The local lumber yard has a PVC type material for trim boards. Its available in the standard 1x sizes, and its UV protected, and all that. I have a couple pieces of it that have been outside for a year now and no sign of yellowing, cracking, or anything.
Bob,
Nice to hear. 
I’m reasonably sure that there are successful applications of PVC that are similar to what I intend, we just haven’t heard about them, yet.
Mike, would you mind not referring to Plexiglas or Perspex? I do not believe anyone has said they are using them, and they definitely are not for outdoor use, and they are not PVC.
They are not for outdoor use, and not what Hans is talking about.
OK, Don’t know about the UK, but PVC is used for many outdoor products. Maybe you are having thin sheets warp from heat… do not think that is characteristic of pvc alone, but any thin material if there is a high heat gradient.
(I’m not a chemist, but I have a degree in applied Physics)
Here, PVC is used for conduit, sprinkler pipes, and other stuff.
I do follow what you are saying, that moisture can collect around it and without drainage, ice buildup can cause damage. Again, it’s not PVC that’s the problem here, but lack of drainage… you could get the same with a sheet of plywood under the switch, or a sheet of steel, or a sheet of Saran Wrap.
I think your point about drainage is the most operative, letting the water drain away.
Regards, Greg
I found out about it when we had a new sliding door put in, and the contractor put up a couple pieces as temporary trim. I talked to him about it and he said he’s been using it for years.
Greg ,
Please look at replies 6 and 7 above .
Mike
When you have done that , consider what I said about water “beading” . Simple holes in whatever substrate are not going to drain beads , whose characteristic is to stay where formed . I am going by experience here , irrespective of technical qualification . I have had a lot of experience in material application, both professionally and as a hobby . I used environmental test facilities to test quite a few possibilities for outdoor work on my rail stuff dating back to 1966 , using the extended life cycle facilities which were available to me .
When I post on this site something that is useful to know , I do it in the hope that people can avoid the learning curve that prior experience could avoid .
It is there for anyone to use as they see fit .
Mike Morgan said:
...................................................When I post on this site something that is useful to know , I do it in the hope that people can avoid the learning curve that prior experience could avoid .
It is there for anyone to use as they see fit .
Mike,
For that reason I tested the PVC first, including using different adhesives for the ties. Testing things first accounts in large part to the slow progress on the outdoor portion.
Hans-Joerg Mueller said:
Mike,For that reason I tested the PVC first, including using different adhesives for the ties. Testing things first accounts in large part to the slow progress on the outdoor portion.
Not me. I just throw stuff on the ground and see what sticks. The “Just Do-It” philosophy. I’ve been running trains and re-building the layout for 5 years. Not knocking anyone sharing their experience, I’ve used lots of what I learned in the forums, so please do keep enlightening us.
HJ - One more question about the paper template. I know how and why you use it. The question is what happens to the paper after the turnout has been in the weather for weeks, months or years? Do you strip off the paper or does it crumble off and become one with the ballast? Should anyone even care?
JR
Jon ,
In a word , yes . And , yes , your philosophy is one way to get fun out of things .
However ,
In general , I would say the following
If the paper gets wet and freezes , it MAY push your track out of line . My experience dictates that I would not risk it , a set of points is not easily thrown together , and risk of damage by any cause should be avoided .
If it never freezes where your layout is , we have to assume that it may get rather hot , in which case I can vouch for serious bending of rails due
to expansion . Not only of the rails but also expansion of the substrate . Differential expansion .
I have to assume that we are not all physicists , so I will explain what this means .
The rail assembly and its substrate expand at different rates , thus throwing stress onto both . No argument , that is a physical fact . OK , someone
will now say “yes but only by …” and quote fractions of millimetres , or even old fashioned inches . I regret to say that the materials
involved don’t give a toss , they ultimately break . It’s called “stress” . Stress fractures are what kill aircraft passengers occasionally .
Now , if you want to risk it , fine , be adventurous . But I would favour the use of treated wood IF I used a substrate at all —I don’t—treated
wood is cheap , predictable , takes fasteners easily , and if you are really good at making your points in the first place , allows you to de-mount
the assembly and set it on ballast like wot the reel blokes do . Ballast has worked since , oh , eighteen canteen , so why re-invent the wheel ?
I have no argument with experiment . Enjoy yourselves . Just remember that this site is a means of disseminating experience gained . If the
experience does not accord with your precepts , why bother with it ?
Mike , vmtic.
