Hello everyone.

I am current in process of converting my empty basement into something more enjoyable. I have reached the point where I want to put up the walls of the bathroom. Before I can do this I need to put in the rough in plumbing connection for the bathroom. I have to cut the basement floor to get to the main sewer line to join the drain lines from the bathroom to the main sewer line. Once the floor is cut and I have access to the main sewer line I plan on inserting a necessary Tee fitting into the main line. My problem is this, there will not be any play with the main line to get a tee fitting place and I need to use some type of coupling. What type of coupling? If I use the Fernco coupling can this be put into the ground and cemented over. And is there anything special that needs to be done to it before I do so. Or do I user a PVC repair coupling. However I read nothing but hoar stories when people have tried to use this with the glue drying to fast and not being able to get the coupling in place. That or they get it in place but it ends up leaking. Other people thoughts and experiences are welcome at this point.

Unless local code states otherwise, I would use a shielded no-hub coupling, without giving it a second thought.

i too have bad luck with repair couplings. in your case it could be even worse since you will be working with plastic pipe that has been buried and the walls just are not new and smooth.

Use a "shielded no-hub coupling". You'll have to 'roll' it back on itself (both of them, either end) halfway to get it in place but not too difficult.

I agree a shielded coupling is best. PVC repair couplings are fine on a theoretical level, but they are a stinker to install and you only get one shot. Buried, I don't have a problem with the all rubber coupling, but the correct shielded one is better.

Thanks everyone for there quick response.

This is not the only forum that I post this question to. The answer I have gotten have been about 50-50 Some people say go with the repair PVC coupler and other say go with some type of Fernco coupler.

I decided to attempt the PVC coupler. I feel cemented PVC coupler is far better than having a rubber coupler held on with a clamp that over time could rust or corrode off.

I have found slow setting PVC cement that takes 3-4 time longer to set then normal cement. This should allow me time to get the PVC coupler in place before the cement hardens and locks the coupler in place.

I am going to try the slow setting PVC cement on some extra PVC pipe & fitting I have and see how it preforms and if the lock in time is longer. If so I will attempt on the main sewer line, let the cement dry and leave the main sewer line exposed for a week.
Then when some takes a shower or something long running I can look to see if the coupler leaks. If it does leak then I can remove it and then use the Fernco coupler. If it does not then I am far better off having like for like material and no chance of the clamps rusting or corroding off over time.



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The shielded no-hub couplers are stainless steel(won't rust).

IF you think "tees" are the correct fittings for your connections, you should NOT be doing this installation yourself.

HJ

Thank for your advice. I understand how water flows and that the least path of resistance is needed. There are many types of tee's, PVC Test Tee, Bull Nose Tee, so on and so forth. I do believe, provided that my main line is 90deg from my newly install waste line, that the part that I need to connection to my main line is called Sanitary Tee PVC DWV. A sanitary tee is used in residential and commercial drain, waste and vent systems The PVC DWV sanitary tee features a hub x hub x hub connection and a flowing sweep to aid in the evacuation of waste and used fluids. The tee allows for a connection to be made in continuous pipeline and branch out to a different direction. All this depends on if my main line is at 90deg of the newly installed drain line. However if it is not and it is at say a 45deg then I know that I have to use some type Wye connector. What type of connector I use will be based off what I discover when I cut up the cement and expose the main sewer line. In want a connector that promotes the flow of water in the direction that the main sewer line natural flow. This much I understand.

What I am I still not clear on the connector type. Some people say go with the repair PVC coupler and other say go with some type of Fernco coupler. I feel cemented PVC coupler is far better that having a rubber coupler held on with clamps that over time could rust or corrode off. I have found slow setting PVC cement that takes 3-4 time longer to set then normal cement. This should allow me to get the PVC coupler in place before the cement hardens and locks the coupler in place. I think I am going to try this first, let the cement dry and leave the main sewer line exposed for a week and look to see if the coupler leaks. If it does then I can remove it and then use the Fernco coupler.

A sanitary tee is installed in a vertical drain pipe and the branch is a horizontal inlet. If you are tieing into a horizontal drain pipe, you need to use a wye or combo.

"All this depends on if my main line is at 90deg of the newly installed drain line. However if it is not and it is at say a 45deg then I know that I have to use some type Wye connector."

I am just a DIYer not a plumber but this is false. The location and angle between the two pipes do not dictate whether you use a WYE or SANITARY TEE.

My understanding is if you are draining from a horizontal pipe into a vertical vent/drain pipe, the connection should be a sanitary tee, because that vertical pipe is acting as a vent too. If you are merging a horizontal drain into another horizontal drain you need to use a WYE or COMBO, not a SANITARY TEE. The WYE is a more gradual transition and gives you some freedom to roll the fitting up partially if the elevations are not even, also in the event you need to snake the line in the future, a WYE fitting is much easier to navigate through but a SANITARY TEE lying down on it's side can be a challenge. That's my understanding from reading the pros on this site.

As for whether a shielded coupling is preferred over a repair coupling. I think if everything else being equal I too would prefer a repair coupling. However for practical reasons I would use shielded couplings because #1 - I think it is very difficult to install a larger diameter pipe with repair couplings you would have to glue both sides at the same time, slide both repair couplings on, insert the piece, slide both repair couplings back down to make the joint, while making sure the branch of the fitting is rolled to the right angle, and if you are working in a tight space at an awkward angle, it's a big challenge; also #2 sometimes the branch of the fitting will need to be rotated slightly to fit the pitch of the pipe coming in, with a Fernco you can loosen the coupling and adjust with the repair couplings you are stuck.



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