Forums | Home Repair | Home Improvement | Painting | Interior Decorating | Remodeling | Landscaping


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-14-2011, 03:48 PM   #16
Member
 
Join Date: Jun 2006
Posts: 65
Share |
Default

insulating pex pipes


The only reason to secure PEX is to keep it from moving around and to keep it organized. Laying on concrete I could see it over time possibly chafing and ultimately failing because it is going to move around as a result of the water traveling through it and expansion/contraction. Movement would be especially prevalent where it changes direction.

What you might consider is laying down some 2x6 or 2x8 on the concrete depending on the number of lines you're running and securing the tubing to them every couple of feet, again paying particular attention to securing at changes in direction.
BOUTYM is offline   Reply With Quote
Old 10-16-2011, 07:02 AM   #17
Newbie
 
Join Date: Oct 2011
Posts: 2
Default

insulating pex pipes


Hi. A little off topic and perhaps a bit basic...

I found this thread via Google. I'm frustrated with my new home and how bloody long it takes to get hot water to any of my taps. The single hot water tank is very central and it doesn't appear that any of the runs are that long - unless they've taken extremely inefficient runs to get there. House is mostly finished but there are some exposed pipes in the mechanical room/closet where the HWT is as well as one unfinished room that at least some of the pipes go through. Those areas themselves are indoor spaces and are not cold.

My question: Can I expect any benefit at all from adding pipe insulation to the few feet of exposed pipe that I can see? I'm not interested in tearing down drywall to add more.

Thanks.

- Steven
s_mack is offline   Reply With Quote
Old 10-16-2011, 07:47 AM   #18
Member
 
Join Date: Jun 2006
Posts: 65
Default

insulating pex pipes


Quote:
Originally Posted by s_mack View Post
Hi. A little off topic and perhaps a bit basic...

I found this thread via Google. I'm frustrated with my new home and how bloody long it takes to get hot water to any of my taps. The single hot water tank is very central and it doesn't appear that any of the runs are that long - unless they've taken extremely inefficient runs to get there. House is mostly finished but there are some exposed pipes in the mechanical room/closet where the HWT is as well as one unfinished room that at least some of the pipes go through. Those areas themselves are indoor spaces and are not cold.

My question: Can I expect any benefit at all from adding pipe insulation to the few feet of exposed pipe that I can see? I'm not interested in tearing down drywall to add more.

Thanks.

- Steven
What's a 'few' feet? If you are literally talking a few feet it's probably not going to do much to insulation that with the exception that the insulation would help prevent condensation on the cold water pipe if humid air got to it, but I think there may be more to this.

When you say it takes a long time, how long are you talking? How hot is the water when it finally gets to the faucet? What is the temp set at on the water heater? Even though the heater is centrally located, how far is it from the faucets? What diameter pipe was used? Does the piping run from the heater below the floor and up to the fixtures? Are you building the house, or is it being built? Is insulation required in your area by code? Quite a few things figure into this.
BOUTYM is offline   Reply With Quote
Old 10-16-2011, 09:08 AM   #19
Newbie
 
Join Date: Oct 2011
Posts: 2
Default

insulating pex pipes


Thanks for your reply. I don't have all the answers, but here are a few:
  • The house is already built and finished. I didn't build it... I just bought it.
  • The O.D. appears to be slightly larger than 3/4". No idea what the I.D. is.
  • A "few feet" isn't literally a few. All told, its about 26' but that's accounting for several runs or "branches" (sorry, I'm not a plumber and don't know the correct terms) to the various fixtures. As a general estimate, I'd figure its about 15% to 20% (give or take) of each run.
  • The kitchen sink is the one that annoys me the most because I use it to the most... it takes about 30 seconds to run hot. OK, that may not sound like a lot, but that's a lot of wasted water and I've never had a home take that long (although this is by far the largest home I've ever lived in). That's not the longest though... the main bathroom sink takes about 45 seconds and its probably the CLOSEST (in terms of physical straight line distance) to the tank.
  • When the hot water finally gets there... it is hot. I haven't taken a temperature, but it is sufficiently hot that you wouldn't want your hand in it for more than a couple of seconds.
  • I don't know what the tank is set to. I had a guy come and look at it and he turned it up arbitrarily to see if that helped... it didn't. The water is hotter now, but that wasn't the problem.
  • Physical straight line distance to the kitchen sink... it is 28 feet, but one floor up. However I have no idea at all what path it actually takes. The main bathroom is directly above the tank and that one takes the longest to heat up.
  • Yes, the tank is on the lower floor and it runs up to the fixtures above. Even for the lower floor fixtures, it appears the lines run up to the ceiling and over. They're no faster.
  • Is insulation required by our code? I imagine not. These are new homes... I would assume they meet code (but maybe that's asking too much).
I've considered a recirculating pump, but I really don't like the idea of the extra electricity and gas required to keep that going. But I also don't like wasting all the water while I wait for it to heat up! Plus I imagine I'm wasting gas anyway heating the water that goes into the pipes only to have them cool down.

