Fernco Couplers

[Jeff Knecht]

HI
Can Fernco Couplers be used in walls and a crawlspace?
I've read, which can be dangerous, that they are only approved for below groundwork, yet I have seen them used by bonafide professional plumbers in crawlspace and buried in a plumbing wall.

I'm referring to two types:
One has a shield covering the entire rubber coupler.
The other is a rubber coupler with clamps at each end.

Thank You

 

[wwhitney]

The ~2" long fully shielded style (flat shield; corrugated is a no-hub coupling only for cast iron to cast iron) is rated for above ground use only and can be concealed.

The ~ 4" long not-necessarily shielded (and when shielded, the ones I've seen have 2 clamps on each end, only one of which overlaps the shield) style is rated for underground use only.

I believe there is one more style that is rated for either above ground or below ground use, but it is newer and I've not seen them.

Cheers, Wayne

 

[Sponsor]

 

[Sylvan]

Never would I trust an unshielded coupling

I use No hub couplings to connect NH CI to PVC , galvanized etc with no problems


https://www.anaco-husky.com/products/husky-4000-series/

 

[Mr tee]

I agree with sylvan. Shielded couplings are approved underground, that is what is used on cast iron.

 

[wwhitney]

It was news to me, but Fernco Proflex is not rated for underground use. Per https://www.fernco.com/plumbing/shielded-couplings/proflex-couplings "Proflex connects cast iron, plastic, steel, copper and tubular, drain waste and vent systems for above-ground applications." And the listing is to "ASTM C1460" which is titled "Standard Specification for Shielded Transition Couplings for Use with Dissimilar DWV Pipe and Fittings Above Ground"

Underground couplings need to be listed to ASTM C1173, "Standard Specification for Flexible Transition Couplings for Underground Piping Systems". If you want a Fernco shielded underground coupling, it should be one of their Strong Back couplings, e.g. RC 1000:

https://www.fernco.com/plumbing/shielded-couplings/strong-back-rc-couplings

Cheers, Wayne

 

[wwhitney]

PS ASTM C1461 is the standard for dual use above ground/below ground couplings: "Standard Specification for Mechanical Couplings Using Thermoplastic Elastomeric (TPE) Gaskets for Joining Drain, Waste, and Vent (DWV), Sewer, Sanitary, and Storm Plumbing Systems for Above and Below Ground Use"

I've never seen an ASTM C1461 coupling in person, Fernco doesn't make any. Here's a link to one product:

https://www.anaco-husky.com/products/cremco/rigid-quik-couplings/

Cheers, Wayne

 

[Jeff Knecht]

The ~2" long fully shielded style (flat shield; corrugated is a no-hub coupling only for cast iron to cast iron) is rated for above ground use only and can be concealed.

The ~ 4" long not-necessarily shielded (and when shielded, the ones I've seen have 2 clamps on each end, only one of which overlaps the shield) style is rated for underground use only.

I believe there is one more style that is rated for either above ground or below ground use, but it is newer and I've not seen them.

Cheers, Wayne

Thanks again, went with the shielded coupler.

 

[Jadnashua]

Fernco is a large company, that makes numerous plumbing bits...so, it's a little bit confusing when you call one of them simply a Fernco. Other companies make them, too, so it gets more confusing.

You need on of the shielded couplings above ground to ensure the two ends of the pipe can't shift. It's assumed that when using one underground that you'll grade and backfill carefully enough to prevent that from happening, but that doesn't always happen, so a suitable shielded one make more sense, except they may cost more, which might dictate which one gets used.

Inside of a shallow wall, the all rubber one may stick out beyond the stud, and that can be a problem, too. The shielded one, if you get the head in the right place, is thinner and will fit, generally.

 

[Jeff Knecht]

Good explanation and thank you.

I did try to point out the two types of Fernco products that I was referring to.

Take Care