I have a second floor laundry room with a washer/dryer and a hot water tank. My current plan is to install a floor drain near the center of the room (sadly the floors aren't sloped at all). I will have the drain pan from the water heater empty directly over the drain, and I will run my own copper piping from the T/P valve to a few inches over the floor drain.

Here are my current thoughts on how to pick a drain:

- A circle will be easy to cut evenly with a hole saw. A square will be easier to goof up. So I'd prefer the former. This floor is brand new LVP and I'd rather not make this look unnecessarily ugly due to cutting errors.

- I think I'd like a fairly large drain grate, about 5-6 inches, so that if the pan "dribbles" water it has a better chance of actually making it into the drain.

- I see a lot of drains that connect to PVC. But PVC wouldn't be able to handle 200 degree water from the T/P valve. Is it typical to use PVC for this application anyway, or should I look for something all metal?

- I would like to connect to 1" copper on the other side, and route that pipe to the outside of the structure. I have easy access under the floor.

Are there specific drain models that you'd recommend for this use case? Or should I just buy a cheapo PVC shower drain at Home Depot and call it a day?

To really prevent water damage you should remove all the flooring in the room , install vynil membrane in the entire room including 6” up each wall, install a drain made for the membrane then reinstall the flooring

PVC is fine to use going from a 6” floor drain to a 1” pipe is counter productive

A drain made for 2” pvc then pipe to outside using 2” pipe would be better

Btw your water heater can but should never reach temperatures of 200F
The water temperature should never exceed 130F

DITTO

You will need at LEAST 2" piping if you wish to handle the discharge of a T-P Relief Valve.

A 'drip' may be handled by 1" but an actual relief or an actual serious leak will require LARGE piping.


HOWEVER


Caulking the room and/or 1/4 round molding all around with a good door saddle will create a 'shower pan effect' to limit damage from any flooding to that room only (hopefully).

Use hole saws to make the penetration(s) and countersink(s) and simply set a round drain flush with the finished floor.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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have a sheet metal shop make you 2 pans 4 inches deep.
have one for the washer and one for the water heater.

drill the drain holes on site.

use 1 1/2 inch black hose for sump pump kits.
don't worry about the hot water and don't worry about the hose having slight dips in it. it will drain fine.

if you still want a floor drain then use a 4 foot trough drain. adapt the drain connection to fit the same flexible hose you are using for the pans.

or

build a proper utility room with a sloped and PROPERLY MEMBRANED tiled floor and a central floor drain

or

take your chances with "who flung dung and run, Inc." IOW DIY

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

> have a sheet metal shop make you 2 pans 4 inches deep.
> have one for the washer and one for the water heater.

One reason I want a drain over "2 pans with hoses" is because of the strict requirements around piping the TP valve. i.e. it's not supposed to discharge into the drain pan, it needs an air gap, etc.

My primary concern here is just that the (new-ish) water heater will eventually start dripping when the tank rusts out. I'm not expecting a TP discharge or a catastrophic washer failure but a floor drain can help mitigate those events too.

What is a good brand/model for a floor drain with a 5-6" grate?

Quote

..... i.e. it's not supposed to discharge into the drain pan, it needs an air gap, etc. .....

It is also NOT permitted to be installed in such a manner that a full open discharge will cause damage.

You MUST install in such a manner that a FULL DISCHARGE creates little to no damage.



Therein lies the rub .... or the elephant in the room.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

What's a typical compliant retrofit installation look like, then?

if you want plenty of opening to catch water, use a 48 inch trough shower drain.
[www.amazon.com]

heck, you can seal the floor under the washer/dryer and the water heater and use two 48 inch drains right in front.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Maybe I missed something.....

You indicate you have access to underside of laundry room. So why don't you just run a separate T&P drain line from the heater to the outside of the house ?

This should meet code for T&P line.

JR Smith, Zurn, Josam, Sioux Chief all make good floor drains.

In a perfect world as the others have stated you should water proof the floor.....

You could also install water sensors that have alarms and or shut off the water to the offending appliance:

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IMO - Even with a floor drain these devices are worth it. Especially on a 2nd floor laundry room.

They sell ready made drain pans for washing machines...

> why don't you just run a separate T&P drain line from the heater to the outside of the house

It's kind of a nuisance to have to run two drains, but in terms of routing the pipes this might actually be my best option.

