# Weatherproofing a Wooden Roadbed



## Steamer91 (Oct 13, 2011)

Hi everyone,

I'm currently building a railroad up on steel angle and rebar posts for my first "real" layout, and I have question so far as weatherproofing goes for the wooden boards the track rests on. Right now, all I have in that regard is two coats of good outdoor paint on all the wooden bits, is that enough? Or do I need to put something on top as well before I can lay the track down?

I have been to a friend's railroad, which is virtually identical to what I'm putting in so far as construction methods, and he used a sort of roofing asphalt, then a sort of rubber matting on top of his two layouts he built out the garden as well as painting all the wood, so I'm leaning towards doing that, but I'm looking for something that yields good performance but isn't too expensive, does anybody have any suggestions?

My pike is coming together in Missouri, which means rain, wind, and soon enough, snow, so I definitely think good weatherproofing is in order so I don't have to go tearing the line down and redoing it every year.

Cheers,
Brendan O.


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## FlagstaffLGB (Jul 15, 2012)

Water, temperature changes and freezing temperatures just don't like to mix with wood very well. Paint will eventually peel and once the water gets to the wood itself, then you'll have warping (depending upon the grain of the wood). I'm in Arizona and have used the painted surfaces with asphalt rolled roofing to cover the wood...most of the problem here is UV and heat...but it does the same thing as the wood dries out. Your assembly will work, but probably will need repairs (constantly) after it has been outside for a couple of seasons. If you can laminate 1x3 or 1x4s with the grain opposing each board, it may last longer. Good luck.


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## Trains (Jan 2, 2008)

Brendan,

I use 2x6 cedar outside on the ground for 18 years with no treatment.
Like your Mopac emblem.

Don


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## Scottychaos (Jan 2, 2008)

My advice: dont use wood. It might hold up ok in a desert environment, but for anywhere with real seasons, rain and snow, I wouldnt use it at all..no matter how well you protect it, it will eventually fail and need to be replaced.
much better to use inert materials, plastic, vinyl, aluminum etc.

Scot


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## Amber (Jul 29, 2011)

Trex, or other plastic material porch decking should work well in a wet climate. I don't know how well it would hold up to the UV in the southwest though.


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## armorsmith (Jun 1, 2008)

Brendan,

A bit more information would be helpful, pics would help even more.

You don't say how this assembly is being done, so I will make a few assumptions and you can correct me from there. You say raised on rebar and angle. I would gather that being in Missouri the frost line is somewhere between 24 and 36 inches deep, so I assume your rebar 'posts' are at least that deep or the frost will move them each freeze thaw cycle. You don't elaborate on the attachment of the angle to the rebar, so I am going to assume it is welded. You also don't tell us whether they are 'attachment' angles to connect the wood boards or whether they run post to post. For the discussion I will assume they run post to post. I will also assume that the bottom of the board is some distance above the ground allowing for air flow.

There are may methods of preserving wood in outdoor application. The most important one is to allow the wood to dry after it gets wet. Any area that is 'enclosed' where air flow is limited is going to be subject to premature failure. A good quality exterior oil based enamel house paint, properly applied will last many years, assuming proper drying ability. A good cover of ballast will aid in the longevity in that it will take the bulk of UV damage to the paint out of the equation. (Small side 'boards' to help retain the ballast will help.)

Although I have no personal experience, I have heard of people thinning roofing tar with kerosene and applying multiple coats, works sort of like creosote. The tar is definitely the most UV resistant material I know of. I would assume by the nature of the material that this method would tent to remain a bit tacky for many years. A good cover of ballast would eliminate the sticky part on top.

As for roofing felt or rubber membrane, IMHO these will hasten the decay by trapping moisture between the wood board and paper/membrane.

Amber commented about using Trex. This is a good material for it's intended purpose, provided you properly treat any cut areas. This material is a combination of recycled plastics and saw dust. Once the plastic seal is cut, the wood portion is exposed to the elements, and others have experienced swelling and fast deterioration. I do recommend using an all PVC material primarily sold as trim material for home construction. It can be obtained at most home improvement stores. Cutting does not have a negative affect on the longevity, and custom configurations can be 'made' using the same PVC cement you use on PVC pipe.

