Pex

[Zorba]

It looks like the terminology we're looking for is "sleeving":

http://www.inspectionnews.net/home_...-water-main-into-polyvinyl-chloride-pipe.html

This post in particular:



Cheap insurance for sure. Plus easy maintenance & upgrades down the road!

The quote doesn't make it sound like it was water tight sleeve though. Putting a PVC conduit under driveways and sidewalks is very common, but I've never seen one that was water tight, just provided a sleeve to run piping through.

 

[Kaido]

The quote doesn't make it sound like it was water tight sleeve though. Putting a PVC conduit under driveways and sidewalks is very common, but I've never seen one that was water tight, just provided a sleeve to run piping through.

I think that would depend on how you set it up. I've never heard of anyone doing it either, though. But my experience with Sharkbite was good - my buddy gave me a few minutes of training & we got it setup in no time. I'd love to have that kind of functionality in a future home, especially with the added benefit of having a place for the water to actually go if any given PEX pipe does burst.

 

[waffleironhead]

Frankly I think some of that is marketing bunk. I don't buy the reduced flow, where a you have to use an elbow for cpvc, you can use a bend support on pex. a 6" radius continuous piece of pipe is going to flow a heck of a lot more than a 90. Not to mention being able to use a manifold system on pex. That will greatly reduce the time for hot water to get to the fixtures

It could be just the brand, but i've done repairs on 30 year old cpvc. The stuff is brittle. I try to cut it out with my ratcheting cutter and it just shatters. I was trying to cut out a piece that froze and went back 3-4" from where it broke. Not only did it not cut cleanly, but a hairline crack shot back 6" further into the pipe. Don't know if it's the age or poor quality pipe, but i've run into it a half dozen times on my rentals.

I don't think there is any perfect solution. Each system has some disadvantages.

The reduced flow claim comes from the fact that most pex fittings go inside the tubing. Thus your flow diameter is reduced at each fitting. Whereas cpvc fittings are placed outside of the pipe, not affecting the flow.

 

[Greenman]

I think that would depend on how you set it up. I've never heard of anyone doing it either, though. But my experience with Sharkbite was good - my buddy gave me a few minutes of training & we got it setup in no time. I'd love to have that kind of functionality in a future home, especially with the added benefit of having a place for the water to actually go if any given PEX pipe does burst.

In 28 years as a general contractor, I've seen one house badly trashed by a blown pipe, and another one get about $4k worth damage. Fire is far more likely, far more dangerous, and far more destructive. Also, putting area drains in your kitchen and bathrooms, then sloping the floor towards them, will make them look like gas station bathrooms.
Rather than trying to re-invent watter supply plumbing, I'd spend the money on quality material and labor, and maybe better insurance.

 

[Zorba]

In 28 years as a general contractor, I've seen one house badly trashed by a blown pipe, and another one get about $4k worth damage. Fire is far more likely, far more dangerous, and far more destructive. Also, putting area drains in your kitchen and bathrooms, then sloping the floor towards them, will make them look like gas station bathrooms.
Rather than trying to re-invent watter supply plumbing, I'd spend the money on quality material and labor, and maybe better insurance.

Also the cheap insurance of turning off your water supply at the meter anytime you are going to be away for an extended period of time.

 

[pcgeek11]

Frankly I think some of that is marketing bunk. I don't buy the reduced flow, where a you have to use an elbow for cpvc, you can use a bend support on pex. a 6" radius continuous piece of pipe is going to flow a heck of a lot more than a 90. Not to mention being able to use a manifold system on pex. That will greatly reduce the time for hot water to get to the fixtures

It could be just the brand, but i've done repairs on 30 year old cpvc. The stuff is brittle. I try to cut it out with my ratcheting cutter and it just shatters. I was trying to cut out a piece that froze and went back 3-4" from where it broke. Not only did it not cut cleanly, but a hairline crack shot back 6" further into the pipe. Don't know if it's the age or poor quality pipe, but i've run into it a half dozen times on my rentals.

I don't think there is any perfect solution. Each system has some disadvantages.

That must have been some crappy pipe, IMO. Or the pipe was used in a way that was not normal.

From actual studies: http://www.ppfahome.org/faq.aspx

Does PVC pipe have a long life expectancy?

