#Thread bathtub overflow cover code#

Once this housing was in place some trip lever plate manufacturers cut a slot in the plate. This assembly required a housing to enclose the trip lever rod. The lever is attached to a rod which went down the backside of the tub and then under the tub to the drain where it attaches to the stopper. Second idea: A trip lever to move the tub stopper up and down. Their first idea was a solid plate mounted in the hole with a chain attached to the plate and a rubber drain stopper at the other end.

The molds for the tubs were so expensive that the manufacturers could not afford to change the mold to remove the hole. With the tub spout moved up on the wall, manufacturers were left with a hole that had no purpose.

Plumbing codes made this installation illegal. It was later learned that water from the tub could back siphon through the spout into the water supply. In other words, the original purpose for the hole was as a mounting point for the tub filler spout. Here is how bathtub overflows came to be: 100 years ago manufacturing molds for cast iron bathtubs had a hole for mounting a tub spout inside the tub.

#Thread bathtub overflow cover code#

This belief is also held by many building inspectors and building code officials. I haven’t researched this, but I think it would be a good idea to reach past for a good general answer to this question. In fact, I don’t think designing an overflow as a safety device is that difficult and I’m pretty sure It’s been done lots of times, since tubs are available that differ radically in design. I have to say that I don’t believe it costs millions and millions of dollars to re-design a tub mold. Taken from here… Are bathtub overflow drains required? - Answers Home buyers and new homeowners believe that bathtub overflows will prevent their bathtubs from overflowing due to an unattended filling operation. IAPMO recognizes that real bathtub overflows do not exist and therefore it would be pointless to require them. The Uniform Plumbing Code published by IAPMO (International Association of Plumbing and Mechanical Officials) does not require bathtub overflows.

The ICC (International Code Council) has recently issued a ruling that they do require bathtub overflows in the IRC (International Residential Code) and the IPC (International Plumbing Code).