PS , just who is the manufacturer that guarantees PVC to be dimensionally stable ? Think about what it is sold for . If it’s so good , why do they
not make outdoor trains out of it ?
Jon Radder said:
............................HJ - One more question about the paper template. I know how and why you use it. The question is what happens to the paper after the turnout has been in the weather for weeks, months or years? Do you strip off the paper or does it crumble off and become one with the ballast? Should anyone even care?
JR
Jon,
The paper gradually crumbles away, smack up to the bead of adhesive which I always have around the ties - comes from using plenty of the Weldbond.
As for PVC, I’m not too sure that it molds detail very well in an injection type molder. That may explain why they don’t use it in models…but I’m not sure on that. But what I do know is that it is used extensively in this part of the woods for lots of outdoor stuff…including exterior molding on homes, kids outside playsets, lawn chairs and furniture etc. as well as plumbing pipe (In ground as well as in wall) and other construction uses. It’s been used successfully in ladder type construction on layouts. It’s been successfully used as posts for raised bed layouts. The plumbing pipe has been used in a different type of subroadbed successfully. I have never heard of anyone complain about expansion, deterioraton, discoloring or any other problem.
There is another product available here that’s been good for under turnouts and it’s a concrete product called backer board. It’s easy to cut, stable, and holds up well in moisture.
Warren
Jon,
What tiny amount of paper would “crumble off and become one with the ballast,” is slow to deteriroate and would need a microscope to detect. It wood (sic) 
return to its pulp state once wet, and then dry as wood fibers.
My discomfort with the whole idea is that the paper in the bond creates a weak point and could easily fail. HJ has five years experience that says it ain’t gonna happen. Mike says that using dissimiliar materials in the bond will create stress fractures. I didn’t think of that, but I see his point and that gives me discomfort, too. HJ, on the other hand, seems to say that his 5 years of experience indicate that stress fractures in his climate is not a problem.
It seems that the only way to know for sure is to build an example of each idea, put it in the ground and see which lasts the longest. Probably by that time I’ll be too old to use the information in any substantial way.
I know that Jens Bang has turnouts that lasted for 10 years in the ground sitting on top of 1.5 inch steel angle iron. They started to fail because the frost-heave started causeing the spikes to back out of the redwood he used for ties (sleepers).
SteveF
To anyone who is really interested in practicalities .
I tried the same as Hans in practise , and in an environmental chamber . It failed in both cases .
Now , frankly , I do not give a toss what happens to anyone else’s stuff . I just try to advise . It upsets people sometimes when advice goes contrary to beliefs .
It just ain’t gonna happen to me . I join this site every day in the hope that I will learn something new . I am 69 . I do not know it all . I try to help.
If my experiences run contrary to theories , tough .
I have been caught out too . But not twice by the same thing .
Paper over your whole layout if it suits , use plastic when wood will do , I don’t give a shot .
But if you wish to argue , come up with cogent facts .
And just have a little think----what would I gain by giving bad advice ?
Steve Featherkile said:
I know that Jens Bang has turnouts that lasted for 10 years in the ground sitting on top of 1.5 inch steel angle iron. They started to fail because the frost-heave started causeing the spikes to back out of the redwood he used for ties (sleepers).SteveF
Steve,
As soon as I read the GR article on Jens’ layout I said “YES, that’s how I’m gonna fasten the prefab track.” 
Mike,
Thank you for your effort. As I mentioned I’ll post the longterm experience.
BTW would you believe that the “crazy” concrete and stucco people in this country actually add Weldbond to the respective material? I have a few cement/concrete/stucco projects (all of them GRR related) on the back burner. I’ll be using Weldbond to prevent separation cracking and all the other stuff. As the name indicates “Weldbond” might as well be welded! No, I haven’t done a shear test on the adhesive bond, but knowing RedCedar I’d say it will split right beside the bond, when lots of direct force is applied.
Hans ,
The best of luck with your experimenting , let us know how you get on .
Mike
I ike the cemet backer board, you can get it in 3/8" thickness and remains stable in all kinds of weather.
The Llagas Code215 NS profile arrived yesterday, may the fun begin.
Dad used plexiglass under the switches he built 26 years ago, and they’re still as solid as they were way back then. Now, I can’t say with any certainty that the ties are still physically attached to the plexi, but the switches certainly haven’t moved anywhere. On the larger switches (the double-slip switches, etc) he drilled the occasional hole for water drainage.
I used wood battens under the switches I built for my last railroad.
Later,
K