I am building a 10’ x 2’ switching layout for my office on a piece of 2-inch thick pink foam board. If you have done something similar, how did you frame it? i am thinking a simple box with triangle-shaped piece of bracing at each corner that will support the foam and maybe someday legs (right now it is going on top of a bookshelf unit at each end). I’m looking to have it be lightweight so I don’t want a full-bottom. Is foam “strong” enough to support itself across that distance or should I put a couple of braces in the middle? FYI, across the center will be a wandering 1-2" wide indentation carved out maybe 1/2" deep for a creek.
I’m certain this will work but I wonder if anyone has any other ideas. I’d be interested before I pull out the saw. Thanks, guys!
While the foam is strong enough to be self supporting, you don’t want to tke the risk that a small accident will send the whole thing crashing down. I’d run about 7 1x2 stringers across underneath for some extra support. BTW, not being sure what your actual plan is, you probably son’t want to put your layout down in a box. The edge of the layout should be flush with the edge of the frame.
Use another 2" peice of foam with a couple of alluminum extrusions cut into it (so that they end up next to the other foam bottom. It will be strong as can be but still lightweight!
I’m considering something similar, and planning on using a thin (1/4" or thinner) plywood box, with quarter-round molding around the inside. The molding will make a ledge for the edges of the foam, and be recessed just enough to make the foam surface even with the upper edge of the plywood side.
The plywood box will act as both layout support and fascia.
What I did was built a frame around the underside of box out of 1 x 3 and I used a 1 x 2 to brace the table down the center. I also used precut 2 x 2’s for legs and eventually mounted some dry wall screws to the inside of the 1 x3s and mounted it to a wall. semi table/ semi shelf – Steve
I built my 3.5 x 5.1 foot HO scale layout as 1" blue extruded foam {same as the pink} over open grid 12" on center. 12" on center may have been overkill!
Works fine {as long as you have no intention of climbing on it!}
I used 1x4s as the frame around which the 1x2s that were used to support the foam.
Again, works great!
You could go 24" on center I think with the 2" foam and still have sound support.
I would go with,RREBELL,SUGGESTION, but I would add two more support brackets,somewhere in the middle of that 10ft run, especially where you plan on the creek. That’s a pretty long,span,with no center support…
Use inverted 'L" girders for the outside (1x3 with a 1x2) and drop the foam inside. A couple of 1x2 cross braces laid flat will complete things. According to Lynn Westcott’s analysis, you can span about 10ft with minimal sag with “L” girders of that size.
My switching is 13’x 18” and is in a bedroom so I wanted it to look somewhat nice.
I used 1x4” clear pine stained light oak for the box and used 1x3 clear pine for the legs and supports. I ran supports across the bottom about every three feet and set them to bring the foam up to the edge of the pine. Its light enough that me and my wife can move but sturdy enough not to be real wobbly.
It’s still a work in progress, I need to put the curtains up to hide what I store underneath it yet.
Foam comes in 4 * 8 sheets, so your ten foot run will be a couple of pieces of foam, say five feet, with a joint in the center. So you want a support under the foam where the joint is. Foam is pretty strong, but you want to watch out for accidental loads, like some clod leaning on it. A five foot run will probably give enough under an accidental load to pop out of just some end supports. I’d want a decent wood support piece every 2 or 2.5 feet.
I put a solid plywood bottom to my 1 * 4 frame to stiffen the frame, and give me something to fasten under table stuff (switch machines, terminal blocks, wire hangers, etc) to. 3/8 inch is enough. Plywood isn’t too heavy.