Just my tuppence worth.

Bob C.


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## Jerry Barnes (Jan 2, 2008)

There is a good signboard that many have used. Aluminum on both sides with a plastic honeycomb and you can get edge strips. The name slips my mind, but you should look into it. Comes in many colors, or none. Check with your local sign company, or do a search. 4x8 and 4x10 panels, as I recall. My wife used to do a sign business and we ordered it a lot. Cut's easily with a jig saw/sabre saw/router. Here it is:
http://www.laminatorsinc.com/sign-panels/products/alumalite


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## scottemcdonald (Jan 11, 2008)

I'll be using Dibond on my elevated railway. Its the same stuff used for the portable tracks many of my friends use out here in the east. http://www.tri-dee.com/Dibond%20Aluminium%20Composite%20Panels.htm

Scott McD.


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## John J (Dec 29, 2007)

What about Thomson or Barr the Deck Sealers. Will they help?

JJ


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## Jerry Barnes (Jan 2, 2008)

I'd avoid wood.


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## Dan Pantages (Jan 2, 2008)

ABS for the posts, steel studs for the stringers and Dibond for the top.


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## dieseldude (Apr 21, 2009)

Not to hijack this thread but.... Wow Jerry- I wonder if that alumalite stuff would be a good core material for making model buildings- kinda like corroplast? Ever try it?

Ok back to your original thread.


-Kevin.


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## Dan Pantages (Jan 2, 2008)

Kevin, yes it is good for that. Check out this site.

http://www.axom.cz/imgs/articles/18-6_DIBOND___technickUe_manuUol.pdf

It tells you everything you want to know.


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## Jerry Barnes (Jan 2, 2008)

I've used pieces for building roofs, works great. Could be a good base to apply anything to. I've sort of reached the point of not wanting anymore buildings, don't want to over crowd the layout.


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## Steamer91 (Oct 13, 2011)

Well, I'll have to post up some pics to show you how it all works, but for those of you who have run at Larry Herget's big outdoor track in DeSoto, Missouri, it's the same track supports and everything, quite literally, just with new lumber and a new track layout to fit my space.

Mr. Herget was kind enough to let me have about 3/4 of the old layout when he decided to downsize to a smaller pike (thank-you so much if you're reading this, Mr. H, many times thank-you), so I spent about two weeks dismantling and transporting all the parts and pieces home, then the re-build started, and has been going on ever since, and I still have a long way to go before I steam the first train over the line.


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## Bob in Mich (Mar 8, 2008)

Steamer91,I think You are going to find out that a wood top will be very Expenceive.
#1.It will warp and Cup
#2 Dry rot
#3 when this happens Your track will be lumpy and De Raill Trains
Here is what I used and it has lasted 14 and1/2 Yrs so far.You will have to put Money up front first and not have to replace it in 2 to 3 Years from now.Like a Lot of Michigan Live Steamers have done.


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## Steamer91 (Oct 13, 2011)

Well, it's a little late in the game for me to swap materials, I'm afraid, so it's going to have to be made to work with wood, hence my question on what would be a good material to lay over the tops of the boards to help weatherpoof them a bit better.

I should explain that all the boards have a stress-bearing spine running underneath the middle of them, made of 2X6's or 2X4's, which holds the boards rigid and flat, thus mitigating any warping or sagging problems and providing extra support, and like the boards themselves, all the spine pieces have been painted with two coats of exterior grade white paint to help weatherproof 'em.


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## Semper Vaporo (Jan 2, 2008)

I used treated wood for my elevated RR. Mine was just 5.5 inches wide (1 1x6 board). I used two 1x3 stringers under that surface board separated by short pieces of 2x4 boards about every 12 to 16 inches. I used polyurethane glue to attach the 2x4 spreaders to the stringers and in addition put 2 deck screws through each joint. Most of these sections were 3 to 4 ft long and some were longer on one edge than the other so it could be assembled into a curve (17-ft diameter loop backs).

