Fernco

Fernco couplings connect pipe ends for contractors handling plumbing, drain and sewer repairs. The range includes connections for mixed underground pipe materials and above-ground drain, waste and vent transitions. You choose the coupling around the pipes you have and the location of the joint.

Fernco began in a master plumber’s garage in Michigan in 1964. Its headquarters and manufacturing operations are in Davison, Michigan. The company manufactures flexible pipe couplings and connection products for plumbing, water, sewer and infrastructure repair.

Repair and reducing connections

Fernco makes flexible PVC connections for waste, vent, sewer and drain applications. Whether you’re making a same-size repair or a reducing connection, the size stamped on a pipe is a starting point. Pipes with the same nominal size can have different outside diameters, especially when the materials change. Both ends need checking.

For a reducing connection, record the material and size for each side separately. Measure the outside diameter of each pipe end, then compare both measurements with Fernco’s sizing information and technical drawings.

Couplings for mixed pipe materials

Fernco has couplings for joining different pipe materials. The location narrows the choice: underground transitions and above-ground drain, waste and vent repairs have distinct coupling applications.

Coupling type	Application
Universal coupling	Connects unknown or mixed underground pipe materials.
Shielded RC coupling	Serves underground pipe transitions.
Specialty shielded coupling	Connects common drain, waste and vent pipe materials in above-ground applications.

Frequently Asked Questions

What is a Fernco coupling?

A Fernco coupling is a flexible connection that joins pipe ends for plumbing, waste, vent, sewer and drain work. It’s used for repairs and transitions, but the application matters: a coupling intended for an underground joint isn’t automatically suitable for an above-ground repair.

How do you choose the right size Fernco coupling?

You choose a Fernco coupling by the pipe material and outside diameter at each end. Matching nominal sizes alone doesn’t establish a fit. For a reducing connection, each end needs to match its own pipe, so both measurements matter.

Can a Fernco coupling join different pipe materials?

Yes. Fernco offers connections for mixed underground pipe materials and specialty shielded connections for common above-ground drain, waste and vent materials. That doesn’t make every coupling interchangeable; you need the specific connection to suit both pipes and the location.

How do you install a Fernco coupling?

Start by checking that the Fernco coupling matches both pipe ends and is intended for the location of the joint. Follow that coupling’s installation instructions for pipe preparation, positioning and clamp tightening. Tightening by feel isn’t a substitute for the specified clamp torque.