DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Plumbing (http://www.diychatroom.com/f7/)
-   -   insulating pex pipes (http://www.diychatroom.com/f7/insulating-pex-pipes-13494/)

ibs325 11-16-2007 09:55 PM

insulating pex pipes
 
Hi,
Just installed new water heating system at home. Plumber who install radiators told me that i must insulate pex pipes in crawling space for heat loss reasons. This crawling space not cold in a winter time (about 50 F), but he told me i Must do it right with the fiberglass insulation (cost $6 for 6') , not with polyethylene foam pipe insulation ( cost $1 for 6' at HD). Guy who install boiler (25 years in heating business) told me polyethylene foam pipe insulation is OK and he use it all the time. I need to insulate 300' of the pex pipes and the price difference is hi! For whom I have to Trust?

Thank you very much for your advices!

That one Guy 11-16-2007 10:55 PM

He is correct about the heat loss. It happens here in the winter with copper pipe sometimes. It may not be always a noticable loss though. You should be fine with the foam pipe insulation. Cut the ends acordingly and tape them for an air tight seal. Fiberglass is great on some stuff but kinda old school.

kcrossley2 11-17-2007 02:37 AM

I'm interested in doing this too. Where's the best (most affordable) place online to buy foam pipe insulation?

BobVilla 10-15-2008 01:21 PM

Quote:

Originally Posted by kcrossley2 (Post 74433)
I'm interested in doing this too. Where's the best (most affordable) place online to buy foam pipe insulation?

The best place I know online for pipe insulation is

tstorzuk 02-10-2010 10:51 AM

You must NOT use polyethylene foam pipe insulation. It creats a reaction between the PEX and the insulation that degrades the PEX pipe.

Check with manufacturer of the PEX that you purchased. Some grades are able to be insulated with polyethylene foam pipe insulation. Most are not.

Alan 02-10-2010 11:03 AM

Where's the documentation against using this type of insulation? Can you provide a link ? I'd really like to see it just for my own reference.

To the OP : The only problem I have with insulating pex is that you can't insulate the fittings very easily. That 1/2" insulation you get for the pipe won't go over the expanded joints. This might be different if you use the crimp rings instead, but I always hate insulating our pex jobs. :furious::censored:

tstorzuk 02-10-2010 11:51 AM

Alan,

I've been looking for that for a while this morning and I can't seem to find it.

If I recall correctly, it's in one of the following ASTM codes;

F876, F877, F1281, or F1960

Or it's on the manufacturer's web sites.

I can't find my copies of the ASTM codes, and therefore can't tell you exactly which one it's in. But I do remember it having to deal with the type of PEX pipe that is used. There are a few different ones;

PE-Xa, PE-Xb and PE-Xc.

I do not believe it was relevant to the PEX/Aluminum/Pex sandwich manufacturing method, as the aluminum acts like an insulating barrier already, and the reaction would probably be stopped by the aluminum and not carry though to the inner layer.

If you want to be sure, contact the manufacturer of the PEX that you have installed. That is what I did, and they told me NOT to use the polyethylene foam pipe insulation. Instead, I ran the PEX up in floor joists so that I could use standard fiberglass insulation in the areas where it ran.

I'm sorry, but if you're concerned about running $6 worth of materials as opposed to $1, I guess you're just worried about making a buck and turning the house to sale. If it's your home, then spend the extra $5, be sure about the safety of your piping system and sleep soundly.

Alan 02-10-2010 12:00 PM

Quote:

Originally Posted by tstorzuk (Post 397597)
Alan,

I've been looking for that for a while this morning and I can't seem to find it.

If I recall correctly, it's in one of the following ASTM codes;

F876, F877, F1281, or F1960

Or it's on the manufacturer's web sites.

I can't find my copies of the ASTM codes, and therefore can't tell you exactly which one it's in. But I do remember it having to deal with the type of PEX pipe that is used. There are a few different ones;

PE-Xa, PE-Xb and PE-Xc.

I do not believe it was relevant to the PEX/Aluminum/Pex sandwich manufacturing method, as the aluminum acts like an insulating barrier already, and the reaction would probably be stopped by the aluminum and not carry though to the inner layer.

If you want to be sure, contact the manufacturer of the PEX that you have installed. That is what I did, and they told me NOT to use the polyethylene foam pipe insulation. Instead, I ran the PEX up in floor joists so that I could use standard fiberglass insulation in the areas where it ran.

