TOPIC: TPR valves

Do new homes have to have the TPR valve go outside or just down to the floor?

Either is fine.  Well, that being said, it depends on whether your installation is inside the home or inside the garage or basement.  I would not have a drain line terminate inside the home near the floor due to potential damage.  If it was in the garage, then fine.  Of course the best is to have it go completely outside.

IRC 2006
R2803.6.1 Requirement for discharge pipe.  The discharge piping serving a pressure-relief valve, temperature-relief valve or combination valve shall:

1. Not be directly connected to the drainage system.
2. Discharge through an air gap located in the same room as the water heater.
3. Not be smaller than the diameter of the outlet of the valve served and shall discharge full size to the air gap.
4. Serve a single relief device and shall not connect to piping serving any other relief device or equipment.
5.Discharge to the floor, to an indirect waste receptor or to the outdoors.  Where discharging to the outdoors in areas subject to freezing, discharge piping shall be first piped to an indirect waste receptor through an air gap located in a conditioned area.
6.Discharge in a manner that does not cause personal injury or structural damage.
7.Discharge to a termination point that is readily observable by the building occupants.
8. Not be trapped.
9. Be installed to flow by gravity.
10.Not terminate more than 6 inches above the floor or waste receptor.
11. Not have a threaded connection at the end of the piping.
12. Not have valves or tee fittings.
13. Be constructed of those materials listed in Section P2904.5 or materials tested, rated and approved for such use in accordance with SAME A112.4.1.

Either is fine.  Well, that being said, it depends on whether your installation is inside the home or inside the garage or basement.  I would not have a drain line terminate inside the home near the floor due to potential damage.  

Stan, you have water heaters inside the living areas of homes in WA?? Why? You got your garage, attic and basements to put them in. Even if you did, you can't have it terminate inside the living area. We don't have basements in my area but WH's are put in garages and/or attics here and TPR drain lines are terminated to the outside where visible and w/ acceptable material.

Either is fine.  Well, that being said, it depends on whether your installation is inside the home or inside the garage or basement.  I would not have a drain line terminate inside the home near the floor due to potential damage.  

Stan, you have water heaters inside the living areas of homes in WA?? Why? You got your garage, attic and basements to put them in. Even if you did, you can't have it terminate inside the living area. We don't have basements in my area but WH's are put in garages and/or attics here and TPR drain lines are terminated to the outside where visible and w/ acceptable material.

Yep.  There are lots of inside water heaters, like mine.  And there are homes without a garage.  I have only run into 2 attic water heaters in over 2000 inspections.  Not very common up here.  My inside termination comment was for basements but there are many that terminate inside the home as well.  Best scenario is to terminate outside.

Steve, you say (copy and paste- your comment) My inside termination comment was for Basement. But look here-(copy and paste original comment) I would not have a drain line terminate inside the home near the floor due to potential damage. What? you're gonna have damage in the basement? Fessup
(copy and past, your qoute) I have only run into 2 attic water heaters in over 2000 inspections.  You are misdirecting Steve, I said attic, garage or basement. We don't have basements here so we do use attics for water heaters, rarely. Garage water heaters here. School me on the WH's in the living area. Out of coriousity where do you put inside wh's? Here instead of inside wh, if needed, you put wh at exterior wall w/ exterior door, yes to outside. Why would anyone anywhere have WH's inside living area?