I’m thinking about constructing a showerpan like the one described by Tom Meehan in FHB 141. He recommends using a specific vinyl membrane as the water proof membrane. I have some EDPM left over from a roofing job and wonder if anyone has thoughts on whether it would work as well. It’s pretty rugged stuff, and I expect it would hold up quite well.
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The correct product is cheap enough to buy.
Why take the chance.
However, if you'd like to experiment, have at it.
Get back to us with the results.
Eric
I Love A Hand That Meets My Own,
With A Hold That Causes Some Sensation.
If you use the product from the Noble Co., make sure you buy a tube of their special sealer. The trick with EPDM might be a proper seal to the drain.
Non-traditional pan membranes can be OK I guess. The questions I have for the EPDM manufactuer are: (1) Will they warranty the application as a shower pan membrane; (2) Is it certified to inhibit mold and fungus and have proprietory moldicides and fungicides within the product? (3) Does your local building code allow the product?
Our City Code only allows PVC/CPE pans and Hot Mop. Period. However, I have seen torch on roofing, Ice and Water Shield and EPDM. Doesn't mean its right, but I have seen it. Our Inspectors wouldn't approve it. So you have to lie to your customer that it was inspected. If this is your home, do you have to disclose when you sell the home that you didn't have a legal shower? Here, state laws require such disclosure and you can get sued if you lie or omit critical facts.
If this is a job for you, I will say you are saving about $100 in materials for the pan. Is the risk and exposure worth the $100? Wouldn't be for me. By square footage, the shower is the most expensive room in the home. One minor screw up, like clogged weep holes can make a $8,000 shower worthless. Are you willing to take that risk?
If this is your home, then ask yourself the same questions whether you'd be willing to tear out a month's work for $100 worth of savings.
I wouldn't. Use an approved pan. And don't follow Mehan's article--he uses CBU on the curb and nails right through the pan membrane. That curb will leak like a sieve. He then covers the whole mess up with trowel on waterproofing. He should have built a mortar curb. There are other mistakes as well.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
I built my shower pan last year and the membrane and sealant only cost me a total of $80.00. I don't think EPDM could really be much cheaper than that. One other thing that occurred to me is that the membrane does not need to be tough. The mortar bed and tile take care of that. It needs to be easy to work with, durable, warranteed for the application, legal, and resistant to lots of bad microbes and fungi.Les Barrett Quality Construction
Thanks Boris, Les and the rest.
The pan is for my own home and a home I only want to build once, so scratch the EPDM idea. What I'm really interested in is a shower base that can be tiled over so that we have a tiled floor in the shower. Can you recommend a manufacturer that makes a pan or some precast product for this purpose. One local bath plumbing outlet here had no idea, the other major outlet is looking.
Alex
I'm using a Swanstone base for a bathroom that I'm building, 3x4 ft, quite nice. Corian-like material. With matching vanity sink. I know this part of the project will have the biggest chance of not failing/leaking. I still have enough tiling to do and be creative with the rest of the shower and bath.
Go to the Noble Company web site. The have a number of products to simplify and enhance tiling. They have some material that will put the proper slope under the membrane. Putting the mud base on top of that is relatively simple. Make sure the weep holes stay clear. In my shower, I also tiled a drying area and put electric heat from Suntouch under the tile. This makes a huge difference in the winter as you do not have to stand on cold tile.Les Barrett Quality Construction
Alex.
Take it from someone who made good buck's fixing other people mistake's for many year's. Get the right stuff. The first problem that I see is the roofing ""membrane"" is to thick to be fold the right way.
Good luck.