# Power vent venting with foam core PVC



## Master Mark (Aug 14, 2009)

I am wondering if I have missed something concerning the 
installation of power vent units... 

I Gave someone an estimate tonight
and they claimed that others who also estimated their heater replacement today mentioned that if someone installed foam core pvc pipe vent, they would have to remove it and install Sch40 pvc to meet code....

I would normally run Sch 40 myself but I have on occasion run into foam core installs before...and I have never noticed a problem with it..
I have never considered tearing out the whole line and re-doing it and am wondering about this....

so is this an issue and concern that has slipped by me, or is the other plumber just trying to pump the homeowner for another 700 bucks??.


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## Master Mark (Aug 14, 2009)

is there anyone still on this site since being booted off last month??


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## justme (Jul 4, 2012)

My problem with foam core piping being used as venting material is that the **** can easily have a crack in it that normal pvc wouldn't normally have.


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## paultheplumber1 (May 1, 2014)

I usually use regular PVC for the venting. But I do use foam core for all my drains. Some man specs say it's ok.


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## paultheplumber1 (May 1, 2014)

And what a ***** getting signed back up here. There should be a note saying "must use a computer to log in and reset password"


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## Master Mark (Aug 14, 2009)

I talked to my Rheem guy today and they claim it has always was supposed to be sch40 heavy duty pipe used for power veinting..... They claim that if a unit runs hotter than normal it will melt the inside of the pipe and it will cave in on itself blocking the vent....



I have never seen this happen before and have never seen a picture of what they are talking about happenning.... You would think that the water heater companies would have some sort of warning right on the outside of the box stating the vent MUST be run in sch40 but I have never seen one to this date..

anyway I go out today and sure enough a big tract home plumber in our town has run the whole line out of foam core about 9 years ago.... All the line had to be was 2 inch but he ran a 3 inch line and I wonder if that is how they skirted this issue...

.I cut out about half of the line and replace it with sch 40 and give him a price to replace the rest on another trip which probably will never happen.....

but I made a note about the situation 
and the pipe looked perfectly fine to me..


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## moonapprentice (Aug 23, 2012)

M.M., the company I work for used to run foam core. Now we run solid core. Some new inspectors in town caught the fact that bradford whites manual allowed foam core, but then changed over to solid core.
With that being said, if there were lots of issues with foam core we wouldn't have used it. 

From what I have seen with foam core failing, is on OLDER water heaters, when they are not running efficiently and working harder producing more heat. (Same goes for dysfunctional w.h.s, or maybe t-stat too high?) Most common I've seen has been slight discoloration from white color to a tan color. I have seen a vent that got dark brown in color. The pipe was fine but the FITTING had a spot that collapsed, still enough to breath good though.

I guess my take on it is foam core is OK (even tho specs say no). IF you maintain your w.h. yearly. Most homeowners don't do that, so to be on safe side 10 years down the road the solid core will supposedly handle the hard working w.h. and not be a fire hazard too.

I'm sure you knew most of this, but just wanted to share my experiences


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## Green Country (Mar 6, 2009)

paultheplumber1 said:


> I usually use regular PVC for the venting. But I do use foam core for all my drains. Some man specs say it's ok.


Don't want to derail the thread, but why do you use foam core for drains?


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## Master Mark (Aug 14, 2009)

moonapprentice said:


> M.M., the company I work for used to run foam core. Now we run solid core. Some new inspectors in town caught the fact that bradford whites manual allowed foam core, but then changed over to solid core.
> With that being said, if there were lots of issues with foam core we wouldn't have used it.
> 
> From what I have seen with foam core failing, is on OLDER water heaters, when they are not running efficiently and working harder producing more heat. (Same goes for dysfunctional w.h.s, or maybe t-stat too high?) Most common I've seen has been slight discoloration from white color to a tan color. I have seen a vent that got dark brown in color. The pipe was fine but the FITTING had a spot that collapsed, still enough to breath good though.
> ...



