most efficient stuff for something like that, and that the cheaper stuff is cheaper for a reason.

Basically, which has the better R-value? 

Or is there something else I should consider?

Thanks in advance!


----------



## BobVilla

*R-Value*

The R-Value is basically the same for all the insulation types you mentioned. The foam insulation is extremely flamable :furious:, so its not recommended to put foam insulation near your hot water heater (just to be safe):laughing:. Foam insulation also shrinks when it is put on a hot pipe, which could leave spaces in between pieces. Rubber is good for cold pipes, but is a more expensive insulation. Fiberglass is not flamable and is usually the cheapest. Check out for pricing on foam, rubber, and fiberglass insualtion.


----------



## HarryD

PE Foams are fire retardant, but rubber creates a very toxic black smoke which contains halogen.

PE is suitable for temperatures up to 250 F (120C).

Rubber shrinks by more than 25% at the boiling point of water; PE only 3%.

Rubber for cold pipes is not a good idea either as the inevitable condensation reacts with the chloride to create hydro-chloric acid and that corrodes the pipes.

Fiberglass? You mean "the other asbestos"? You can't use that for cold applications as the condensation will be absorbed by the material.

Use PE Foam. Lasts forever. Safe and clean and non-toxic.

Good luck,

Harry


----------



## Marvin Gardens

Polyurethane is the best for pipes. It should be closed cell to keep from absorbing moisture. Most of the time you only need to insulate the warm pipe unless you have freezing issues.

I have used the gray formed pipe (polyurethane) at the local hardware store for decades and it has worked fine for temperatures ranging from -30 to 160.

My solar hot water system is frying my insulation but it is at 212 on really sunny days and even though it is rated to 230 it is melting.

As for worrying how the stuff will do in a fire that is not really an issue. I mean, what are you doing in a house that is on fire anyhow????


----------



## protechplumbing

PE for cold pipes. Will last about 6 years in UV.

Synthetic rubber(armaflex, armacell) for really hot pipes. It will get brittle and looses R-value with time. Will last about 10 years in UV.

Great stuff foam for either if you don't mind working on it for days. It does have the best R-value though and it heat and flame resistant. Very messy and doesn't look good at all.

Fiber glass is time consuming. has the poorest R-value, and it gets worse if pipes form condensation or are exposed to the elements. It is by far the most heat, flame and U.V. resistant. It needs to be coated with aluminum tape and then duct mastic to make it weather proof. If you don't mind raping every thing 3-4 inches thick then taping and coating, it will handle the most extremes and last the longest. 

Their is also cork tape and foamed glass. I wouldn't recommend either.


----------



## IckesTheSane

Holy thread necromancy, Batman!  I forgot all about the thread until I got an e-mail that someone responded!

And thanks for the responses! For posterity, I did use some PE foam to insulate some of the piping right after the heater. I still haven't finished since the pipe size shrinks once it starts branching out through the house, and I didn't get any of that size yet. 

Since a few people mentioned freezing and fire issues, I'll just throw out there that it's an electric heater in the unfinished (but insulated) part of the basement. My main reason for wanting to insulate it is because out hot water heater is set at a pretty low temp, and I want to make sure as much of the heat makes it to where it's being used.

Thanks again!


----------



## HarryD

*PE Foam lasts the longest*



Marvin Gardens said:


> Polyurethane is the best for pipes. It should be closed cell to keep from absorbing moisture. As for worrying how the stuff will do in a fire that is not really an issue. I mean, what are you doing in a house that is on fire anyhow????


With all due respect, Marvin, but I think you may be confused about the PU foam. PU is not completely closed cell (at the most 95%). Put some water on it and see what happens.

One more thing, bacteria are a problem with PU foams, hence there are PU slabs covered with AgION treated aluminum foil. Rubber comes now also in an anti-microbial rubber. But PE is completely mold, mildew, and bacteria resistant.

As for fire, unfortunately, most if not all people who die in a fire have been overcome by the (toxic) smoke. Smoke kills: You can't find the exits, and you can't breathe if it is a rubber fire (rubber insulation contains chloride). PE has an F2 fire rating, and the toxicity and opacity of the fumes are so low that the PE foam can safely be used (and is used) in for instance Airbus aircraft.

As for the temperature range, try using chemical cross-linked PE foam, resistant to 240 degrees F / 120 degrees C.

And regarding UV, no plastic (and also not rubber) likes UV. Cover it with a flexible paint or a UV resistant PE film (some PE foams come with such films).

Greetings,

hmcl


----------



## raskgle

*need to know*

I really don't understand what is pe, will be running water to a work shop. `
Raskgle


----------



## HarryD

raskgle said:


> I really don't understand what is pe, will be running water to a work shop. `
> Raskgle


PE stands for poly-ethylene. The insulation made of low density expanded PE (poly-ethylene) is 100% closed cell, and has a constant lambda value, meaning that the insulation applied today, has the exact same performance 25 or 50 years from now.


----------



## Densec

*PE Foam*

Is PE Foam good for steam pipes from a furnace or are the pipes too hot?