- Steven
s_mack is offline   Reply With Quote
Old 10-16-2011, 10:29 AM   #20
Household Handyman
 
Join Date: Feb 2009
Location: Albany, Ga.
Posts: 2,231
Default

insulating pex pipes


Having worked with PEX for some time now, I would not recommend just "laying" PEX on any substance. I firmly believe that just laying PEX on any surface will lead to a hole being rubbed into the PEX in due time. Notice how the pictures in your house seem to become slightly crooked over time? This is due to gravitational pull and I firmly believe the same effect will cause PEX to move slightly if just laid on some surface.
Thurman is offline   Reply With Quote
Old 10-16-2011, 11:08 AM   #21
Member
 
AlbacoreShuffle's Avatar
 
Join Date: Sep 2011
Posts: 131
Default

insulating pex pipes


Quote:
Originally Posted by s_mack View Post
Thanks for your reply. I don't have all the answers, but here are a few:
  • The house is already built and finished. I didn't build it... I just bought it.
  • The O.D. appears to be slightly larger than 3/4". No idea what the I.D. is.
  • A "few feet" isn't literally a few. All told, its about 26' but that's accounting for several runs or "branches" (sorry, I'm not a plumber and don't know the correct terms) to the various fixtures. As a general estimate, I'd figure its about 15% to 20% (give or take) of each run.
  • The kitchen sink is the one that annoys me the most because I use it to the most... it takes about 30 seconds to run hot. OK, that may not sound like a lot, but that's a lot of wasted water and I've never had a home take that long (although this is by far the largest home I've ever lived in). That's not the longest though... the main bathroom sink takes about 45 seconds and its probably the CLOSEST (in terms of physical straight line distance) to the tank.
  • When the hot water finally gets there... it is hot. I haven't taken a temperature, but it is sufficiently hot that you wouldn't want your hand in it for more than a couple of seconds.
  • I don't know what the tank is set to. I had a guy come and look at it and he turned it up arbitrarily to see if that helped... it didn't. The water is hotter now, but that wasn't the problem.
  • Physical straight line distance to the kitchen sink... it is 28 feet, but one floor up. However I have no idea at all what path it actually takes. The main bathroom is directly above the tank and that one takes the longest to heat up.
  • Yes, the tank is on the lower floor and it runs up to the fixtures above. Even for the lower floor fixtures, it appears the lines run up to the ceiling and over. They're no faster.
  • Is insulation required by our code? I imagine not. These are new homes... I would assume they meet code (but maybe that's asking too much).
I've considered a recirculating pump, but I really don't like the idea of the extra electricity and gas required to keep that going. But I also don't like wasting all the water while I wait for it to heat up! Plus I imagine I'm wasting gas anyway heating the water that goes into the pipes only to have them cool down.

- Steven
I would install a Grundfo Comfort system.
They are very easy to install, and wont set you back to much $$$$

http://www.google.com/products/catal...ed=0CF0Q8wIwAA#
Attached Images
 
AlbacoreShuffle is offline   Reply With Quote
Old 10-16-2011, 11:08 AM   #22
Civil Engineer
 
Join Date: Mar 2009
Location: Boston
Posts: 3,968
Default

insulating pex pipes


PEX moves very slightly if it is not secured. This has nothing to do with gravitational pull, which is downward, and cannot exert a lateral force on the pipe. The effect is due to temperature changes, which are particularly apparent on the hot water pipe, as the water in the pipe cools slowly if the water is not run, then heats up when a hot water tap is opened. PEX expands and contracts slightly with temperature change, leading to movement of the pipe.

The pipe also moves slightly due to forces exerted by flowing water around bends. There are loads exerted at bends when the water is flowing that must be resisted by the pipe itself if the pipe is not connected to the floor, and this leads to movement of the pipe as the water is turned on and off.

The movement is small, and if the pipe is not connected to the surface, there is little vertical load on the pipe, hence little friction. My guess is you could go 50 years without rubbing a hole in the pipe, however if the concrete is rough, and you want to protect the pipe, you can lay the pipe over a smooth surface like nylon or vinyl, a simple roll of 6 mil polyethylene would be fine. Then when the pipe moves, you will not wear out the pipe at all.
Daniel Holzman is offline   Reply With Quote
The Following User Says Thank You to Daniel Holzman For This Useful Post:
bobsmithhome (03-30-2012)
Old 10-17-2011, 06:28 AM   #23
Member
 
Join Date: Jun 2006
Posts: 65
Default

insulating pex pipes


I've never really considered it until reading this thread, but is there any info or does someone know how much of a difference there is in heat loss with PEX vs. copper?
BOUTYM is offline   Reply With Quote
Old 11-27-2011, 05:37 PM   #24
Newbie
 
Join Date: Dec 2008
Posts: 4
Default

insulating pex pipes


I'd rethink putting in that Grundfos system unless you don't have a problem with extra load on your water heater when cold water is used. Look up "hot water siphoning+hot water circulator". Saved me from cold water waiting and high gas bills.

