I am getting back into HO. I will be building the WS Grand Valley set. I am wondering if I may use 3/4" foam insulation board (ala Lowe’s), properly supported of course, instead of plywood for the base. Is this a reasonable idea? You experienced folks…pros and cons please. Thanks, PF
PS: DCC rocks!
Hi Mr. Howard,
Welcome back to the hobby.
Get ready for the deluge of opinions, 'cause here they come!!!
I prefer plywood as the base. It is thin, structually sound (if it’s not too thin) and you can support stuff on both sides (track, buildings, scenery, etc. on top, wires, switch machines, DCC circuit boards, etc. below).
I have seen folks use foam, and I understand the benefits of the lightness of the material, but it is not as structurally sound unless supported around its periphery, the wrong solvent will melt its way to China (or to at least your floor), and how do you attach stuff to the bottom? Sorry, but I’m not conviced foam is the way to go.
I have a friend who is planning to use MDF (Medium Density Fiberboard) for the base of his layout. He is a contractor and likes the smooth surface and structural integrity. I think he is making a mistake. MDF does not like water - it expands and deforms when wet. He may regret using it when he lays ballast and scenery. With little or no support around the edges, where will the wiring be installed underneath?
Plywood is forgiving when you change your mind and want to move something. I’m not sure foam or MDF are as forgiving. Plywood can also be used in narrow strips, such as on an open gridwork. Foam and MDF, probably not as readily. My 2 cents.
Mark C.
It’s not a case of using one or the other, because by themselves their both a mess. Both will resonate and be loud by themselves. When sandwiched together the diffferent stiffnesses and dampining frequencies they have cancel out and they are a lot quieter.
The one issue I have for foam by itself is strength. Ever plan on leaning on your layout? How about stubling into it? Falling on it? Plywood would take it a LOT better than foam, in any incarnation.
There’s my $0.02. If enough of us chime in you’ll be able to buy a candy bar!
Mark in Utah
Started with Foam 1.5", scrapped the idea. Thought it was good but this old dog went back to the well.
“L” girder, 1/2" OSB (bad idea) then went to 1/2" plywood. The supports are on 16" centers and using Cork Roadbed and SOME woodland Scenes road bed.
We built a little over 800 sq ft and am happy with the wood.
Pictures are under my Signature.
With that said, The CONS of the foam where the Melting with a short and the fumes cutting it with a hot wire. My wife said she could smell it up on the 3rd floor. The wood was cut into roadbed width like the old days. The OSB was a pain when drilling and putting in screws for the switch machines. Murphy’s law had the epoxy glue in the OSB raising the problem.
That is my $.02[:D]
Hi Bill,
Mark is absolutely correct. Foam OVER plywood. 3/8 ply is fine.
Foam also allows you do easily create ditches, streams and other scenery below track level. Cookie cutter with normal track elevation slightly high works too but is somewhat more difficult. I would suggest 1" foam. I use a mix of 1" and 2".
Even with a pre-made set you might want to customize a bit and some day you will want to expand.
You should search on foam for many many opinions and techniques. It was a whole new game for me when I came back after a 20 year hiatus. Lots of fun new stuff to learn.
Best of luck with your layout.
Obviously the purpose of foam-on-plywood is to give the ability to “dig down” and easily create scenery lower than track level, but what about using the Woodland Scenics foam risers instead? Has anybody here tried that?
I have found a couple of folding tables 28"x7’ veneer top will support 200lbs and are not shakey.Would be able to fold up for storade if need arises by connecting the tables together it gives me a lot of options,Mainley I could turn the table on it side to do the under table wiring.Being a disable vet getting to crawl under a table would be difficult.Would this idea work or should I save the tables for family dinners.
Thanks for all your very interesting comments! Wow! My own support group. Is there a “shrink” out there who gives $.02 advice?
Seriously, I think I’ll be going with plain old plywood. WS says the kit comes with it’s own foam base so if that really means what I think it does my question is moot. I did see an interesting product at Lowe’s yesterday though…kind of caught my eye as a foam & plywood idea…it was a 3/16" thick lauan sheet…like old style cheap panelling but VERY smooth…I had considered using it with the foam but guess I’ll just be an old fart…ooops…be old fashioned and go with plywood. The comment about the foam melting hit home as the RR will be in an upstairs room with a nice new carpet, etc.
Again, thanks to all…I will have more novice questions I’m sure…your interest is really appreciated!
I to had to make the decision to go with plywood or foam when I left garden railroading and returned to HO inside the house.
My previous indoor layouts were all constructed with plywood bases. When I started my current layout I realized that a lot had changed in model railroading in the years that I was puttering around out side not only with newer and better equipment but also with newer construction techniques. I got a lot of information from this forum and tried the foam over 1"x4" on 16in centers. I quickly realized that there was a downside I thought that the noise level was higher but more importunely the mounting of switch machines, IR detectors,etc.
I had only progressed with about 10 ft of 30" wide layout when I decided that I wasn’t satisfied with the foam and went back to using plywood as a top material.
I use foam on top of the plywood as a scenery base and the combination works well for me. Joe
I also went with foam on ply–1" foam on top of 1/2 ply. I like the result.
Hey guys, I had an idea though(I know, whats that burnt smell? LOL ). You could use foam insulation board(2") instead of plywood, and make a frame out of wood, and mount the foam to the frame. It would support the foam and other items(Transformers, ect.). Just an idea though!
Thanks,
Spit
Foam doesn’t stand up to incurstions along its edge. So, it needs an exoskeleton, and is probably better off with a couple of joists under it for added security…I’m talking about 1.5" or thicker. The 1" stuff definitely needs an underlay or joist support of something.
Some fellows here swear that their 2" foam is plenty strong against sagging, and that is it easy to carve, etc. It seems that many of us favour the layered approach of 1/4-434" plywood covered with foam. You can reduce the support structure somewhat if you use the thicker plywoods, but you won’t alter the overall weight of the structure by doing so…at least, not subtstantially. And, it probably costs a lot more.
Chip’s approach is sensible. You can always stack a couple of layers, even six, of the foam of your choice using a cookie cutter method, and then have at its sharper edges with a wire brush. Believe me, that brush will have your hillsides nice and countoured within a few minutes. Yup, there sure will be a lot of foam “sawdust” after that, but a shop vac is probably going to be handy where most of us are doing this type of project, anyway. After the brushing, use a sanding block to get a smoother look, shop-vac once more, and then grab a mug and think about scenics.
DIY’s “Workin’ on the railroad” series has a 5 partseries on the WS “River Pass” kit. Episode 1 shows the 1/2" base glued to 2" foam, (although I would opt for a plywood base, I used 5/8" on mine, not a WS kit.) but they also say anything can be used as a base, ply on saw horses. Although the series was aired in winter, you can still get info from the web site, (it seems they are into Garden Railroading now for summer) the only drawback is the pics are crappy. It would be nice if they had Videos of the show or at least expandable pics to see better!
Good Luck
John
http://www.diynet.com/diy/shows_dwrr/episode/0,2499,DIY_23302_40722,00.html
http://www.diynet.com/diy/episode_archive/0,2019,DIY_23302_545,00.html
Depends on your situation. I’ve used plywood, Homasote and foam with cork and now WS foam rubber roadbed on foam.
2-inch foam is light, easy to shape and portable. It can be supported by cheap wall brackets or laid on a table or even a dresser in a spare bedroom. Virtually no time or $$$ needs to be invested to build benchwork. Foam won’t sag over 18-inch centers.
But it does dent if you’re not careful so you really need to add fascia to it. If you want to attach switch machines to the bottom, you have to laminate something like 1/8 inch hardboard to the foam or use Velcro. As mentioned, you can’t lean or stand on it and some paints will melt it although I just sprayed a test piece of track on WS roadbed on foam with a Krylon paint and there was no damage at all - should make for quick rail weathering.
For my current linear shelf layout, I wanted low cost, light weight and minimal woodworking, so I went with foam.
I use 1/4 inch plywood for a base and then put 1 or 2 inch foam over that. I would never just use plywood anymore because for me it becomes a sound board and sounds awful. I wouldn’t use just foam because I have a habit of putting one hand on the layout and leaning at least lightly on the layout.
You can actually make the benchwork, the layout etc out of only foam board. It has been done. They used 2 inch foam.
it was 8 feet by 4 feet and weighed a total of 65 pounds.
You want to use liquid nails to hold it together when you need structural strangth. However I have always used just white glue and it has worked fine for me.
I glue the foam with white glue and spread it around on BOTH pieces to be glued together. If I am glueing it to the plywood, same thing. I glue both pieces. I let it dry until it is tacky then I press them together.
If you put them together while still wet it won’t dry properly and you will end up with bubbles.
I hope that helps.
I’ve used them on the last layout and will be using them again on the new layout . They sure take the guess work out of things.
I’ve used 3/4 " plywood and 1/2 " plywood twice now put down the scneic risers then built up around them with fowm board.
With the plywood base you can also cut out of the base a run for a stream then mount the foam board from underneath for the river bed or canyon.
I will be trying that technique myself.
Lynn
Welcome back to the hobby!!
I agree with this 100%. When I came back into the hobby full time last year with my step son, this is exactly how we built our layout. Of course ours is only your typical 4x8 because of size limitations in our basement but this method worded out well. I built a table using 3/4" plywood, 1x4’s and 2x4’s then layed 1" foam on top so that I could cut it to place my “stream” and also used layers of 2" foam to build the “mountain” with tunnel. Worked out great!
I use 2-inch pink insulation foam, no plywood. My layout is a free-standing table, 5x12 feet, which does have the “exoskeleton” recommended to protect the edges of the foam. I use a modified cookie-cutter, and I cut narrow strips of foam where needed to support inclines, etc. My layout is on casters, and I like the light weight because it needs to be pushed around occasionally.
Foam will not absorb water, so if you have a humidity situation it will not be a problem. There was a discussion a while back about track warping from expansion and contraction, and many felt that this problem has little to do with the track, but a lot to do with the plywood beneath it.
On the other hand, you can’t climb on a foam layout. It won’t support the weight of us slightly-more-than-fully-grown adult alpha males. You can’t screw things underneath, although you can always attach things like terminal blocks to the support rafters. Folks in the Southwest can’t find this stuff, but I don’t know about the supply in South Carolina.
Extra foam makes a great base for mountains and rock faces. Also, you can stick trees into it, and they will stay there. I use a bamboo skewer to poke holes all the way through the 2-inches for wires, so no drill is needed.
Ditto Mark…
I have a variety of widths of foam over 1/2" plywood and it all works great. I just spent some time over the weekend carving some terrain details into the foam and it’s really great to work with for that.
One note: try getting several widths of the foam from an insulation supply company. Lowe’s probably won’t have a great selection. I found 1/2", 1", 2", and 4" at a company here in Houston. It’s all helped a lot buliding mountains and hills.
Good luck
Thanks again all! Just got back from vacation and noticed some reference to another modeler going to try the Grand Valley layout also. (Caught it on a slow dial up connection while on vacation). If you’ll contact me maybe we can comiserate…'er share ideas etc. Thanks. Bill
BTW, my start date is probably still a couple months away fwiw but am already collecting things I’ll need.