Thanks

Dennis


----------



## HarryD

Densec said:


> Is PE Foam good for steam pipes from a furnace or are the pipes too hot?
> 
> Depends.... There is cross-linked PE foam (yes, would be OK), and there is non cross-linked PE foam (nah, not really possible).
> 
> With cross-linked foam, the PE molecules are bonded to one another. That results in a higher resistance against chemicals, as well as a higher temperature resistance: Good for up to 110 centigrade / 230 Fahrenheit and a peak of some 10 C / 20 F higher.
> 
> With non cross-linked foam, the temp resistance is 95 C / 203 F.
> 
> So yes, if you use cross-linked PE. You can recognize cross-linked PE as it has a finer cell structure, and it comes in flat shapes (which, of course, can be made into a tube or a sleeve). If you see a tube or a sleeve made out of one piece of poly-ethylene foam (without it being glued together) it is most likely non cross-linked.


----------



## sold5

*Polyurethane sheet when wet*

Hi,

You all seem knowledgable on insulation materials so I have a few questions that have been batted around on another forum if you dont mind:

1) Does PU sheet insulation lose its lambda (k) value when it gets wet?

2) Does PU sheet insulation break down and disintegrate when it gets wet?

3) Is pentane the blowing agent for PU sheet insulation and if so, does the lambda value depend on the pentane being in the sheet - ie does it lose a significant amount of insulation value over time?

Thanks!

Steve


----------



## piste

*Conclusion?*

Greetings all,
I am basically in the exact same situation as the OP....found this thread...and want to confirm I got the right conclusion here as there is some highly conflicting information.

My situation is that my hot water heater is in a utility room off a finished basement. But also hot water system has a hot water recirculator in it...so my hot water feed pipes and the return pipes that are in the utility area are throwing off (and therefore wasting) heat in the utility area to the point that the utility area is warmer than the finished basement any time of year... quite warm. So I want to insulate all the hot water feed and return pipes I have access to starting right at the hot water output from the water heater. Been to Lowes/Home Depot and seem to find the three stated options in preformed pipe insulation: 1) PE foam, 2) rubber, and 3) fiberglass with tape covering around it...and I'm trying to figure out what is the "best" way to go. "Best" in my case means getting the highest R value I can in something that will not be or become problematic for any reason...ie. condensation/mold, melting at the hot water output area from the tank, etc.

My conclusions and questions from this thread are:
1) that PE Foam is the way to go. How does it's R value stack against rubber or the fiberglass options? Will I be ok from a melting perspective putting it right at the hot water tank hot output?http://www.homedepot.com/Building-M...splay?langId=-1&storeId=10051&catalogId=10053
2) Rubber could melt and/or throw off toxic stuff so best used only on cold water pipes? http://www.armacell.com/www/armacell/armacell.nsf/ansHTMLSeitenLookUp/USA_Frame?OpenDocument
3) Fiberglass...not sure what to conclude on this other than avoid for cold water which is not something I'm considering. http://www.homedepot.com/Building-M...splay?langId=-1&storeId=10051&catalogId=10053
.
Economics....
PE Foam is cheapest...~$2 bucks for 6 feet
rubber a bit more money....~$5 bucks for 6 feet
fiberglass sections pre-wrapped with tape ...~$5 bucks for 3 feet 

HELP!!!.......


----------



## danstheman

*Foam, hands down*

Definitely use the *self-sealing* foam pipe insulation. That's the kind with adhesive pre-applied and covered with plastic strips, so after you install it you pull off the strips and stick it together, to eliminate the gap where the pipe is slit. It costs a little more but will be much more effective. If you want to be really thorough, tape all the connections between pieces of pipe insulation. Don' forget to insulate at least the first 6 feet(from your water heater) of your cold water pipes as well, along with anything else connected to the water heater that feels warm(i.e. electrical conduit, TPR valve)

Foam always has a higher R-value than fiberglass, and since fiberglass is not an air barrier, it would need a completely air-tight covering to achieve it's stated R-value.

As far as which type of foam has a higher R-value, I have spent many hours in vain trying to figure this out and can't get accurate information about R-values for pipe insulation anywhere. Perhaps that's because the R-value standard cannot be applied to pipe insulation due to the testing methods. The closest I've come to this information is here, but the information is inconsistent and doesn't make sense. 
In any case I would go with the cheaper polyethylene foam, since I doubt there is much difference R-value and it makes intuitive sense that it would be more durable- rubber hardens over time, but plastic in most forms is extremely stable.

Neither type is going to melt at any temperature your water heater is going to reach. Other posters were referring to smoke hazards in the event of a house fire.



piste said:


> Greetings all,
> I am basically in the exact same situation as the OP....found this thread...and want to confirm I got the right conclusion here as there is some highly conflicting information.
> 
> My situation is that my hot water heater is in a utility room off a finished basement. But also hot water system has a hot water recirculator in it...so my hot water feed pipes and the return pipes that are in the utility area are throwing off (and therefore wasting) heat in the utility area to the point that the utility area is warmer than the finished basement any time of year... quite warm. So I want to insulate all the hot water feed and return pipes I have access to starting right at the hot water output from the water heater. Been to Lowes/Home Depot and seem to find the three stated options in preformed pipe insulation: 1) PE foam, 2) rubber, and 3) fiberglass with tape covering around it...and I'm trying to figure out what is the "best" way to go. "Best" in my case means getting the highest R value I can in something that will not be or become problematic for any reason...ie. condensation/mold, melting at the hot water output area from the tank, etc.
> 
> My conclusions and questions from this thread are:
> 1) that PE Foam is the way to go. How does it's R value stack against rubber or the fiberglass options? Will I be ok from a melting perspective putting it right at the hot water tank hot output?http://www.homedepot.com/Building-M...splay?langId=-1&storeId=10051&catalogId=10053
> 2) Rubber could melt and/or throw off toxic stuff so best used only on cold water pipes? http://www.armacell.com/www/armacell/armacell.nsf/ansHTMLSeitenLookUp/USA_Frame?OpenDocument
> 3) Fiberglass...not sure what to conclude on this other than avoid for cold water which is not something I'm considering. http://www.homedepot.com/Building-M...splay?langId=-1&storeId=10051&catalogId=10053
> .
> Economics....
> PE Foam is cheapest...~$2 bucks for 6 feet
> rubber a bit more money....~$5 bucks for 6 feet
> fiberglass sections pre-wrapped with tape ...~$5 bucks for 3 feet
> 
> HELP!!!.......


