Bathtub Building Code Problem
Bathtub building code problems like
this aren't usually a big problem for most remodeling contractors. It
seems like most remodeling contractors who work on bathrooms, have a
pretty good idea and working knowledge of how plumbing traps and drains
like these work.
Even though you might not ever have a problem with this type of drain, most building codes state that any bathtub traps like these, that have any type of connections that cannot be permanently sealed, need to have an access door.
Whatever you do, don't quote me on my example of what the building code actually says. If the contractor would have installed a plastic waste and overflow that could be glued together, with out any removable connecting parts and attached the waist and overflow to a bathtub trap that was also glued and didn't have any removable parts, you wouldn't need an access panel in the ceiling.
One of the biggest problems with this type of bathtub draining system is that the connections could eventually leak. If you didn't have an access door in the ceiling like the building code would require, you would find yourself repairing the drywall ceiling eventually.
Some building codes might sound a little ridiculous, but most of them were created to solve problems and eliminate safety issues. If you're not planning on using your local building department to inspect your bathroom remodeling projects, the least that you could do, is follow the building codes.
When I run into problems like these, they are usually from the previous homeowners. If you're planning on remodeling your bathroom, plan on doing it right, so that the next homeowners don't have to suffer from your mistakes.