I dont know all that much, its all a blur and I just stumbled onto this issue
yesterday..... Like I said they oversized the power vent line to 3 inch and reduced it down in the last 4 feet to 2inch.... Perhaps with the extra volume and oversizeing the line, its not a concern 

I have also seen some 25 year old stuff that basically had turned brown inside and it seemed that sometimes the glue in the joints became fragiel and the 3 inch fittings would break loose when fooling with them 

but I have yet to see an actual closure in the pipe....or a picture on the internet of one in a real world setting....maybe its a one in 10 million occurrence..... 

It makes me wonder if sometime down the road they will expect older brown crusty vent lines to be replaced when installing a new unit...


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## plumberkc (Jun 23, 2011)

Solid core here.


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## rwh (Dec 17, 2014)

What is the price difference, percentage wise? Why wouldn't you use sch 40 solid core all the time? At least on non dwv applications. Large jobs dwv/vent I can see the potential? 20ft power vent ? Why bother


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## Green Country (Mar 6, 2009)

rwh said:


> What is the price difference, percentage wise? Why wouldn't you use sch 40 solid core all the time? At least on non dwv applications. Large jobs dwv/vent I can see the potential? 20ft power vent ? Why bother


That's why I was asking as well. Even on a big residence you may save what, $100? Not worth it for me. I've dug up 3" cell core that was only in the ground about a year and it was already flattened some.


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## Plumbus (Aug 4, 2008)

From the Charlotte Pipe web site;
Failure to properly vent combustion gas may result in
serious injury or death from carbon monoxide.
• Always install / use pipe or fittings as specified by the
appliance manufacturer's installation instructions to
vent appliances.
• Never use PVC or ABS cellular core pipe for combustion
gas venting.


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## paultheplumber1 (May 1, 2014)

We use foam core piping on drains for a couple reasons. Mostly because it's lighter and easier to cut. It is a little bit cheaper as well but not alot. I don't do much commercial work, very rarely do I ever have to do a slab but if I do i use pressure pipe underground. We are a small company and most of the time our new construction jobs are handled by one man. It's a big difference trying to hang a 20' length of 3" foam core vs pressure pipe when your alone.


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## rwh (Dec 17, 2014)

paultheplumber1 said:


> We use foam core piping on drains for a couple reasons. Mostly because it's lighter and easier to cut. It is a little bit cheaper as well but not alot. I don't do much commercial work, very rarely do I ever have to do a slab but if I do i use pressure pipe underground. We are a small company and most of the time our new construction jobs are handled by one man. It's a big difference trying to hang a 20' length of 3" foam core vs pressure pipe when your alone.



Those reasons will not sell me on cell core. Have never seen cell core in true commercial, unless contractor was trying to slide in a fast one. Of course they would never think of doing that.


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## JohnnieSqueeze (Mar 23, 2016)

what about for a condensing tankless unit? i used foam core should i change it out? Just discovering this. The house is hard wired with carbon monoxide detectors


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## ShtRnsdownhill (Jan 13, 2016)

JohnnieSqueeze said:


> what about for a condensing tankless unit? i used foam core should i change it out? Just discovering this. The house is hard wired with carbon monoxide detectors
> 
> 
> Sent from my iPhone using Tapatalk



I would, as you just set yourself up for a major liability if anything goes wrong...
PVC Schedule 40 Foam Core Pipe is for DWV purposes only. It is for Non-Pressure systems where temperatures will not exceed 140° F. It is coextruded and has a cellular core. PVC Schedule 40 Foam Core is lightweight, non-toxic and easy to install. Installation requires primer and solvent cement. 

https://www.google.com/url?sa=t&rct...am_core.aspx&usg=AOvVaw0qZWlOWit1nSuWoBNOsDYR


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## Venomthirst (Jun 20, 2018)

636 or whatever royal pipes system is are cheap I wouldnt even think about risking using other systems.. Abs was legal here at one point but now it has to be pvc rated for flue gas... your allowed to leave abs if its fully exposed and in good shape but i change it out anyways... always use a pipe cutter with plastic wheel and bevel... thats what manufacture wants us to do thats what i do.. 