----------



## piste

danstheman said:


> Definitely use the *self-sealing* foam pipe insulation. That's the kind with adhesive pre-applied and covered with plastic strips, so after you install it you pull off the strips and stick it together, to eliminate the gap where the pipe is slit. It costs a little more but will be much more effective. If you want to be really thorough, tape all the connections between pieces of pipe insulation. Don' forget to insulate at least the first 6 feet(from your water heater) of your cold water pipes as well, along with anything else connected to the water heater that feels warm(i.e. electrical conduit, TPR valve)
> 
> Foam always has a higher R-value than fiberglass, and since fiberglass is not an air barrier, it would need a completely air-tight covering to achieve it's stated R-value.
> 
> As far as which type of foam has a higher R-value, I have spent many hours in vain trying to figure this out and can't get accurate information about R-values for pipe insulation anywhere. Perhaps that's because the R-value standard cannot be applied to pipe insulation due to the testing methods. The closest I've come to this information is here, but the information is inconsistent and doesn't make sense.
> In any case I would go with the cheaper polyethylene foam, since I doubt there is much difference R-value and it makes intuitive sense that it would be more durable- rubber hardens over time, but plastic in most forms is extremely stable.
> 
> Neither type is going to melt at any temperature your water heater is going to reach. Other posters were referring to smoke hazards in the event of a house fire.


Thanks!! Your screen name is appropriate...you ARE the man!! I still haven't finished sealing all my pipes but did end going with the one you recommend. Was told by one guy at Loew's that 1/2" is standard pipe size but those were WAY too tight on my pipes and would not stay stuck. So ended up with 3/4" which have a "slight" bit of extra room..maybe 1/8" or so between but I figure that's fine.

I actually was planning to do some taping as well like you said. Was thinking duct tape would be fine?...or should I get some "special" tape like shown on the site you sent? Alternatively I was thinking of wrapping some foil backed fiberglass around the PE pipe for added measure with ends secured by duct tape. Reason for foil backed fiberglass is...with the hot water recirculator that I have...my pipes stay hot enough such that when I put my hands on the PE that I've put on the pipes near the water heater they still feel slightly warm.
Thanks again!!


----------



## ScottAlbrecht

This thread seems to be the definitive source on pipe insulation! While that's great, it underscores how underdeveloped this market segment is with regards to information. I agree with another, the information is very contradicting. In the interest of providing a better understanding of PE and EPDM rubber pipe insulation, I compared PE and EPDM rubber products from Nomaco, TundraFoam, and Frost King. Nomaco is the highest rated cross-linked PE I found at 210 F and is the only GreenGuard certified product. Of the TundraFoam and Frost King products, I preferred the TundraFoam products. Their EPDM rubber is higher temperate rated and the quality seems better. For example, both their PE and EPDM Rubber come with a tape flap that seals the seam as well as the adhesive in the seam itself. Whether or not this provides a more airtight seal remains to be seen but my guess is it would help eliminate installation errors and holdup better over time. Without a tape flap, I'd consider taping. The Nomaco website provides the most info on their products. They don't sell rubber insulation. The others sell both.


I’m concerned about the following: condensation control, longevity, indoor air quality, heat insulation, and toxicity in a fire in this order. For me, cost is not a factor. Temperature rating is also a consideration but only because I believe a higher rated product likely will last longer and maintain its performance characteristics better. To compare, I looked at information in various forums and contacted the manufactures. None of the manufacturer reps however were engineers; largely sales persons. The wording used and the way in which they responded didn't leave me with much confidence with one exception. That exception however answered largely opposite everyone else. So again who do you believe? Here’s my data:

1.) Condensation Control

+ Rubber will create hydrochloric acid. None of the manufacturer reps knew anything about this and I couldn't find any other information. It'd be great if someone could chime in to confirm or deny this
+ One manufacturer claimed PE was better at moisture control, the others said Rubber is and absorbs less moisture. Is there a difference between cross-linked PE and regular PE?
+ Seems this thread overall believes PE is better for cold pipes; both companies offering EPDM rubber said their rubber product is

My take: datasheets from the manufactures indicate both pass at least some moisture; neither a lot. Each measured this differently so I'm not sure which is better. Sounds like both work unless you believe the hydrochloric acid statement. I'll call this a tie and look at the other factors to decide


2.) Longevity


+ Definitely a disagreement here. Some say PE lasts forever yet the manufactures not only warranty PE for a shorter period but their reps also say rubber lasts longer
+ The reps did not know anything about rubber losing insulation value over time
+ Others say rubber hardens over time

My take: I'm confused why the manufactures don't warranty PE for as long as rubber. I'm guessing this is because rubber deteriorates less when exposed. If exposing to elements such as outdoor use or UV, rubber seems like the way to go. If well protected, both seem to last a long time (30+ years). My feeling is PE will last longer based on possible decline in insulation peformance reported (if true). It makes sense to me that rubber may harden over time. Will non-cross linked PE last longer than rubber on heated pipes given its lower temperature rating though? For cold water pipes, PE but again I feel the data is lacking.