Yes, studies on PVC pipe made in Europe in the 1930’s and been in continuous use suggest a very long useful life for these products of a hundred years or more, which will generally exceed the lifespan of the structures they are installed in.

What is the expected performance of a CPVC water distribution system?

CPVC piping systems have been installed and operated since 1959, and initial installations are still performing faultlessly. CPVC piping will not fail prematurely due to corrosion, electrolysis, or scale build-up in areas where water, soil, and/or atmospheric conditions are aggressive.

 

[pcgeek11]

Also the cheap insurance of turning off your water supply at the meter anytime you are going to be away for an extended period of time.

I always do this when leaving for an overnight trip or greater.

 

[Kaido]

In 28 years as a general contractor, I've seen one house badly trashed by a blown pipe, and another one get about $4k worth damage. Fire is far more likely, far more dangerous, and far more destructive. Also, putting area drains in your kitchen and bathrooms, then sloping the floor towards them, will make them look like gas station bathrooms.
Rather than trying to re-invent watter supply plumbing, I'd spend the money on quality material and labor, and maybe better insurance.

Yeah, that's one of my concerns - ugly sloped floors :biggrin:

Another concern is that different states are starting to make residential fire sprinklers mandatory, which I think is a good thing:

http://www.firesprinklerinitiative.org/legislation/sprinkler-requirements-by-state.aspx

But it seems like that pretty much doubles your chances of springing a leak, since you now have more pipes running in your ceiling or wherever.

Anyway, it seems pretty dumb to risk a leak, ever, if all you have to do is put it inside another pipe for drainage. To skip the in-floor drains, doing a combination of CVPC sleeving for PEX & a water-leak detector with auto-shutoff valve seems like a good combination, so even if you did spring a leak, it would funnel into the room (or say cabinet under the sink), get detected by the sensor (hopefully), and then shutoff the water line.

Although I'm not a big fan of active solutions - I like passive solutions a lot more since there's no risk if the active solution fails. But then you have to deal with weird stuff like sloped floors & in-floor drains. Can't win :biggrin:

 

[Kaido]

In 28 years as a general contractor, I've seen one house badly trashed by a blown pipe, and another one get about $4k worth damage. Fire is far more likely, far more dangerous, and far more destructive. Also, putting area drains in your kitchen and bathrooms, then sloping the floor towards them, will make them look like gas station bathrooms.
Rather than trying to re-invent watter supply plumbing, I'd spend the money on quality material and labor, and maybe better insurance.

Actually one small story, I'm currently in a slim 2-story condo. The master bathroom on the 2nd floor developed a slow leak in a pipe that went through the ceiling of the living room underneath. It was a very slow leak that caused layers of damage over time, which we finally noticed when the popcorn ceiling started staining (no sign of damage in the bathroom itself). Ripped it all out & it was a total nightmare to repair, everything was rotted & nasty. A simple CPVC conduit for the pipe would have completely removed that issue, along with say a water leak detector at the end of the pipe for drip detection.

Seems like a dumb thing not to do for something that can have such horrible consequences down the road...it's basically hardware insurance. But I guess when you factor in the material cost, labor cost, and fact that it rarely happens, most people aren't really too keen on making the investment, which makes economic sense, especially if you do have good insurance.

 

[drnickriviera]

I just did a search for 'brittle cpvc' doesn't look like i'm the only one that has noticed it. Lots of people calling cpvc junk. One even said 3 yr old flowguard was becoming brittle

That must have been some crappy pipe, IMO. Or the pipe was used in a way that was not normal.

From actual studies: http://www.ppfahome.org/faq.aspx

Does PVC pipe have a long life expectancy?

Yes, studies on PVC pipe made in Europe in the 1930’s and been in continuous use suggest a very long useful life for these products of a hundred years or more, which will generally exceed the lifespan of the structures they are installed in.

What is the expected performance of a CPVC water distribution system?

CPVC piping systems have been installed and operated since 1959, and initial installations are still performing faultlessly. CPVC piping will not fail prematurely due to corrosion, electrolysis, or scale build-up in areas where water, soil, and/or atmospheric conditions are aggressive.

 

[Zorba]

I just did a search for 'brittle cpvc' doesn't look like i'm the only one that has noticed it. Lots of people calling cpvc junk. One even said 3 yr old flowguard was becoming brittle

I think it is widely accepted the PVC goes brittle over time. Really all plastics do eventually.

