Pvc venting

CBRob

I've heard that foam core pvc is not approved for venting condensing boiler.
Is that true for all boilers, and does cellular core mean foam core?

Zman

Yes, cellular core is the same as foam core. It is OK for combustion air piping. I don't know of a boiler manufacture that allows cellular core for venting.

ChrisJ

Separate subject but, I didn't know hose clamps worked on PVC?

JUGHNE

I wonder if there is a rubber type gasket missing from that connection?

DZoro

The gasket is just below the band. The band is just holding the pipe from coming out.
Others are correct no cell core on exhaust, personally not even on intake. Too easy to get mixed up during installations.
D

CBRob

Uh oh...
This is the exhaust side.

I've got a feeling it's the same pipe all the way to the roof.
And probably the same on 10 of these houses.

How big of a deal is it?
I hate to be an alarmist with informing owners.

ChrisJ

CBRob said:

Uh oh...

This is the exhaust side.



I've got a feeling it's the same pipe all the way to the roof.

And probably the same on 10 of these houses.



How big of a deal is it?

I hate to be an alarmist with informing owners.

If it's against code and not approved by the manufacturer I don't know.

I guess it depends on if something goes wrong or not.

Steamhead

I would alert the owners and make whoever put it in eat the replacement cost.

JUGHNE

My son's condo had used cell core for his condensing furnace.
A lot of horizontal pipe. Stains in the ceiling. Combination of bad glue joints, sagging pipe and lack of support. Enough sag that you could hear water bubbling and suddenly a blast of water coming out.
Problems were not necessarily because of cell/foam core pipe but it's use was another item indicative of a cut corners and get it done job.
I told him to talk to the contractor about it.
They redid several 5 unit condos at their expense and also sheetrock repair included. (I was surprised)
The HVAC sub had sub-let the original job out.

ChrisJ

JUGHNE said:

My son's condo had used cell core for his condensing furnace.
A lot of horizontal pipe. Stains in the ceiling. Combination of bad glue joints, sagging pipe and lack of support. Enough sag that you could hear water bubbling and suddenly a blast of water coming out.
Problems were not necessarily because of cell/foam core pipe but it's use was another item indicative of a cut corners and get it done job.
I told him to talk to the contractor about it.
They redid several 5 unit condos at their expense and also sheetrock repair included. (I was surprised)
The HVAC sub had sub-let the original job out.

What is foam core actually intended for?
Outdoor drainage? Is it actually used indoors for DWV?

roelandp

are there orange stickers saying 636 on the fittings

roelandp

this is an approved venting system in canada if it has stickers and pipe that says 636 were do you live

JUGHNE

The big clue on the labeling I noticed in the OP earlier post states not for pressure. DWV only.
(Regular 3" sch 40 dwv is rated for 260PSI at 73 degrees F.
.........even that's scary isn't it. )
Foamcore is light weight. PVC shell outside and inside. The wall thickness is made up with high density foam sandwiched between the shells. Just picking it up the weight will tell you.

Check some out at the big box, just compare weight and price.
Not a lot of savings unless you are doing a lot of pipe IMO.

CBRob

These houses are passed the contractor warranty. For the state of Colorado. I think it's 6 years here. So the homeowners would be on their own.

GroundUp

Some places cellular core is acceptable. One of my competitors here uses it for everything and always has, passes inspection every time. Personally I use solid for everything, so it doesn't get mixed up, and it's an extra dollar per job so I have no idea why anybody would try foam core in the first place

ChrisJ

> @JUGHNE said:
> The big clue on the labeling I noticed in the OP earlier post states not for pressure. DWV only.
> (Regular 3" sch 40 dwv is rated for 260PSI at 73 degrees F.
> .........even that's scary isn't it. )
> Foamcore is light weight. PVC shell outside and inside. The wall thickness is made up with high density foam sandwiched between the shells. Just picking it up the weight will tell you.
>
> Check some out at the big box, just compare weight and price.
> Not a lot of savings unless you are doing a lot of pipe IMO.

No, that's not scary.

It's rated different pressures at different temperatures just like any pipe.

JUGHNE

Yes, true, but it is still PVC.
The very few times I have had to deal with any pressure above 50 PSI for PVC, Sch 80 was used. You can even thread that.

But being old school I don't even trust CSST either.
I know.....old guys.
However if I were doing cast iron DWV when PVC came along I most likely would have embraced that pretty fast.
And if I were 40 years younger I would even get PEX tools.
Still only copper or someone else does it.

Jolly Bodger

Cellcore is only designed for Drain Waste Vent. And the vent they mean is plumbing vent not combustion vent. Cellcore has very low heat tolerance and will breakdown/sag. If you are installing a Boiler or water heater, the approved venting is dependent on what temperature the appliance is going to run at. That directly affect the flue gas temperature.

Two things make this acceptable or not. The AHJ (authority having jurisdiction, local building department) and the UL listing. New construction so the AHJ signed off on it. This might mean it meats the local code or it might mean the inspector did not catch it.

But if Cellcore pipe is not an approved venting material by the manufacturer and approved for the application (temp). Then the installation Voids the UL listing. An insurance company might have a problem with that.

Alan (California Radiant) Forbes

Polaris water heaters still show that PVC is approved for vent and air intake pipe.