3.) Indoor Air Quality

+ IAQ appears to have been ignored by the industry with the exception of Nomaco.
+ Two of the reps claim their products produce no VOCs
+ These same manufactures did not provide MSDN sheets. When asked, I did get one for their PE product (why no rubber?!). However, the MSDN provided looked minimally filled out so I question how much was really tested.
+ Another industry rep said all products off-gas but as long as they are cured right, it’s not a problem for either PE or Rubber.

My take: both PE and Rubber off-gas a least a little. I can’t imagine any rubber based product not producing anything. I expect rubber to produce more VOCs than PE. To hear two of the reps say their products produce no VOCs whatsoever seems extremley doubtful. Perhaps the level is so low it isn’t a concern but I want to know the specifics. Big kudos to Nomaco for leading the industry here. Since the others provided no information, I can only go with my instinct and say PE will be better. While I don't know, perhaps the Nomaco product is better as well since they at least paid attention.

4.) Heat insulation

+ PE and Rubber have the same insulation properties; at least to start
+ Some say Rubber degrades over time but PE does not
+ One rep had no idea. Another calmed they had never heard of rubber losing insulation ability over time. The last rep confirmed PE doesn’t lose its insulation ability over time
+ Someone on this thread said rubber can shrink up to 25% and PE only 3%. One product rep responded saying the opposite: rubber approximately 1% and PE 3% and only at the upper temperature ratings. 

My take: hard to know what to believe. A higher rated product will likely do better IMO and won't hurt. That said both PE and rubber should be fine considering the rating of even the lower PE variety is 160 degrees F which is still hotter than your typical hot water at 120 F. 
I thought it would be interesting to test so I bought a “stick” of each and took a blow torch to them. I know this isn’t a real exact test but it did provide some data to extrapolate from. Both contain a flame retardant and while both ignited, the flame instantly went out the moment the flame was removed. The PE pretty much melt away while the rubber maintained quite a bit more of its integrity. I didn’t have PEX to try but I am curious how it would do. In any case, I think you can conclude you won’t burn your house down if you run PE right up to your hot water heater though it is true it doesn’t hold up nearly as well to heat as rubber; at least at excessively high temps.

5.) Toxicity during a fire

+ The MSDN sheet for the PEX suggests Nomaco’s product produces very low toxic gas when burned
+ Some claim rubber pipe insulation emits a nasty toxic gas when it burns. 
+ Both of the reps I talked with had no knowledge of rubber producing toxic gas when burned. They further didn’t know what I was talking about when I asked if their product was Halogen free. However, they did say their products are completely safe and do not produce any harmful products when burned. 

My take: I doubt any of the products are better than the PEX; maybe the same. The fact two of the industry reps had no knowledge about claims of rubber emitting toxic gas when burned and didn’t know what I was referring to when asked if their product contained Halogen didn’t leave me with much confidence. To say they produce no harmful fumes when burned seems incredulous. With little additional information, I simply have no idea other than what has already been posted in this thread but my torch experiment did provide some clues. Both produced a white smoke. Both smelled. Doing this outside, I couldn’t tell much of a difference in the amount of smoke produced. I’d lean towards the rubber being worse if I had to choose but it didn't appear to be ghastly different.
My final conclusions? The information is very contradicting so I’m not 100% sure which is absolute "best". It doesn’t sound like you’d go horribly wrong using either. 

I’ll likely use the Nomaco PEX for cold pipes and either the same or the TundraFoam Rubber for hot pipes; leaning again toward the Nomaco


----------



## danstheman

*PEX is a type of plumbing pipe*

I think you may be a little confused. PEX is a type of plastic pipe(which is very common in new construction), not pipe insulation.


----------



## ScottAlbrecht

Confused a little but not so much about the PEX! 

PEX is an acronym for cross-linked polyethylene. It can be made into a foam, the plastic pipe you refer to, or a whole host of other “plastic” products. 

Now whether or not the PEX acronym is avoided when talking about cross-linked polyethylene foam I don’t know. I was just over 10,000 characters and trying to shorten my post.  Thanks for bringing it up. I definitely didn’t want to confuse anyone!

Note, the PE pipe insulation from Frost King and TundraFoam is not cross-linked. I was under the impression the PE pipe insulation from Nomaco was hence the higher temperature rating. However, going back to their website I’m not finding where this is specifically stated. Instead they say they make products made of polyolefin and elastomeric insulations. PE is a polyolefin and rubber is an elastomeric. So I’m definitely wrong there since I didn’t think Nomaco made a rubber pipe insulation and they do. I don’t know why they don’t use the terms PE and rubber but I’ll try to get the story over the next couple of days.

As I’m beginning to understand things better, I did find a couple answers when trying to confirm whether Nomaco’s PE was cross-linked or not. 

The first answer I found explained my torch test. PE is a thermoplastic material. In other words it melts above its rated temperature. Elastomeric (rubber) is a thermoset material and gradually fails above its rated temperature so its temperature rating can be exceeded for short periods of time without it being catastrophic. 