 

[DrPizza]

Kaido, sharkbite fittings are more for homeowners making a repair, not for doing entire homes. It'd be silly to do that. If you're going to replumb an entire house, it'd be foolish to worry about sleeving the pex indoors. Use a homerun system instead. I don't think I've ever heard of pex bursting - the only failures (that I've ever heard of, including online) are due to bad fittings or improper installation of fittings.

What a homerun system is: manifold for hot water and manifold for cold water at the source. Then, you run a separate pex line for every fixture in the house. So, if you have a dishwasher, you run a hot water line from the manifold to the sink. And you run a hot water line from the manifold to the dishwasher. NO tees. NO elbows. The only connections are at the manifold and at the fixture - it's one solid piece of pex in between. I can't figure out why people are so worried about elbows and tees inside of walls eventually failing. If you're using tees and elbows, you're completely missing the advantage of pex.

Yes, it does mean a lot more feet of pex. However, you save money by having fewer fittings. Pex runs around 1/3 the cost of copper. So, let's say you end up with 3 times the distance of copper pipes. You break even on that cost - but you save quite a bit on the lack of fittings. And, you save a lot more on time. And, you have more piece of mind.

And, for FSM's sake, just buy a $30-50 crimp tool, and 50 cent fittings, rather than $7 for every single fitting. Sell the crimp tool on ebay when you're done. (Or use the expansion method with the expansion sleeves; more expensive tool.)


If you have a line that freezes in extremely cold weather, the lack of fittings in the middle of the run means you're not likely to experience an extreme pressure build-up that's going to force the fitting off the pex. I doubt you're going to get pex to burst from a frozen line - it'll just stretch, then return to normal size when the ice is gone again. The same can't be said for CPVC or copper.

 

[DrPizza]

http://www.*********************/item/4829/three-designs-for-pex-plumbing-systems...

 

[Kaido]

Kaido, sharkbite fittings are more for homeowners making a repair, not for doing entire homes. It'd be silly to do that. If you're going to replumb an entire house, it'd be foolish to worry about sleeving the pex indoors. Use a homerun system instead. I don't think I've ever heard of pex bursting - the only failures (that I've ever heard of, including online) are due to bad fittings or improper installation of fittings.

Yeah, I've seen the homerun systems with the central manifolds, they look really nice!

As far as home design goes, my ideal setup would be a raised foundation with a single story using a sealed crawlspace system - that would make working on the system easy & keep the pipes largely out of the walls & ceiling (aside from residential fire sprinkler systems). Although I'd imagine there's more risk to freezing, not sure how insulated those sealed crawlspace systems are...

 

[Kaido]

Aww yisss

 

[Greenman]

After evaluating the installation issues I had, and looking at what was available locally, I ended up going with copper. Type a Pex simply didn't offer an improvement in quality or a simpler instillation.
Type c Pex would have saved in material cost, and a little bit on labor. But all I can get locally is a Chinese brand with a name I've never heard of. Chinese building materials don't have a real good track record.

 

[Kaido]

After evaluating the installation issues I had, and looking at what was available locally, I ended up going with copper. Type a Pex simply didn't offer an improvement in quality or a simpler instillation.
Type c Pex would have saved in material cost, and a little bit on labor. But all I can get locally is a Chinese brand with a name I've never heard of. Chinese building materials don't have a real good track record.

You're going with something standard & reliable, which is always a solid choice :thumbsup:

 

[DrPizza]

Aww yisss

Gotta love that. So organized.
And, if you're going to have a raised foundation with a sealed crawlspace, why not go with a basement? (Unless local geography - bedrock or very high water table - prevents it) Especially for a single story house. Digging the foundation out is pretty simple in most areas; hardly takes any time at all. If done right, to prevent future problems with water, it's got to be the cheapest way to double your available square footage. In many areas, if it's unfinished, it doesn't count against your taxes.

 

[Kaido]

Gotta love that. So organized.
And, if you're going to have a raised foundation with a sealed crawlspace, why not go with a basement? (Unless local geography - bedrock or very high water table - prevents it) Especially for a single story house. Digging the foundation out is pretty simple in most areas; hardly takes any time at all. If done right, to prevent future problems with water, it's got to be the cheapest way to double your available square footage. In many areas, if it's unfinished, it doesn't count against your taxes.

