Home-made Water Heater Pan

[BN4537]

I occasionally run into the situation where someone is trying to replace an older water heater that was installed originally without a pan in a confined space. The new water heater will barely fit in the space, but the plumbers tell me that they can't find a pan that will fit into the space under the water heater - they are saying they have a 19" space and the smallest pan they are finding around here is a 20". 18" pans are available online, but really they are too small for the water heater in question.

The code allows galvanized steel or aluminum not less than .0236 in. thick, plastic not less than .036 in thickness, or "other approved materials" (IRC P2801.6).

What would you guys accept as a home-made water heater pan? Is there a shower lining material that would work? Field bent sheet metal pan? What is the easiest solution?

 

[north star]

$ ! $ ! $

1st, ...personally, I would not accept a shower lining material of any
type, for any type of installation method.

2nd, ...forget about what is easiest........Disconnect the water heater,
raise it up and have a drip pan that is sized large enough to handle
a rupturing of the water heater, or other types of leaks and that will
adequately discharge the water to an approved location without
spilling over to the framing \ other.

IMO, the idea of "what is easiest" is not in the best interest of the
owner \ renter or the structure itself.

$ ! $ ! $

 

[Keystone]

Field bend a pan to fit snug in the space. (Metal) I’d accept what was reasonable and water tight from the materials listed in code.

 

[mtlogcabin]

What is the easiest solution?

Hire a sheet metal worker to make the pan. They custom make auxiliary drain pans to hang under HVAC units all the time.
You did not mention anything about the pan drain and if you can even drain it.

 

[BN4537]

For context:

A plumbing/mechanical contractor called me this morning and described an existing mechanical closet in a garage where the water heater was on a platform made of framing and OSB to meet the ignition height requirements. There was no pan or drain existing. There was no extra room, only a 19" space to install the water heater in. I told him to bend a rectangular pan out of sheet metal and seal the corners. He said he would do that, and he also said he would drill a hole in the OSB and run the discharge pipe down to discharge on the concrete floor, so the pan would only have to deal with condensation and leakage from the water heater itself. Since no drain was existing, only a pan was required to be installed.

 

[BN4537]

Now, about using a shower liner, for example the Schluter Kerdi Waterproofing Membrane. Is the issue about flame spread? Lack of watertightness? What wouldn't you be comfortable with?

 

[mtlogcabin]

Since no drain was existing, only a pan was required to be installed.

I did not realize that


504.7.2 Pan drain termination.
The pan drain shall extend full size and terminate over a suitably located indirect waste receptor or floor drain or extend to the exterior of the building and terminate not less than 6 inches (152 mm) and not more than 24 inches (610 mm) above the adjacent ground surface. Where a pan drain was not previously installed, a pan drain shall not be required for a replacement water heater installation.

 

[ICE]

I did not realize that


504.7.2 Pan drain termination.
The pan drain shall extend full size and terminate over a suitably located indirect waste receptor or floor drain or extend to the exterior of the building and terminate not less than 6 inches (152 mm) and not more than 24 inches (610 mm) above the adjacent ground surface. Where a pan drain was not previously installed, a pan drain shall not be required for a replacement water heater installation.

California code does not have that section. You have to wonder what good a pan would be with no drain....well I suppose a slight leak might allow the water to evaporate before the pan runs over but even that seems unlikely. Next is the 6" to 24" termination.....the water should be cooled by the time it gets to the outside and it was never steam.

California code states that the pan shall drain toi an approved location. If the water heater is in a garage, I could allow the pan to drain to the garage floor.

 

[mtlogcabin]

Ice
I am under the UPC also. Our approved location for the drain to terminate is the garage because of our winters and they can no longer be installed in a crawl space (state amendment)

 

[patrickjames]

504.7 Required Pan

Where a storage tank-type water heater or a hot water storage tank is installed in a location where water leakage from the tank will cause damage, the tank shall be installed in a pan constructed of one of the following:

1. Galvanized steel or aluminum of not less than 0.0236 inch (0.6010 mm) in thickness.
2. Plastic not less than 0.036 inch (0.9 mm) in thickness.
3. Other approved materials.

A plastic pan shall not be installed beneath a gas-fired water heater.


504.7.1 Pan Size and Drain

The pan shall be not less than 11/2 inches (38 mm) in depth and shall be of sufficient size and shape to receive all dripping or condensate from the tank or water heater. The pan shall be drained by an indirect waste pipe having a diameter of not less than 3/4 inch (19 mm). Piping for safety pan drains shall be of those materials listed in Table 605.4.

504.7.2 Pan Drain Termination

The pan drain shall extend full size and terminate over a suitably located indirect waste receptor or floor drain or extend to the exterior of the building and terminate not less than 6 inches (152 mm) and not more than 24 inches (610 mm) above the adjacent ground surface. Where a pan drain was not previously installed, a pan drain shall not be required for a replacement water heater installation.