The second answer was in regards to leeching of chlorine and corrosion of the pipes. Apparently both PE and Rubber can emit some Chlorine but the amount released by PE typically won’t do anything. The amount released by rubber can cause a problem in some situations but the Nomaco site implies this is really only a problem with stainless steel products and it doesn’t sound like it would have much of an effect on copper.

Thanks,
Scott


----------



## ProfOlhous

*Just Thanks*

Scott, I just want to say thanks for the depth of your research and extensive reports. Only found this forum about an hour ago, but hope to return the favor someday soon.... For now, can just say that I've had all of these insulations (except cross-linked) working on parts of the same system for 15 years or more, and the Frost King-type PE shrank significantly at temps up to 180F after only a few years. Great amounts of condensation on cold pipes, but no noticable corrosion on copper due to rubber, and rubber has not shrunk nor hardened noticably. Fiberglass used only on hot pipes and seems to radiate least, perhaps because it's the only one with a sealed silver membrane to reduce radiant infra-red in addition to conductive heat losses. Okay, back to work... Best to all.


----------



## ProfOlhous

*Comparison Specs*

Try this url for a pdf containing a pretty useful comparison: http://www.industrialinsulation.com/images/refernce_chart.pdf


----------



## piste

Well I finally found some time to work on adding the foam insulation to some of the pipes coming off my water heater and those part of my hot water recirc system. After adding the foam most areas were still warm to the touch on the foam...Couldn't really find a bigger foam size to fit around the existing foam to double up so to speak...so I'm wrapping the foam with some rolls of 3" fiberglass that is backed with foil. Even with that some areas STILL feel slightly warm to the touch but that's as far as I'm going with it!!! 

I would have thought it would be standard to insulate all pipes that are part of a hot water recirc system even if they run through insulated areas of the house...given they are constantly full of hot water...and maybe it is...but mine are not at all....but you know builders...thus this forum!


----------



## bradatship

*Insulating Hot Water Heat Pipes*

I've been researching pipe insulation for a bit now and this is probably one of the best discussions that I have found, thanks for all of the great information. I have a cape style house and some of my hot water heating pipes run through the unconditioned space behind my upstairs kneewall. There is a minimal amount of foil-backed fiberglass wrapped around the pipes (compressed and tied with strings). I don't think that this is very efficient, what is the best type of pipe insulation to use in this situation? I'm not sure what the exact temperature of the pipes are at this location, I'm guessing around 200 deg F (it's hot water, not steam). Pipes are 1". Thanks!


----------



## Dr. Awsome

This thread has great info on insulation, but I'm a little unclear on whether the electric heaters for pipes are a good option. I need to prevent some pipes that run through a crawl space next to the outside wall of my foundation from freezing.


----------



## drewguy

I agree this is a great thread, and I stumbled across it on google looking for just this information.

I wanted to add this article for folks' information, which appears to describe the two common types of pipe insulation one sees: polyolefin (less expensive, like the water "noodles") and elastomeric (more expensive, often seen on A/C chiller lines). I won't repeat the info in it, because you might as well read it for yourself. It does a good job of comparing the two. Oddly, however, it doesn't offer much for either on heating (polyolefin may degrade at spike temps in a hot-water heating system and elastomeric hasn't been tested much).

http://www.enviro-tec.com/pdf/catalog/ccfInsulations-FromNIA.pdf

And maybe a better one I just found:

http://www.enviro-tec.com/pdf/catalog/WP-ClosedCellFoam.pdf


----------



## Gary in WA

Well, no one has mentioned that mice *love* to eat this on my pipes in the crawl space: http://www.lowes.com/lowes/lkn?action=productDetail&productId=24421-1410-LP10XB/6&lpage=none
It says- from -94*-------- +210*. Same brand, but mine is 10 years old, hope the new stuff is mouse-proof. 40% of it is on the ground with 3" oblong holes every 4-5" on 8-3' pieces. I'll use fiberglass tape over it next time.....
Be safe, Gary


----------



## ScottAlbrecht

Sorry for the delay. I was traveling but did finally get in touch with Nomaco. So here's the deal, Nolan's PE is *NOT* chemically cross-linked. Instead they attribute their higher temperature rating (to 210F) to using a superior resin.

So chemically is there a PEX version of pipe insulation foam? I don't know. One earlier responder suggests yes but I didn't find one. Chemically PEX and PE are all in the same family however.

Regarding which product to use, Nomaco suggests *their* PE is superior to their rubbber pipe insulation with regards to preventing condensation. Additionally for residental hot water supply lines which shouldn't exceed 140-150 F typically, you shouldn't have a problem with shrinkage on the hot water lines if "installed properly sealing all joints and connections with an approved sealing system". For those of you with lines toping over 200F, you probably need to consider rubber or something else if the temperature goes much higher as PE does fail quickly if you exceed its temperature rating for even a short duration. For cold water lines, it does seem like PE is the better choice at least the Nomaco PE since it should provide better protection against condensation which is the primary concern on cold lines...at least for me and I've decided to use Nomaco ArticFlex for my home's cold water lines. I haven't decided for the hot yet. In any case, the only other concern for using PE would be UV exposure. If using outdoors you do need to either encase or use rubber.

BTW, for some other poster, Nomaco has PE rated for use with heat tape.

Best of luck to everyone with their projects, a Merry Christmas, and wonderful New Year!