I Take zero chances when it comes to gas burning appliances.. I install exactly to manufactures specification and according to b149.1... The guilt i would feel if anything goes wrong... Ive even shut my own friends gas off because he wasnt taking the matter at hand I seriously... i wrote up an A tag and dropped it in his mailbox... I wasnt going to let him or his children die because hes too incompetent to realize the serverity these things can cause


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## dhal22 (Jul 30, 2010)

JohnnieSqueeze said:


> what about for a condensing tankless unit? i used foam core should i change it out? Just discovering this. The house is hard wired with carbon monoxide detectors
> 
> 
> Sent from my iPhone using Tapatalk


No shortcuts in my book. Pays off in the long run.


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## Tango (Jan 13, 2018)

dhal22 said:


> No shortcuts in my book. Pays off in the long run.


It's exactly the consideration I take on every job I do as a OMS. I can get into trouble so quick it's not funny. 

Big companies don't care, they have the funds or have mafia contacts or can screw the systems with so many lies they can't catch them all and get away with most.

If I see something not to code in my work space I write it down on my work order and take pictures. BEFORE AND AFTER PICTURES. Someone eventually will blame me under false accusation like I'm presently involved. I'm beginning to think of getting a body cam.


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## Master Mark (Aug 14, 2009)

Tango said:


> It's exactly the consideration I take on every job I do as a OMS. I can get into trouble so quick it's not funny.
> 
> Big companies don't care, they have the funds or have mafia contacts or can screw the systems with so many lies they can't catch them all and get away with most.
> 
> If I see something not to code in my work space I write it down on my work order and take pictures. BEFORE AND AFTER PICTURES. Someone eventually will blame me under false accusation like I'm presently involved. I'm beginning to think of getting a body cam.




Actually a body cam is not a bad idea or keeping your cell phone filming in your front pocket while you are on a call.....

after the shameful situation with judge Kavanaugh getting smeared from a nut over a high school party 40 years ago its probably not a bad idea.....

any lady can claim anything today and you are automatically guilty... I was recently in a home with a smoking hot wife and if she were a nut she could claim anything and then I got a mess on my hands..... 

your name and reputation gone over night, just because you were 30 dollars too high on the bill-- 
Now, -if you had the whole call on your cell phone you could probably have them arrested and SUE THEM...I could see their eyes go wide open when you tell the police you have the whole call all on film.....


I think that if I were on the east or west coast or maybe up in your socialist crazy Canadian town, I would be looking into a body cam ....most folks in the mid west are fairly tame... 

Being as handsome as I am, I can think of a lot of situations over my life that could have gone south---you got to protect yourself from those cougars....


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## Tango (Jan 13, 2018)

Master Mark said:


> Actually a body cam is not a bad idea or keeping your cell phone filming in your front pocket while you are on a call.....
> 
> after the shameful situation with judge Kavanaugh getting smeared from a nut over a high school party 40 years ago its probably not a bad idea.....
> 
> ...



One famous plumber (this ain't no taj mahal) seems to record all his work. He said some people blame him for issues he didn't work on because he was just there in the house.

One problem I see with that is if I forget to say one line like the law says, let's say I forget to say the service call in front of the cam is 50$ and if it goes to court they'll find a flaw even though it's written and signed on the work order.


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## Master Mark (Aug 14, 2009)

Tango said:


> One famous plumber (this ain't no taj mahal) seems to record all his work. He said some people blame him for issues he didn't work on because he was just there in the house.
> 
> One problem I see with that is if I forget to say one line like the law says, let's say I forget to say the service call in front of the cam is 50$ and if it goes to court they'll find a flaw even though it's written and signed on the work order.


No one needs to know they are being filmed..... and most times they are not going to be standing over you watching ..... 

who was this famous plumber you are talking about>

I think that Dunbar Plumbing would probably do this :vs_laugh:>>??


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