This was all up on 4x4 posts that were just stood on 2-inch thick concrete patio blocks. The supports alternated between one post and two posts to form a stable triangular (3-leg) section. The bottom of the posts had a landscape nail epoxied into a hole I drilled into the end and the concrete blocks had a hole drilled in them to accept the nail... this was to keep the post on the block. The nail did pierce the ground under the block.

Originally, I did nothing to the boards to protect them and the boards did cup and bow with changes in humidity (rain/sun) such that the track was held in a "trough" when cupped (hard sun) and tended to teeter sideways when the board was bowed up in the middle (rain). The track tended to catch on the imperfections of the wood grain when expanding and contracting lengthwise and this caused problems with the joints coming apart.

I then put some plastic landscape edging material along the sides, sticking up about 1/2 inch and poured granite "chicken grit" on the track as ballast and used a paint brush to sweep it along, and then I'd gently shake the track every few feet and the track would "float" to the surface of the ballast. It looked really nice, and eliminated the joint separation problems. I no longer even noticed the cupping and bowing, so I don't know if it continued doing so or if the ballast kept the wood at a more constant moisture content.

I did have to add ballast every year or so because it did blow off and rain would displace it, but I think I lost more to the sparrows that loved eating it (for their gizzard). I didn't mind the birdies consuming it... it was cute to see them, 5 or 6 in a row, hopping down the track like a feathered train, stopping every few feet to eat some more ballast.

Anyway... it lasted quite well for 5 or 6 years with no other problems. Then one winter a huge snowfall left a mound of snow 6 inches tall all along the top of the structure. Right after the snow, it warmed up for a few hours and the snow began to melt and ran down into the joints between the wood where the ends met over the posts. And that evening the temps plunged to below zero and all that water in the joints froze.

I did not get the polyurethane glue spread evenly and it did not foam out to spread as much as I figured it would. Thus there were gaps in those joints that filled with water. The freezing water either snapped the deck screws or pulled the heads through the 1x3 boards. The glue joint did NOT fail... it was the wood behind the glue that failed! One piece would have a 1/4 in deep 2x3 inch "pock mark" and the mating piece would have a 1/4 tall 2x3 inch "wart" on it.

I reassembled the joints and tried to seal them with silicone caulking compound, but that did not stick well to the wood and still let water in and the next winter it all happened again! This time I gave up on repairing it. I removed the track and cut up the whole thing and it went to the city dump.

I now have been given several tables that were built to assemble a track on for display at garden shows and other meets. The tops are some sort of particle board that has been painted with what appears to be an epoxy paint. I don't think it was designed to be in the weather, but it was stored in a back yard on edge with a plastic tarp over the lot. The tarp leaked a lot and there was mold and mushrooms growing on the underside of the table tops (and a few wasp's nests), but it still seems to be structurally sound.

I looked into using roll roofing to cover the tops, but the expense of 3 rolls was more than I felt like spending and I didn't like the idea of trying to wrap it over the edges, nor the possibility that the tar impregnation would rub off on clothing (or children's hands) if someone were to bump up against it on a hot day.

My son works for a boat sales and service shop (pontoon and other pleasure craft) and in the fall they cover customers boats with a shrink-wrap plastic. As an experiment, he made a PVC pipe frame for a 10x16-ft. storage shed and used a couple of large scraps of the material to cover it (roof, sides and ends) and then heat shrank it on using a torch made for that purpose. He then attached a zippered door (supplied for getting into a covered boat) to the end and cut away the material he had shrunk on the shed behind where the zippered door was applied. This shed has withstood one North Dakota winter and one summer so far. The snow load did deform the PVC pipes a bit, but did not collapse the plastic... mostly the snow just slid off the gabled roof.

He has given me a large sheet of this material to see if covering the tables will weatherproof them. I have not put the material on yet and unfortunately probably won't get to it until next spring, but I offer the possibility that you might look into using something similar. It is expensive material, but I got it for free.

At the very least, my story should tell you to worry about the joints between the boards more than the surfaces.


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## Steamer91 (Oct 13, 2011)

Okay guys, here's some photos of my track to give you an idea of how everything goes together, with apologies for the delay, haven't had the time to grab a picture for a while, but I had some time on my hands today.

Thanks for all the great input so far!


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