----------



## ScottAlbrecht

As a final comment. I wanted to thank all those for the great feedback on this forum. It was extremely helpful to me and very much appreciated!


----------



## bubbler

I'm dragging this thread up from the dead because it's the right time of year for many of us to think of it, but also because I wanted to re-ask a few questions--

I have a mix of 1-1/2", 1-1/4" and 1/2" black pipe (iron) for the first floor hot water system. The second floor uses 3/4" copper. My domestic hot water is provided by a coil in the boiler, it's 1/2" pipe.

Home Depot only seems to carry the cheap "PE Foam" in the sizes up to 1", so I bought various sizes of the PE foam to cover what pipes I could, and then fiberglass for the larger pipes.

My boiler aquastat keeps it at 180*-200*F, so water leaving the boiler could easily be 200* for the heating pipes. For the domestic hot water there is an adjustable mixing valve which is marked 120-160*, I keep it at about the middle, so I'd guess the temp of hot water will be at most 140* or so.

Will I have a problem using the cheap foam under these conditions? It's not being used on cold pipes, so condensation is not an issue.

The reason I'm questioning it because I see this PDF which lists the upper limit at 180*... I'm considering adjusting my aquastat to 160-180* to keep the pipe temps at or below 180*...


----------



## Alan

BobVilla said:


> The foam insulation is extremely flamable :furious:, so its not recommended to put foam insulation near your hot water heater (just to be safe)


That's kind of strange considering that water heaters come with two pieces of foam insulation.....


----------



## Alan

i wouldnt use cheap foam on boiler lines.


----------



## bubbler

Alan said:


> i wouldnt use cheap foam on boiler lines.


Do you say that because you believe it's inferior due to its price relative to other materials, or because you have some other knowledge of it?

I apologize if that comes across wrong, I appreciate all opinions, I'm just trying to figure out if this just your gut feeling, or because you know something about it. 

Also, I am using fiberglass pipe wrap on all the main first floor heating lines that are 1-1/4" and 1-1/2", because they are too large for foam. The exception being the 1/2" iron pipes that break off the main lines to feed the individual convectors. For the second floor it's 3/4" copper, they don't have any of the fiberglass that small, and in addition the pipe runs very tight to the joists, I can just barely get the foam slipped over it as is, FG would never work.

As for fire hazard... I'll be honest, I'm not that worried about that. Even assuming the boiler somehow malfunctioned and managed to heat up to say 240*, that is well below ignition point for anything, and if I have flames near this foam I have bigger problems.


----------



## bubbler

BTW, the reason to do this in my opinion is two-fold:

1) Reduce fuel use (get more heat to the baseboards/convectors and faster hot water to the taps). In addition to the pipe insulation, I'm learning more about my system, next summer I will definitely plan to lower the aquastat low/high limits. There was no reason to keep it set to 180/200*F this past summer, I could have easily gotten away with 150/170* for domestic hot water. 

2) Increase comfort ... if my convectors are averaging 140* w/o insulation, I might see 150* with, because there is nearly 150' of black pipe down there... on a cold day my cats press themselves against the basement door because the basement is actually staying warmer with all those pipes exposed then the first floor. I also have a ~30' run from my boiler to the bathroom taps and ~20' to the kitchen taps. By insulating those pipes I keep the slug of water in them hotter for a longer period, the result is potentially faster use of the water instead of waiting for a gallon or so of cold/warm water to flow before the hot stuff gets there.


----------



## Alan

Nothing to do with the price. Sometimes it gets knocked around under a house, and gets too close to a halogen light, and it basically disintegrates from the heat.

The cheap open cell foam insulation is not intended for high temp applications.


----------



## bubbler

Alan said:


> Nothing to do with the price. Sometimes it gets knocked around under a house, and gets too close to a halogen light, and it basically disintegrates from the heat.
> 
> The cheap open cell foam insulation is not intended for high temp applications.


It's a good point, but a halogen bulb is going to be at least 2-3X hotter than the boiler pipes (Halogen Bulbs, looks like 250*C to 600*C).

Looking again, I see they do have the fiberglass insulation for 1/2" and 3/4" pipes listed on their website, I must have missed it in the store. It's 8-9X more expensive per foot than the foam, but if it will be safer (for work lights, future torch plumbing repairs, etc) it's worth it.


----------



## MaintMan

Your forum popped up in response to my simple Google query, “what is the r value of pipe insulation”. I’m surprised that there seemed to be no mention or reference to the FTC’s R-Value Rule, http://www.ftc.gov/bcp/rulemaking/rvalue/index.shtml , the ASTM (American Society for Testing and Materials) International C680-10, http://www.astm.org/Standards/C680.htm , or even Wikipedia’s page, http://en.wikipedia.org/wiki/Pipe_insulation , where it states, “R-values of pipe insulation are not covered by the US FTC R-value rule”. Those interested in flammability issues might benefit from reading “Flammability of Plastics and Polymers…” (Paul A Kittle, Ph.D., April, 1993), www.aquafoam.com/papers/*flammability*.pdf . Having said all that, I found this helpful generalized site: “Insulating Your Hot Water Pipes…”. Having been in maintenance for over 25 years, I realize that there is a difference between the technical information that we should understand, and the simplified (kiss), condensed version that we must convey to management, customers, and personality-type A’s. It’s your decision.  -William


----------



## bubbler

MaintMan said:


> Having said all that, I found this helpful generalized site: “Insulating Your Hot Water Pipes…”.


