AskCodeMan

As long as I can remember (and I've been looking for a plumbing code to support this installation but can't find it) when building on a slab, the trap is installed "below" the level of the finish floor. When a plumber is finished hooking up the drain, some plumbers fill the area around the trap with soil and pour soft tar into the hole on top of the soil. Some plumbers don't seal that space. What code covers this specific installation or is this "pouring tar in the hole to seal it" a "local plumber thing?"

Typically, at least in Florida, tub trap boxes are installed, such as this:
(right click over the link, select 'Open in new tab') https://ipscorp.com/plumbing/wp-content ... ub-Box.pdf

Then there are these from the IRC:
- R303.6 Outside opening protection. (this is one aspect of it: that hole is an opening to the "outside")
- R322.1.3 Flood-resistant construction. (that is another aspect of it)
- R506.2.3 Vapor retarder. (that is another aspect of it)

Thanks, Mr. CodeMan!