repair of 4-inch clay sewer

[ed fox]

Im searching for the best type of coupling for joining 4-inch clay pipe to 4-inch PVC. My primary concern is root penetration. Is a Trifluralin impregnated coupling available?

 

[LonnythePlumber]

Herbicide

I've not heard of a herbicide impregnated rubber coupling. You're still going to have clay that will have to be replaced anyway.