Thanks MaintMan

I had seen that site before, it's a nice write up. It's what got me hunting around for thicker insulation types.

I have a few priorities as to insulating pipes:

1) Protect pipes in attic unconditioned space from freezing when not in use
2) Stop wasting heat (money) in places it doesn't belong
3) Keep heat in the pipes for faster DHW and heat at the convectors

For #1 I insulated the pipes in my attic space with those 2' fiberglass pipe insulators and wrap around foil-covered fiberglass for the areas that weren't straight pipes. I also draped and tucked the R13 FG batts being installed in my knee wall--the idea there to put the pipes inside the thermal envelope (even tho really, because FG is so air permeable, it won't work out very well). Ultimately I'd like to box in the pipes using 2x3's, plywood and FG, but that will have to wait until I have more time (Thanksgiving week).

For #2 & #3 I insulated my DHW pipes in the basement w/ the cheap R-2.2 foam and my heating pipes (also in basement) with a combination of both the 2' FG and the R-2.2 foam.

I haven't really noticed any difference in the speed that my DHW arrives at the bathroom taps. I also think that this effort to insulate heating pipes is going to literally be a drop in the savings bucket compared to the air sealing and other insulation work I'm doing.

The big push for me was really #1 ... last year when the house was vacant over the winter we left both heating zones set at 58*F. This year our usage model is very different, since we're living here we want the second floor to be warmer, but we don't necessarily want to run the central heat to produce the temperatures we want, so we're supplementing with a small electric radiator to keep the room up to the 68-70* we want. However, since the radiator and the central heat thermostat for 2nd floor are in the same room that means the 2nd floor central heat will probably not be kicking on much (if at all), that's why I'm now concerned about freezing pipes. I think a potential fix for this is to relocate the thermostat outside of our bedroom, that way the 2nd floor central heat can be set at ~62*F (or something low) and kick on/off as needed (keeping pipes warm), I just haven't done that yet.


----------



## JLinSC

Hi all. First time poster here. I found this thread while doing a Google search on the foam pipe insulation. I bought a house two years ago that was built in 2003. I'm in South Carolina and never thought I'd have frozen water pipes, but I've had that the last two winters. All of my water lines are PEX, and they run through the attic. The insulation in the attic is blown in fiberglass. None of the water pipes are insulated, and the contractor did a bad job with the blown in insulation. So my plan is to insulate all the water piping running through the attic, both hot and cold. I'm going to use the Armacell self-sealing foam insulation from Home Depot. I thought everything was going to be plain and simple, but then in this thread I'm reading about condensation on the cold water lines. Should I reconsider insulation the cold water lines? I planned on doing this next week but will now hold off until someone can give me a definitive answer about the cold water condensation. Thanks for any help!
While I'm insulating the pipes, I have to replace all the rafter vents and clean out the soffit vents. Gotta love contractors who could care less about quality....


----------



## nickv31

Hi everyone. I've read this entire thread as I'm in a similar situation as the OP. The twist is that my house was remodeled and the existing cast iron piping was re-piped with copper. With the house being built in the 50's, the cold and hot water pipe are run overhead in the attic. The plumber didn't bother insulating it or even recommending that we insulate our water pipe. So now when the temperature outdoors reaches 85 degrees +, and you turn on the cold water, a burst of scalding hot water will first be dispersed. This didn't make sense at first but after examining pipes and the lack of insulation, it makes perfect sense. As temperatures in the attic reach well over 125+ degrees on a hot day, it heats up the water that is in the copper pipes in the attic. 

I've read in this thread that some people recommend not insulating the cold water pipe unless freezing is a problem.  In this case, I would have to insulate the cold water pipe with the self sealing PE pipe insulation. With it being 100% closed cell, would I need to worry about any possible condensation? Would anyone recommend also insulating the hot water pipe with the self sealing PE pipe insulation to help with heat loss in the early hours of the morning after a cold night? And any recommendations for taping the joints as well?

Last part. Even if I manage to insulate most of the pipe in the attic (some will be darn near impossible given the pitch of my roof and where the pipe runs to exterior wall cavities... There is still a chance that the copper lines that are in exterior wall cavities will heat up on a hot day right? So is there another alternative to insulating the pipe overhead?

Thank you for the help in advance.


----------



## bubbler

nickv31 said:


> I would have to insulate the cold water pipe with the self sealing PE pipe insulation. With it being 100% closed cell, would I need to worry about any possible condensation?


I think condensation will be more of an issue in a hot/humid attic with the pipe exposed to all of the air mass. I think you'll have less condensation if you have a tight fitting foam rubber insulation against the pipes because there will be less humid air circulating around it--No humid air, no condensation.

Insulating the hot water would make sense if the attic ever gets cold, such as overnight when you want early morning showers.

For my exposed attic heating pipes I used Aramcell foam insulation, it had tape on either side of the split so that it would seal together. I then over-wrapped on the straight sections with paper-backed fiberglass pipe insulation (which had an integrated adhesive tape flap for sealing. For bends I used a paper backed fiberglass wrap and some foil tape.

I wrapped a thermocouple against the pipes to monitor the temperature and found that even when the outside air was in single digits, and the attic air was in the 20s (F), the pipes would never drop below much below high 50s (F) even if the heat zone had been inactive for several hours--as in, the heat from the interior space of the house would heat the pipes before/after the attic entry and that would bleed back keeping them at reasonable temperatures. For my purposes that was a success because my concern was frozen heating pipes in the winter.

