RMNE's shop volunteers have been working on rebuilding the wood/canvas roof of CNR heavyweight coach 4992. The deteriorated canvas and wood tackboards were removed, the wood roof structure was repaired as needed, new tackboards made to original dimensions (both upper and lower tackboards), the clerestory sides were sheathed in new wood and all wood surfaces were coated with polyurethane sealer.

The final phase, application of the new EPDM roof membrane material, started on Saturday January 7.

Photos show some of the steps in the work so far:
Stripping of old roof material at start of work.


Wood roof deck after removal of old canvas.

Wood deck repair under way.



More photos to follow.

Howard P.

More photos:

New tackboard applied to car side. The hex bolts were used for fit-up only; countersunk screws were the fasteners used for final application. All tackboards were painted black before applying to the car.

Repair of the north end curved hood is well along.

Wood consolidant (Abatron) was used wherever possible.


Howard P.

More:

Applying the membrane adhesive (the white stuff) to the wood deck and cleaning the undersideof the EPDM membrane before laying it out onto the wet adhesive. We used a water-based adhesive to allow a few minutes working time to properly place the EPDM membrane.


Setting the EPDM membrane onto the lower deck and clerestory side.


No, we didn't use Naugahyde..... The bottom edge of the EPDM was nailed into the tackboard using copper ribbed shank roofing nails (just like CNR used). There will be a final trim of the lower edge after the work is completed.



This is RMNE's first foray into using EPDM for a passenger car roof, and we are pleased by the application process so far. It almost seems a shame to cover all that nice wood work, though.

Howard P.

If there wasn't a better reason for me to envy all the work you guys have put into that coach, I don't know what is. Stupid question however, but when I was there about two years ago, one of the end coaches had the interior mostly finished, with the clesteroy style ceiling restored on the interior. I can't remember which coach was which, but is 4992 the coach I'm describing?

Howard -

How does EPDM work on the compound curves of an arch roof car or the bonnet of a deck roof? Can the membrane be painted?

Wesley

CNR 4992 was the first full "new roof" that we've applied, because it needed major attention and lives outside. No more patching was the decision. The other car mentioned is CNR 5805, which is in the middle of a l-o-n-g restoration; the interior is about 60% along, and there has been extensive steel work done on the carbody.

As for the curved end areas, with the many compound curves, we plan to follow what was done with the canvas-- some stretching and some seaming. That part of the work will be done after the long parts (lower decks and upper deck) are applied.

We are not planning to paint the EPDM membrane. A previous application of that material to a caboose roof was painted at the edges (CNR orange) because the canvas on that car's roof had been done that way. We'll see how that holds up over the next few years.

Howard P.

Q: Is "Wood consolidant" a $10 word for "glue"? If not, describe its function/role.

Howard,

How flexiable/plyable is the EPDM roof material? How did it compare with canvas by applying it to the compound curves of the roof body?

http://www.abatron.com/building-and-res ... l?vmcchk=1

http://www.abatron.com/building-and-res ... dwood.html

This stuff seems to be the "gold standard" for dealing with punky wood. We have used it on our Thomaston station work, and it has been discussed here on RyPN by others.

Wood glue was also used where applicable, along with lots of screws.

As for comparison to canvas, we did not consider canvas as a option. This car will not have the luxury of living under a roof, unfortunately, and replacing a canvas roof every 8-10 years is not something we want to do. Strasburg uses this material and their wood cars look wonderful, and they have had long-lasting success with the EPDM. We're just copy-cats.

The end hoods are going to be interesting. It is possible that we may use a considerable supply of authentic railroad shop language in dealing with them. Photos will be posted here.

Howard P.

Even the "easiest" canvas roof installs usually require quite a bit of authentic railroad shop language.

This should also be a lesson on always replace the tack molding. Randall Hicks of IRM, who posts here on occasion is a big proponet of this, as he has participated in more than his fair share of canvas roof replacements.

This past weekend, I viewed a canvas roof job I participated on about 4 years ago. We didn't replace all of the tack molding, and the part we didn't replace has began to split and will eventually allow the roofing material to pull away, negating all of that hard work.

Howard,

Would you please share any specifics you can on the EPDM material itself (manufacturer, thickness, cost, etc.) and the application products as well? I am going to be facing the roof covering installation on Buffalo, Rochester & Pittsburgh caboose #280 at the Rochester & Genesee Valley Railroad Museum in the coming year and would welcome the info. The #280 is a wood on steel frame caboose with the roof being comprised of 3" tongue&groove wood. We have replaced all of the wood on one portion of the roof and are working on repairs to the other two so we are growing closer to being able to finish it off with a covering.

When it entered our shop, it had a canvas roof installed by the B&O. Like your passenger car, however, it will not have the immediate benefit of indoor storage once it is complete. We have gone back and forth on EPDM vs. canvas roofing materials. The decision is not final, but having the information would be helpful in making it.

Thanks!

-Chris Hauf

Good thread...both educational and inspirational.

The guy who is restoring the Yosemite Valley 330 used EPDM rubber on the roof, and it looks great. I know he had both discussion and pix... I don't have time to ferret them out, but here is his web site:

http://www.yv330.com/

Ahh, now I see the installation fun I missed! I did get to inspect it on Sunday and it really does look great in person and the EPDM has an elasticity to it that will allow it to flex with the car movement and temperature changes.

The other thing I heard is that while the glue has a decent working time it still has enough tack to it that the material didn't slide or want to creep off the edge of the roof, something that is of concerm with the curved roofs.

Chris,

The EPDM we used is .060" thick. It was sourced locally, from a building /roofing supplier. I don't recall the name of the manufacturer. The same source supplied the adhesive, the cleaner and the other accessories needed, including some seaming/splicing "tape", etc. The stuff was in a 15-foot wide roll and was 90 or 100 feet long and HEAVY!! We set up a way to slit the membrane in three 5-ft wide sections before application.

Check with a supply house in your area and I'm sure thay can set you up with everything you need.

As for caboose roof application, I am posting some photos showing the CV 4014 caboose roof work.

Howard P.