Just personal preference, had my share of basement problems in the past. One idea was just for flood-proofing & simple maintenance - have a raised foundation plus PEX in CPVC sleeves, no worries about pipes bursting, area flooding, etc. Just a couple simple tweaks to the standard home design to mitigate the potential of any issues down the road, and also to simplify maintenance. However, those are fairly non-standard setups, which tends to freak people out a little bit

I'm also a fan of open-concept designs & don't require a lot of storage (I also like built-ins a lot, so it'd be more of a per-room organization setup), so there's that too.

 

[Greenman]

Gotta love that. So organized.
And, if you're going to have a raised foundation with a sealed crawlspace, why not go with a basement? (Unless local geography - bedrock or very high water table - prevents it) Especially for a single story house. Digging the foundation out is pretty simple in most areas; hardly takes any time at all. If done right, to prevent future problems with water, it's got to be the cheapest way to double your available square footage. In many areas, if it's unfinished, it doesn't count against your taxes.

You would be absolutely astounded at how difficult it is to get rid of dirt here in the bay area. Most places charge $75 a ton to dump it. The one actual dirt dump that only charged $40 a truck load required the dirt to be tested for contamination before you dumped it.

Here in California we managed to make digging a hole into a major nightmare.

 

[Zorba]

You would be absolutely astounded at how difficult it is to get rid of dirt here in the bay area. Most places charge $75 a ton to dump it. The one actual dirt dump that only charged $40 a truck load required the dirt to be tested for contamination before you dumped it.

Here in California we managed to make digging a hole into a major nightmare.

lol, between my house and the highway there are at least three lots with signs saying "Free Dirt Dump - No Trash or Concrete" or similar.

 

[slashbinslashbash]

The PEX-inside-PVC system sounds like a good idea for the "belt and suspenders" crowd. One tweak might be to seal the ends of all the PVC around the PEX (drill a hole in a PVC cap, run the PEX through the hole, then fill with sealant). These caps would of course be at the very ends of the runs. Then if a leak occurred, the PVC would fill up and back up to the source (which might be a big open top pan with a drain). Have a single water sensor at that location that shuts off the main supply valve when it detects water. No need to install drains in every room then.

 

[Greenman]

The PEX-inside-PVC system sounds like a good idea for the "belt and suspenders" crowd. One tweak might be to seal the ends of all the PVC around the PEX (drill a hole in a PVC cap, run the PEX through the hole, then fill with sealant). These caps would of course be at the very ends of the runs. Then if a leak occurred, the PVC would fill up and back up to the source (which might be a big open top pan with a drain). Have a single water sensor at that location that shuts off the main supply valve when it detects water. No need to install drains in every room then.

Assembling such a system would be near impossible. Pex wont bend tight enough to fit inside PVC elbows, and trying to slide lengths of PVC over pex in between joists would be a nightmare. It would be considerably easier it install a solenoid valve at the main and a switch to turn it on or off at each point of use.

 

[slashbinslashbash]

Assembling such a system would be near impossible. Pex wont bend tight enough to fit inside PVC elbows, and trying to slide lengths of PVC over pex in between joists would be a nightmare. It would be considerably easier it install a solenoid valve at the main and a switch to turn it on or off at each point of use.

I was thinking this would have to be built-in when first constructing the home (or at least a to-the-studs remodel)... not something that could easily be retrofit into existing walls. Basically just treating the PVC as a conduit for the Pex, similar to how some people install conduit for signal cables (Ethernet/HDMI/etc.) to make later installation/upgrades/replacements/repairs easier.

The bending thing would obviously be a problem though. How tight will Pex bend? As mentioned upthread, using Pex elbows would kinda negate the "one continuous tube" benefit of Pex.

 

[Kaido]

Also, putting area drains in your kitchen and bathrooms, then sloping the floor towards them, will make them look like gas station bathrooms.

Arggg changed my mind, the bathroom gas station look is fine! Had a toilet overflow yesterday & by the time I got up there, there was half an inch of water flowing all over the place. Screw that! What a mess, took forever to clean up :thumbsdown: There has to be a better way...