shower pan

[Steve Howell]

I am a termite inspector in California.
State regulations mandate that we plug the drains of stall showers, fill the base to within one inch of the top of dam for a minimum of 15 minutes, and recommend repairs should leaking be found.
Are there any current plumbing or building codes that in fact requires that the water proof membrane be installed so that no leakage would occur during this test.

specifically, could a membrane extend over the rough dam, and then the shower be legally be built up with mortar and tile to say two inches above the pan membrane?

Thanks for your thoughts and references.

[Jim Luttrall]

P2709.2 Lining required.

The adjoiningwalls and floor framing
enclosing on-site built-up shower receptors shall be lined
with sheet lead, copper or a plastic liner material that complies
with ASTM D 4068 or ASTM D 4551. The lining material
shall extend not less than 3 inches (76 mm) beyond or around
the rough jambs and not less than 3 inches (76 mm) above finished
thresholds. Hot mopping shall be permitted in accordance
with Section P2709.2.3.

Here is the applicable national standard but CA may be different.
Also, check out this thread:
http://www.inspectionnews.net/home_inspection/plumbing-system-home-inspection-commercial-inspection/15782-leak-test.html

A useful function here is the search which will answer many questions since most everything has been discussed in the past.

[Door Guy]

You would be defeating much of the purpose of the pan if you build the floor above the panning material. Notice code requires it to extend up 3 inches beyond the floor. So if the floor is above the panning, water can leak through the walls rendering the pan useless.

[Michael Thomas]

Are there any current plumbing or building codes that in fact requires that the water proof membrane be installed so that no leakage would occur during this test....


The liner manufacturers require water testing once the liner has been installed and before the mortar bed above the liner is poured, the Oatey instructions are typical:

http://paragoninspects.com/articles/images/articles/shower-pan-leaks/water-test-oatey.jpg


specifically, could a membrane extend over the rough dam, and then the shower be legally be built up with mortar and tile to say two inches above the pan membrane?


As long as the top surface of the tiled shower floor is the minimum required distance below the curb,and the liner extends the minimum required distance above the curb, this would be the normal method of construction for a tiled shower pan, see for example Diagram 1 here:

Tiled Shower Pan Leak Detection, Investigation and Repair FAQ – Paragon Inspections Chicago (http://paragoninspects.com/articles/pdfs/plumbing/fixtuers/showers/shower-pan-leak-faq.pdf)

[Mitchell Toelle]

Any pan leak test requires that the drain line be blocked below the weep holes in the drain flange, not just capped or covered at the surface. You should get one of those inflatable drain blocks that plumbers use, remove the drain grill, insert the inflatable block and inflate it. If you just cap the drain, water permiates through the tile and mortarbed and weeps through the weep holes, thus allowing the water level to drop and gives a false test.

IMO, a test needs to be for 24 hours or it's not a real test. I understand that your requirements are for less time, but that 15 min. test is really of very little use and can subject you to greater liability. I have called for long pan tests on many showers, where the Pest/ Termite Inspector already did their short test and found nothing, only to find that the pan did, indeed, leak.

I will do them for my Client for an extra fee, but I usually just recommend that a licensed Plumber be used. All of the pans I have referred have shown other indications of past leaking (some very minor looking) which raised my suspicions in the first place.

[Mitchell Toelle]

BTW Michael, good link post. Nice pics and graphics. IMO, most HI's don't know or understand how pans are constructed. For those, this link helps greatly.

[Michael Thomas]

Any pan leak test requires that the drain line be blocked below the weep holes in the drain flange, not just capped or covered at the surface. You should get one of those inflatable drain blocks that plumbers use, remove the drain grill, insert the inflatable block and inflate it. If you just cap the drain, water permiates through the tile and mortarbed and weeps through the weep holes, thus allowing the water level to drop and gives a false test.

IMO, a test needs to be for 24 hours or it's not a real test. I understand that your requirements are for less time, but that 15 min. test is really of very little use and can subject you to greater liability. I have called for long pan tests on many showers, where the Pest/ Termite Inspector already did their short test and found nothing, only to find that the pan did, indeed, leak.

I will do them for my Client for an extra fee, but I usually just recommend that a licensed Plumber be used. All of the pans I have referred have shown other indications of past leaking (some very minor looking) which raised my suspicions in the first place.

Agreed.

When testing pans to identify leak sources (this is a separate service, not part of a standard home inspection):

1) I use a weighed flange with the required length nipple and a rubber stopper to prevent splash-back to introduce water below the liner drain point to test for plumbing leaks.

2) Then use an inflatable drain plug to test the liner drain.

At home inspections, I use a flanged stopper along with a water level alarm, to allow an extended test while I perform other parts of the inspection.

I've never been much worried that this sort of testing increases my liability as:

1) IMO, I'm a lot less likely to get sued over the leak I found than the one I didn't even try to find.

2) My client has seen me try to find a leak, and likely understands that (as I explain) "It's hard to prove a negative, and there is no way to determine that there is NOT a leak, and a slow leak could take days or weeks to show up after you move in. But we tried hard to find one in the time available".

[Michael Thomas]

BTW Michael, good link post. Nice pics and graphics. IMO, most HI's don't know or understand how pans are constructed. For those, this link helps greatly.

Yup - these is a lot of information out there, but not in any one place. When I was first trying to understand these issues, and educate myself about them, I ended up posting a pretty lengthy diatribe about my frustration with testing, and sellers, and buyers.... and, well, the whole issue, over on John Bridge's forum:

Testing standards for showers - Ceramic Tile Advice Forums - John Bridge Ceramic Tile (http://www.johnbridge.com/vbulletin/showthread.php?t=65312)

[Michael Thomas]

There is also this:

Inspecting Tiled Showers and Shower Pans | ASHI Reporter (http://www.ashireporter.org/articles/articles.aspx?id=609)