I'm sorry, but if you're concerned about running $6 worth of materials as opposed to $1, I guess you're just worried about making a buck and turning the house to sale. If it's your home, then spend the extra $5, be sure about the safety of your piping system and sleep soundly.

If you come across it in the future would you mind PMing it to me? I'd love to see it just for my own peace of mind

tstorzuk 02-10-2010 12:03 PM

Alan,

I certainly will.

Right now I am in the process of emailing manufacturers to find out which ones shouldn't be insulated with that type. I've also asked for documentation, so I'll send it along and post it here when I get any replies.

Rory Read 02-10-2010 12:40 PM

insulating pex
 
I insulate any pipe in an unconditioned space because I don't want it to freeze. I separately insulate hot water supply lines in conditioned spaces because I want to use less energy and deliver hotter water to the plumbing fixture or radiant loop.

I have always used foam pipe wraps on Pex. I would be worried after reading this thread but for the fact that all my plumbers insulate it the same way. (I think it might just be some cpvc that you don't want to wrap with foam insulation sleeves, but that's a just a foggy and probably inaccurate memory. And by the way, if there is a problem with wrapping pex pipe with foam sleeves, I need to know too, although I really don't want to know.)

I insulate crawlspaces for all the reasons I insulate any other building exterior, and the why, how, and how much $ varies a bit case to case.

Thanks,

Rory

RDG Read Development LLC
Portland, OR

tstorzuk 02-10-2010 03:52 PM

1 Attachment(s)
So what I have now found is contradictory to what was previously available. Attached is a service bulletin from one manufacturer that states the same. Also, an email that I have just received from a different manufacturer below;

Hello tstorzuk,

Our Tubolit Polyethylene Pipe Insulation and AP Armaflex tubes do not have any adverse effects on any plumbing piping. At times, questions have been asked concerning our Armaflex 520 adhesive. 520 is a solvent based adhesive for sealing joints on the insulation. The 520 adhesive is also safe to use with PEX tubing. Armacell has performed numerous tests and our products are safe and recommended to use with PEX.

I believe the temperature limitations for PEX is 180 degrees F. We recommend our Tubolit Polyethylene Pipe Insulation also to 180 F. With a maximum temperature of 200 F. Polyethylene Pipe Insulation can melt if subjected to temperatures over 207 F.

Thank you,
Bob Dizel
Armacell LLC
Sales & Marketing Manager, NorthEast

Daniel Holzman 02-10-2010 06:09 PM

I cannot understand the chemistry behind a claim that polyethylene tubing (PEX) would react negatively with polyethylene foam insulation. Both products are made of polymerized ethylene (polyethylene). Polyethylene is well known for its chemical inertness, i.e. it is very difficult to get anything to bond to polyethylene because of the difficulty in achieving surface activation of the material. I cannot understand how polyethylene foam insulation could possibly react with PEX pipe, I too would be very interested in the documentation for this claim, and by the way my PEX pipe at home is insulated with polyethylene foam and if there is some history of trouble I certainly would like to know about it.

kcrossley2 02-11-2010 02:57 AM

If anyone decides to insulate their PEX, please post a few photos and a link to the product you used. Thanks!

vernon h 03-30-2011 05:08 PM

I just ran pex in my attic insulated in the poly insulation. I just wonder to what temp it would protect it from freezing

Jim the plumber 05-16-2011 06:16 PM

I was fixin to run pex under my house, there is no room to crawl under this house. It was built in the 20's and there is only about 5 or 6 inches of crawl space. there is concrete beams running 4' apart the length of the house with the floor joist resting on them. The crawl space is the space above the concrete beams and the floor so I cant dig.. I was going to run the pex across the beams, now I've read that pex needs to be clamped to a floor joist every couple of feet and theres no way I can do that. My plan was to just let it lay on the concrete beams. I was also going to use the polyethylene foam pipe insulation. I'm not really a plumber but I'm becoming one because no plumber here will touch this old house unless it's something inside, I live in Diamond back country and they're almost thicker than flies here.. Is there a reason I can't go ahead and let the pex lay on the beams without support, thats the way the galvanized pipe was installed that the pex will replace.


All times are GMT -5. The time now is 08:36 AM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved