Will be starting a large layout this year in basement. (will have 1600 sq ft to work with). My past smaller layout was 1/2 inch ply and 1/2 homasote but seems like a lot of work for a large layout. Looking to have point-to-point around walls including some walls constructed 90 degrees and about 20 feet long for islands to give me about 250 ft of mainline. Want to use open grid construction with 1/2 inch ply and 2 inch extuded foam on top about 2 feet deep in most areas. Will the foam be strong enough not to (dent in) if small things are dropped on it or a bit to much wieght put on it. I like being able to carve into it for land forms but am I asking for problems over the long term or does this stuff hold up well. Does the pink or blue type make a difference ?
It depends on how big your open grid is? Are you saying the 1/2 plywood base goes over your open grid? Or is the foam going directly over the open grid?
The stuff is pretty strong, I have the pink 2" foam over a 1/2 plywood base, and I can lean on it with a lot of pressure with hands and elbows all I want. Just can’t stand on it, or knees tend to make depressions.
2" foam over an open grid with 2’ centers will hold a lot of weight. If you put plywood under it, even more.
Yes, it will dent if you drop a hammer on it or press really hard in a small spot. Once scenery is added the small dents don’t seem to show in any I have seen. I would recommend a facia around the exposed edges so that things that bump into the layout will not damage the edges.
Pink and blue are the same thing, just make by different companies, Owens-Corning and Dow.
I enjoy working with it. Different folks have luck with different methods of cutting, lineoleum knife, steak knife, saber saw, hot knife (be sure to have good ventilation) and others. If you do use some sort of sawing that creats “sawdust” a can of static spray will help keep it from coating you and the things around you.
Yes. Cork on the foam for mainlines, and yards can be directly on the foam. That’s exactly what I did. Just use cheap acrylic caulk. And use the caulk for the track onto the cork roadbed.
Also, you should paint the foam with an earth tone latex paint first, before you lay down the cork roadbed.
PLywood underneath will strengthen the 2 inch foam.
2 inch foam is plenty strong by itself if on 12" or 16" centers supports.
It wil last for years, even in extreme weather changes. That is what it is designed to do. Insulate houses and buildings in all temps.
If you drop a hammer on it, it will cause a dent.
I f you climb on top on your hands and knees on it, your hands and knees will likely leave indents as well.
If you avoid those two things, dropping heavy things on it or climbing on top it, you will have no problems. If you do get dents, you can spackle over it to level back out.
You can avoid all that by making sure your reach to the back or middle of the layout is easily within your arm span’s length.
{If on the other hand, if you frequently drop things or plan to climb on top it, then perhaps you should consider 1/2- 3/4" ply as a base over 2x3 or 2x4s and hard shell {plaster} scenery.}
I use bead foam 2" over open grid, then cover the top with plaster gauze, even have a disabled friend who puts his weight on it and even though I cringe, no damage at all!