I think there would be greater heat loss with copper since the metal absorbs heat quickly and it would allow heat to transfer to the outside surface of the pipe quicker.
DIY4WIFE is offline   Reply With Quote
Old 03-28-2012, 03:15 PM   #25
Member
 
Join Date: Mar 2012
Location: Massachusetts
Posts: 221
Default

insulating pex pipes


Quote:
Originally Posted by Jim the plumber View Post
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.
Getting back on topic.
As mentioned PEX pipe moves around if not secured and can eventually wear through. Why don't you kill two birds with one stone and insulate the pipe with the foam pipe before you place it over the concrete. This will give you an extra thick wear layer. I would probably wrap it in duct tape (cheap solution) or run it through the corrugated pipe used for underground PEX to give it a little more protection.
You probably should get your plumbing inspectors opinion on this.
goosebarry is offline   Reply With Quote
Old 03-28-2012, 03:23 PM   #26
Member
 
Join Date: Mar 2012
Location: Massachusetts
Posts: 221
Default

insulating pex pipes


I plan on insulating a 30 foot straight run of PEX pipe running through the basement perpendicular to the joists. If I mount the pipe to the joist using talons or clips before I insulate the pipe, I'll have to notch around all the joists. So I was thinking of insulating the pipe first, but now I need some oversized hangers to hang the insulated pipe.

Does anyone have any suggestions?
goosebarry is offline   Reply With Quote
Old 03-28-2012, 04:10 PM   #27
Member
 
Homerepairguy's Avatar
 
Join Date: Aug 2010
Posts: 735
Default

insulating pex pipes


Quote:
Originally Posted by Jim the plumber View Post
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.
Jim,

Can you push PVC pipe over the concrete beams? If so, you could install PVC pipes larger than the PEX lines and then push or pull the PEX lines through them. This would solve the distance between clamps and the abrasion problems.

If you do this, I recommend installing a 360 degree loop in the PEX lines at both ends, but if not possible, at least at one end. The loop will allow the PEX to expand and contract properly. It is especially imperative that the 360 degree loops at the ends be installed for the hot water line. PEX hot water lines expand and contract quite a bit and installed in PVC pipes, there will not be the droop between hangers to help absorb that movement.

I would install one 360 degree loop at one end for cold water lines and two 360 degree loops at both ends for hot water lines (though one larger 360 degree loop for a hot water line could work too).

HRG

Last edited by Homerepairguy; 03-28-2012 at 04:14 PM.
Homerepairguy is offline   Reply With Quote
Old 03-28-2012, 09:49 PM   #28
Member
 
Join Date: Aug 2010
Posts: 1,526
Default

insulating pex pipes


Quote:
Originally Posted by goosebarry View Post
I plan on insulating a 30 foot straight run of PEX pipe running through the basement perpendicular to the joists. If I mount the pipe to the joist using talons or clips before I insulate the pipe, I'll have to notch around all the joists. So I was thinking of insulating the pipe first, but now I need some oversized hangers to hang the insulated pipe.

Does anyone have any suggestions?
I use EMT 2 hole clamps. They work great over insulated pipe.

VIPlumber is offline   Reply With Quote
The Following User Says Thank You to VIPlumber For This Useful Post:
goosebarry (03-29-2012)
Old 03-29-2012, 03:59 PM   #29
Member
 
Join Date: Mar 2012
Location: Massachusetts
Posts: 221
Default

insulating pex pipes


The 2" 2 hole EMT clamp is perfect. The local store had 2" 1 hole EMT and 2" 2 hole PVC. The pipe with insulation is a little loose in the PVC clamp. The EMT clamp can be deformed a little to better hold the insulation. One screw hole isn't secure enough around this klutz. I could see me pulling down 50 feet of pipe. I need 2 holes.

Thank you
goosebarry is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Drain Pipes, Walls and Studs mattaparity Plumbing 2 12-18-2011 07:22 AM
Knocking Copper Hot Water Pipes in Winter desron1964 Plumbing 5 11-19-2009 10:24 AM
Water Heater 1/2 inch pipes tke402 Plumbing 7 10-04-2008 11:19 AM
Installation of new pipes on Water main... NJE Plumbing 3 02-05-2007 12:06 PM
Is it normal to see green stuff on the supply pipes KUIPORNG Plumbing 2 06-30-2006 11:21 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.