As for leak alarms, I do have a bunch of the Zircon 9V ones.

What are the code requirements for the discharge piping from a Temperature-Pressure Relief (TPR) valve at a water heater?


Temperature-Pressure Relief (TPR) valves rarely go off; but, if one does, it’s a big deal. Super-hot and high-pressure water gets released to keep the tank from exploding like a bomb. So, both the International Residential Code (IRC) and the Residential Edition of the Florida Building Code (FBC P2804.6.1) have the following requirements to make sure that there are no obstructions or the possiblity of injury from the scalding water if the valve opens. Here they are outlined below. And, unfortunately, we have an abundance of examples of how not to do it.

1) The discharge pipe cannot be directly connected to the home’s plumbing drainage system, but an air gap located in the same room as the water heater can used to connect to the drainage system. An air gap eliminates the possibility of backflow from the drain into the discharge piping. The photo below shows TPR and catch pan drains that dump into a laundry sink without necessary minimum 1-inch air gap above rim of sink. To read more about it, see our blog post What is an indirect waste receptor?

2) The pipe should not be smaller than the outlet of the valve and must run full-size (no reductions) to the termination.

3) Each TPR valve must have its own discharge piping, not shared with any other devices or equipment. In the example below, an upper pressure relief valve drain (not visible behind vent connector) has been tied into the drain for the lower one.

4) Termination of the discharge piping can be to any of the following:

+the floor
+pan serving the water heater
+a waste receptor
+the outdoors

5) The piping must discharge in a way that does not cause injury or damage. When there is no TPR discharge piping, or it terminates horizontally, anyone unlucky enough to standing in front of the water heater when the valve opens will be severely burned.

6) Must terminate in a location that is readily observable by the occupants of the home. If the water heater thermostat fails to turn off at its temperature setting and continues to heat the water indefinitely, the TPR valve will open and let the overheated water out; but, if the termination of the piping is not readily visible—such as if it is located under the house—the water will continue to drain until the homeowner gets an amazing electric or gas bill and goes searching for the reason. Also, sometimes the valve fails by opening partially and leaking a continuous small stream of hot water, like the one shown below, under an older mobile home..

7) The piping must drain by gravity and not be trapped. A plumbing “trap" is a part of a pipe where water remains in place after gravity has drained the rest of the water. Because this stagnant water could sit for months and possibly drain backwards into the tank if the TPR valve is opened manually and there is no water pressure at the time, introducing bacteria into the tank, the pipe must completely drain by gravity. A trapped TPR dischage pipe is a common defect when a replacement water heater’s TPR valve is lower than the original one, and the installer connects to the exisitng discharge piping at the wall.

8) Termination of the TPR drain pipe cannot be more than 6-inches, or less than two pipe diameters, above the floor, ground, or waster receptor flood rim level. Again, for safety of anyone nearby when it goes off. The example shown below, with the pipe almost touching the floor, will impede the water flow and cause it to splash upwards.

9) Must not have a threaded connection at the end of the piping. Multiple instances of water heater explosions have been caused by a handyman capping the end of a nuisance drip from TPR piping. Threading at the end appears to make it acceptable.

10) No valves or tee-fittings in the piping. Nothing should impede or split the direction of the flow. For some reason, the installer of the water heater shown below decided that the TPR drain piping needed a vent pipe.



11) Pipe should be of approved materials. Copper, glavanized steel, CPVC, and PEX or PE-RT are all approved. PVC is not approved, because it is not rated for transporting hot water.

12) If the discharge piping is PEX or PE-RT tubing, then it must be one nominal size larger than the relief valve outlet. Also, the flexible tubing should be fastened in place.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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In my neck of the woods #4 is wrong on two points -

Can NOT drain into the water heater drain pan. Not that it is not done.

Can NOT drain to the floor. OK to run it outside, into floor sink, mop sink etc.

Only time it can drain to the floor is if water heater is in the garage and heater is located as such that T&P cannot be piped to the outside. This is only allowed on older installations installed before the code changed and required T&P to terminate outside. Not allowed on new construction.

(5) limits said discharge to locations where it would cause no damage





eg. basement with properly pitched concrete floor to floor drain (or garage with pitch to exterior or a drain)

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

"the elephant in the room" - I think there must be strict code about supporting that sort of weight in a laundry room too. 1/4" thick steel plate floor with steel I-beams should suffice. Might be hard to drill the drain holes though.