I am planning an HO scale 18" wide shelf layout & plan to use foam board. Does anyone know from experience how long of a span I could have between supports for either 1" or 2" foam board. I just plan to have the usual scenery & structures, no heavy weight items. I am asking about the insulation board, not Styrofoam. thanks
I use 2-inch pink foam and the supports are on 16-inch or 18-inch centers. It could easily go 24 inches. I also model in HO. The foam is very stiff and shows no appreciable sag with scenic material, trains and structures on it. If your layout is only 18 inches wide, you don’t need cross-supports at all.
I would go with 18-inch spacing, though, for structural strength of the benchwork. It’s also helpful to have something solid once in a while that you can mount terminal strips and small circuit boards on. If you are planning on using risers to change track elevation, you should have closer supports for those, too.
LION found the 1" to be satisfactory, braces should be 16" apart, enough to get a drill in there, closse enough to provide support. LION has built several mini-tables and then mounted these on his layout. Here is a picture of such a module. It works just fine. They say that foam does not take nails well, but I did not know that five years ago, and so used nails anyway, and have had no problems since.
Don’t forget that if you are using the foam board for a base, that when you cut rivers and valleys into it you will need additional support in those areas. You can glue more foam on from the bottom.
If you are using the rigid, extruded pink or blue board, and NOT the white expanded bead type, and with nothing under it, I think I would keep supports at 16" on center. If you were to put plywood or particle board under it, say 1/2" thick, and glue the Styrofoam board to it, which I think would be the best way to go, you could probably stretch that out to 24" with no problem. I’m talking the 2" thick styrofoam. Just my preference, I don’t think I’d go with 1". If you use 1", for sure your going to need something underneath.
Mike.
I do not plan to use any plywood under it because i have yet to see a piece of plywood that is flat or remain flat. Let me make sure I have explained this correctly. I plan to use shelf supports mounted to the wall & lay the foam directly on them.
Plywood warping is a factor of the construction process. It depends on the quality of the wood and quality of the glue. A good furniture grade ply will stay pretty straight.
Didn’t really mean the metal shelf supports you would get from Home Depot. Just didn’t want to go into a lengthy explanation. I have some nice wrought iron ones that would look good in the room & since the studs are 16’ 0n centers, I would like to fasten them to the studs. From the replies, it seems that 16’ on centers would work. I plan to use a piece of 1" on the top to carve away for elevation differences so I wouldn’t have to weaken the 2" base… jerry
OK, I wasn’t sure if you were using wall brackets / supports, or legs to the floor, so I think I would stick with the 2" thick, and keep the support spacing at 16" to…maybe stretching it to a max of 20". Any landscape feature that carves into the thickness, like a ditch or a creek, etc., you might want to add additional supports in that area. The stuff is pretty rigid, and holds weight pretty good, but when it goes, it goes all at once. No cracking or warning, it will just break. I guess you’ll have to experiment, take a piece and see how it feels at different support spacings, keeping in mind the various materials your going to use for scenery, and the extra abuse the front edge might take. Of course, anything you add to it in height, say more foam for hills, etc., glue it to the base foam, to make a solid connection, and that will help with the support.
Mike.
I’d be concerned about the shelf brackets. How do you plan to fasten the foam to the brackets? If they’re flat and have a reasonable amount of horizontal surface, some amount of latex caulk should work, but if the brackets have a round cross section, or are fairly thin, then you might want to consider adding some structure so you can make sure the foam stays put. I like foam, but it doesn’t hold screws and nails at all.
Another “must-have” would be fascia on the front. Foam edges will dent quickly and get pretty beat up.
I built my HO layout as 1 inch extruded foam {blue} over 12"OC open grid.
I have no problems to report.
[8-|]
The articles I have seen using shelf brackets have used a strip of 1x laid flat and screwed to the bracket and glued to the foam. As pointed out, you will need a fascia to protect the front edge of the foam. The 1x on the brackets gives you something to attach it to.
Good luck,
Richard
Richard, excellent idea as to placing the 1x on the bracket. I would also recommend the “heavy duty” type that uses the double “slot” attachment to the shelf standard. You will recognize these as the double "U’ shaped brackets that engage the standard w/ 4 pronged hooks.
Bob,
I agree, those are the type recommended in the demonstrations with the slotted track attached to the walls. However, he has some wrought iron ones he plans to use. Hopefully they are made with holes that he can run screws up through.
Have fun,
Richard