We are gearing up for restoration of our newly acquired N6B. I know many groups have restored wood cars and have a question about roofing material used.

The original specs call for an asphaltum base material, but the previous owners just nailed roll roofing over the wood and then patched cracks with roofing tar.

We are looking for something that will last longer, especially since the car will not be under cover...at least not in the near future.

I've been looking at the rubber membrane type material, but am wondering how many groups have experience with this material. Is it good for the top layer or a sub material? Does it hold up well when exposed to the elements? How is simple or difficult is it to work with?

Thanks
Bill

Check in with the Strasburg Railroad. They are using a rubber membrane with a great deal of success (at least the last time I heard) that imitated a canvas roof, while providing modern durablilty

Also, get hold of Bill Kepner with the Friends of the C&TS. His crew recently finished a resuscitation of a wood caboose that included an exhaustive look at the options available for roofing.

JAC

I installed a rubber roof on a streetcar 18 years ago. It is now out of service being rebuilt mechanically at Gomaco, but in the 18 years of use in between there was never a roof failure. I would encourage you to use rubber roofing.

I'd want to also assure that the substrate was pretty devoid of protrusions (such as corners of boards) that could eventually wear through points of contact as the cars elements move in service. If it will just be standing still, not so much a worry.

Should a projectile penetrate the roof, just glue on a patch using the same material and the proprietary adhesive and you are good to go. Couldn't be easier.

dave

We are preparing to restore an N6B as well and in the name of authenticity will be using coated canvas which is what they originally used.
From our research we found that they would just go up there every so often and put another coat of tar on it. But if longevity is your primary concern, then a rubber membrane roof is the way to go.

Later!
Mr. Ed

Ed,

Is yours going to under cover?

Bill

That should read "Is yours going to be under cover". :)

Bill

Did they really use tar as the canvas coating material? Haven't run across that application before, just linseed oil or similarly based canvas roof paints. I now use Hanry latex based roof coating as the bedding / coating material for any canvas I am required to use, which can be overpainted with custom tinted latex color coats for an authentic appearance.

dave

hytwr1-No, we don't have any cover. All of our rolling stock is outside. We had hopes of having some cover to do the restorations if we could have gotten the old rail yard next door but wawa beat us to it. In that yard are several long buildings at the back of the yard that we could have put doors and stored up to ten cars depending on car length.

Dave-I just presumed it was roofing tar since that is what we scrapped off of the N5C. The roof on the N6B was sitting inside the car where it collapsed along with several feet of the wall. It was covered with roofing paper. We did manage to save half of the cupola.

Later!
Mr. Ed

I've certainly seen enough "tarred" canvas over the years, mostly on steam railroad equipment. The cab roof on Soo Line 2-8-2 1011 sitting in the park in Ladysmith, WI has so much tar on it that it looks like a frosted cake.

Passenger and electric railway equipment seemed to fare a little better, but I distinctly remember IRM's 900 series Milwaukee streetcars had their roofs mopped with tar.

Tar is actually likely a misnomer; the material is most likely "car cement" which was a heavy asphalt paint, similar to what used to be used for automobile undercoating. A modern day equivalent might be mobile home roof coating, except without the aluminum pigment. Lots of railroads seemed to specify this material on underframes and steel freight car ends, as it was somewhat resilient and resistant to abrasion from stone chips, and on steel car roofs, since it would seep into any cracks and crevices and keep them watertight. I don't know if anybody was specifying this stuff on brand new canvas, but I can certainly see the RIP track foreman telling the guys to mop a coat on Conductor Jake's caboose to stop him from complaining about leaks in his roof.

As part of a Boy Scout project during the 1970's I helped spread something tar-like the roof of 5012 at ORM in Worthington, OH. Really would not surprise me if that layer of tar is still the top coat.

Bob Bunge

Well, a canvas roof does require some maintenance. In our experience that means recoating with the same linseed oil based special canvas paint not tar. True, companies in decline often resorted to mopping or troweling on asphalt or tar, but that was very destructive to the canvas roof structure - perhaps due to differing rates of expansion due to temperature.

It is often forgotten that canvas CAN be a very serviceable roof, and was even applied to house roofs in some parts of the country.

Bob Kutella

Thanks for all the info.

Bill