I've got some research to do. And then to find out what the contractor thinks too. I like to be informed before asking him to work for me - and you all have helped.

__________________
DS
2010 CL550 - Heaven help me but it's beautiful
87 300D a labor of love
11 GLK 350 So far, so good
08 E350 4matic, Love it.
99 E320 too rusted, sold
87 260E Donated to Newgate School
www.Newgateschool.org - check it out.
12 Ford Escape, sold, forgotten
87 300D, sold, what a mistake
06 Passat 2.0T, PITA, sold

Las Vegas NV

FWIW - The two most common alternatives are EPDN ("rubber" membrane - tire tube like material) and modified bitumen (commonly called "modified torch-down) with either a smooth or granulated surface. Either one can be had with a 15 year warranty.

EPDN will require a contractor "licensed" by the manufacturer for the initial installation, as well as for repairs, to maintain the warranty, and from experience I can note that the 15 years is all that can be expected.

We usually spec the modified for ease in finding a contractor that can do an acceptable application and more importantly for longevity. If the modified is coated with an acceptable product, and recoated at regular intervals (every 4-5 years in our climate), it will last a very long time, regardless of the 15 year limited warranty period. We have replaced regularly coated modified roofs that are 40-50 years old, not because they leak, but because they are well beyond their design life, and the Owners are nervous.

Whatever choice you make understand that any roofing material is just that, and will not stand up to pedestrian traffic, or the abrasion from "sleepers" that support a deck.

Good luck,
Jim

__________________
2005 C240 4matic wagon (daily driver)
87 190D - 225K (on loan)
85 190D - 312K (on loan)
2011 Subaru Legacy AWD (Wife's)

The torch down modified bitumen I used, had an additional product to use if you wanted to walk on the roof. It was about 1/4 inch thick and was torched on top of the finished torch down roof. I imagine this would work well under the sleepers for a deck.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

There are pros and cons of building up with a crawlspace and not. With a crawlspace you run the risk of animals getting up there and nesting and creating holes and ruining the rubber. My biggest problem with EPDM (synthetic rubber) is ants. They make nice perfectly round little holes.
Building on top you won't have access to it. The idea of creating the deck in sections isn't a bad idea at all.

When you lay rubber down on something soft and poke it, say you drop a knife, the rubber will stretch and break through. If you lay the rubber down on something hard and drop the knife on it it will hardly effect it. That's why I'm with Tom on the fully adhered. Gluing the membrane down on a hard surface will make it more durable but it will drive up the cost. Plywood is expensive.
It will also make it a lot easier to find a leak, if it ever does.

I like the TPO for a membrane. It's heat welded together and holds up well. It's installed the same way as the EPDM.

I have never been a fan of modified roofs. I see here that people have had success with it but I have never seen one that hasn't leaked.

Danny

__________________
1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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