PVC Schedule 40 & PVC DWV

[readytowork]

I am installing PVC for bathroom drains in a residential home that is slab-on-grade.

Question 1: Should I use PVC Schedule 40 for pipes and fittings that are in and under the slab?

Question 2: Assuming the answer to Question 1 is Yes. How do I transition from PVC Schedule 40 for those under-slab pipes and fittings to PVC DWV pipes and fittings? I want to be sure that my connections between those two pipe types is good, durable, and tight.

 

[Jeff H Young]

pvc dwv sch 40 pipe is what your supposed to use? If its solid core pipe marked for potable water I would guess thats an issue with the marking but the od and id of pipe is identical, btw your fittings absolutely must be DWV rated just not sure if you can use pipe not clearly marked dwv . It wouldnt make sence but a lot of IOPC dosent make sence I dont work with PVC drainage except very rarely I use ABS

 

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[readytowork]

My plumbing supply store said that I should use PVC DWV for all of the plumbing (even under/through the slab). The store said that the DWV is not solid core. Does that sound like the correct thing to use for slab on grade drain/vent plumbing?

 

[Reach4]

The solid 3 inch and 4 inch schedule 40 is usually dual-rated for pressure and DWV.

While solid is stronger, it costs more. Normal couplings can connect foam core (DWV only) and solid.

Some PVC pipe for DWV is schedule 40. Some PVC pipe for DWV is not schedule 40. This is often called "thinwall", and is a different size. Schedule 30.

To connect schedule 30 and schedule 40, there are connectors and adapters made for the purpose. 3-inch schedule 30 is 3.25 OD vs 3.50 for schedule 49

https://www.menards.com/main/search.html?search="schedule+30" is schedule 30 thinwall.

https://www.menards.com/main/plumbi...600ha/p-3289655540164039-c-8571.htm?exp=false is a glue-on adapter

https://www.menards.com/main/plumbi...000600hc/p-1444426392542-c-8571.htm?exp=false is schedule 40 dual rated solid

https://www.menards.com/main/plumbi...000600hc/p-1444426392852-c-8571.htm?exp=false is foamcore DWV-only

 

[readytowork]

Helpful. Thank you.