Roadway surface idea

[ctown2 (Craig Townsend)]

So I have a few major roadway surfaces on my layout, including a few feet of rather large sections (4x8).

My plan for tackling this is to use a combination of 1.5" insulation foam screwed down to my framework and then slim coat the top with some concrete resurfacing for a smooth roadway surface.

Does this sound like a plausible idea? Has anyone else done this before?

Here’s a test area that I used concrete patch filler on. But based on the volume I’ll need, I think a 40/50 pound bag of concrete resurfacing is probably a better shot. I’ll have to make a mold edge and just pour.

[rmccown-admin (Bob McCown (Admin))]

I’d use either concrete surfacer or non shrinking grout. Maybe embed some window screen for stability.

[ctown2 (Craig Townsend)]

I was thinking something for stability as well. I’ve got some hardware cloth on hand.
I don’t want it too thick but I also know to thin and it will crack easier.

The interesting thing about the patch filler is that it has resin/fiberglass? strands to prevent cracking.

I might go buy a bag or 2 of resurfacing concrete today and see how it looks.

[Bob_Cope (Curmudgeon at Large)]

Another issue you will have to deal with is the differential expansion and contraction between the foam board and the dried concrete material. I believe that over time the concrete will ‘float’ on the foam board as the adhesion between the two will have gone away.

Might consider doing smaller areas with deliberate expansion joints to help mitigate the differential and make it not so noticeable over time.

[Rooster]

Well if you would like my thoughts on it or even if you don’t I’m gonna tell you anyway!

You did not specify whether you wanted concrete, dirt or asphalt roadways so why not just paint (latex) the 1.5" foam a base color of your choice. You could mask off and paint roadways,highways, no clover leaf interchanges though. Then decide how to proceed from there.

Just a thought instead of worrying about expansion joints or the bag of concrete left out that you didn’t finish off before dinner and then it rains that night.

[Cliff_Jennings]

In view of your impending time crunch, and keeping things simple, I’d have to agree with Rooster in regards to using paint.

You can add sand to the paint for roadways. And for non-road spaces, earth-tones of paint, sprinkled with texturing materials, could represent dead grass or raw dirt.

I’ve not really thought about inorganic texturing materials to make that work… but, anything sandy or rocky, or granules made from foam rubber put through a blender, or chopped synthetic fibers of some kind, come to mind.

[Rick_Marty]

I have learned to just keep it simple.

I have used patching cement, mortar mix, and combinations of each. They look pretty good if your after a Concrete roadway but over time they begin to fail. Usually cracks and separations at joints and stopping points. This seems to be exaggerated on raised wooden structure because of the expansion & contraction of the wood structure. It is also kind of expensive, lots of waste and time consuming to install.

I started using 90 Lb. mineral surface roofing felt several years ago. It is fairly inexpensive and easy to cut and place. Doesn’t matter what color because I place the back side up. Just a little dusting of gray, brown, black etc. spray paint and it is there for years with no problems.

A couple of pictures that sort of show the results.

[ctown2 (Craig Townsend)]

Thanks for the suggestions and ideas.

Rick thanks for some tested and refined methods.

Sounds like whatever option I go with might have issues one way or another.

Nothing seems to last outside long term anyways it’s all just a matter of how long until it needs fixing again.

I’ve got plenty of roadway surfaces so I might just try a variety of methods and see what lasts long term and what I like. I haven’t had an issue yet with cracking with the patch filler on my buildings, so maybe there’s hope for that?

Rick,
Do you attach the roofing material at all or just lay it flat?

[Rick_Marty]

Craig,
I use 1/2 by 1 1/2 cleats glued to the roofing material about 12-16 inches on center. At joints I lap them 3/4 by 3/4 on each piece. Liquid nails works pretty well and the cleats are easy to snug down into my base gravel.

So far, almost 3 years, I have had zero problems with this system. Like I said quick, easy and looks acceptable.
A couple more pictures from today, buildings removed to clean up the Madrone leaves and bark.