I inspected a home on a slab where the water heater was near the center of the house in a closet. They routed the TPR discharge pipe through the wall into the attached garage where it terminated 6" above the garage’s concrete floor.
Usually I see them routed to the exterior. Is terminating it in the garage acceptable?
Via air gap or above floor in the same room. If there is no alternative, final termination in the garage could be acceptable per AHJ.
Well, I suppose there were alternatives to terminating it in the garage. They could have just run it straight down to the closet floor, or after running it through the wall to the garage, they could have added an elbow and kept extending it out through the garage wall to the outdoors.
Peter the effort the plumbers intended was for the occupant to observe water from the TPRV when they piped it to the garage. This should prompt the occupants to call a plumber.
I would have no problem with it terminating at the garage if there was a floor drain or the garage floor sloped towards the main vehicle entryway.