Even if you can't insulate every inch of your copper pipes I would guess that insulating as much as you can would be a help in preventing transfer of the ~125F attic temps to your copper pipes, and will reduce the amount of condensation dripping down on to your existing insulation.

Creative use of spray foam insulation can also help to insulate from the higher attic temps in the tighter areas.

As an alternative--if the pipes are tight to, or at least close to, the joists you could also build boxes out of 1" rigid insulation and try to move the pipes into the conditioned space of your house vs. the unconditioned attic.


----------



## nickv31

Thank you bubbler! Very useful information. I will measure out the pipe sizes and count the number of T's and elbows I will need to start insulating this weekend.


----------



## SPS-1

Keep us posted how it works out, but I am concerned that 1" of insulation around the pipes is just going to have it take 4 hours to get the water in the pipe to 125 rather than 2 hours. Just guessing on the numbers, but you get my point. Bublers last paragraph of making the pipe area part of the conditioned space has a lot of merit, but may be more difficult.


----------



## mebgardner

Hello all, and thank you for this informative thread. I see I am again ressurecting an older, dormant thread.

I too came to this thread to learn about water pipe insulation.

I have a different system to apply these ideas, a completely exterior system. 

I am attempting to understand how to perform a transition of a below ground run of PEX-A to above ground riser transition, ending in a courtyard hose bib, attached to a south facing (sunny) concrete wall, in Tucson AZ.

A short backstory: A few years ago, Tucson experienced a "hard freeze" over 4 days. Many exterior pipes burst. I would like to avoid that outcome.

My concerns are for avoiding bursting due to freezing, and longevity due to UV exposure. I know about how I should shut off this exterior line during freeze conditions, and / or dribble water from the bib. No need to go there. Let's just say the line needs to remain active, and I accept that risk.

I have seen "you-tube" video of a S.C. plumbing professional bringing PEX-A above ground and covering the above ground connection with split foam tubes, (not possible to say what kind of foam used). The video thread states he did this to mitigate the UV concerns.

So what do you folks think? Bring the PEX-A out and above ground for the "best" anti-freeze burst performance, over as much above ground exposure as possible, or type L copper as the above ground to below frost line transition, for its longevity in UV conditions?

Either method selected will likely be covered in some type foam product, and then wrapped with HVAC type metal tape (The UV and Insulation performance over a hopefully long service life, are the concerns I have in view).


----------



## bubbler

mebgardner said:


> Either method selected will likely be covered in some type foam product, and then wrapped with HVAC type metal tape (The UV and Insulation performance over a hopefully long service life, are the concerns I have in view).


I think I'd use heat tape on a 40F switch under foam insulation and wrap that in something UV resistant (could use a sliced PVC pipe to wrap around it).

The heat tape is what will save you from bursting for those couple of days every few years that you have a hard freeze.


----------



## mebgardner

Thanks Bubbler, for the kind reply. 

I sense I should add some information. The project is a re-plumb of an existing buried 1/2" poly-butelene line with a galvanized riser above ground.. This line is approx. 20 years old, and never a problem, never burst (I attribute to sunny exposure).

The other thing I believe important is, the line runs to a remote courtyard some 80 ft. distant, with no easy electric service.

Why replace a working, no problem line? Not important, its being replaced. Please continue, thanks.


----------



## mebgardner

I can also now add to the knowledge store.

I've had some back 'n forth with an Uponor tech rep., and learned a few things about transitioning PEX-A to above ground. (Wirsbo is also in view, same stuff, may be re-branded Uponor).

So, I have been told by them that: a) Direct contact with tape, or _any_, adhesive, is no fly. That included strip type self closing split foam insulation. Do not allow the adhesive to contact their pipe. No direct contact with Adhesive.

And b) They are OK with bringing their PEX-A pipe above ground if it is wrapped in insulation foam, to mitigate UV. I enquired about also taping that foam up with metal tape, and they said OK with the understanding about no direct contact with adhesive.

So, I still have these two choices: Foam and metal HVAC tape protected PEX-A, or foam and HVAC tape protected type L copper?

Which would you choose? Why?


----------



## Engineer Duane

Mebegardener. Greetings from Canada where we bury waterlines 8 feet below grade to prevent freezing. 

Fire hydrants work in very cold weather. They do so by putting the valve in the ground below the frost line and having a dry stand pipe that has nothing to freeze where temperatures get cold. You can get smaller buried frost protected valves for this purpose.

Generally in Canada we have non freeze hose bibs that put the valve 8-12 inches behind the spigot and make sure the spigot is located in a heated building. Doesn't help you.

Pex will withstand freezing a lot better than copper pipe if you are unfortunate to freeze it. 

In my garage I have a sawn off golf club bolted to a ball valve in the heated part of the house to provide water to an unheated area when needed. It's overhead so it naturally drains when the valve is closed above it.

I have also seen foam "boobs" that can be strapped over taps when not in use to add a little time constant to your freeze countdown.

Use black paint or coverings. Solar warming is much better using black.

I am going to put a recirc loop on a outdoor piping arrangement (hottub heating) with a temperature sensor to flow the line prior to freeze up. 

What initially attracted me to this thread was rubber vs foam insulation for pex freeze protection in -40c. I picked the expensive rubber because the birds eat the pe on my trampoline but seem to leave my ac lines with rubber insulation alone.


----------

