I had been planning to use 4x8 sheets of 1" Foamular 150 (over 5/8" plywood) as the primary ‘base’ for the areas of my layout that have flat terrain. I recently discovered that 1" Foamular 150 is not available in Central Florida unless special ordered in a 48 sheet ‘bundle’. I only need about 15 sheets so I’m not going to special order the 48 sheet bundle.
Home Depot does carry/stock 3/4" Foamular 150. I could use a single layer of 3/4", or double up and have 1 1/2" foam base. I want to use the foam base in case there are places I want to be able to contour slightly below grade (ditches, culverts, etc).
Advice/recommendations on a single 3/4" sheet or double up for 1 1/2" foam base? Alternatives? Home Despot also sells 2" thick extruded foam sheets, but it’s not Foamular and it’s “poly faced” on both sides (http://www.homedepot.com/p/R-Tech-2-in-x-4-ft-x-8-ft-R-7-7-Rigid-Foam-Insulation-310891/202532856).
Thanks!
If the extruded is blue, probably basically the same stuff as pink Foamular. Check to be sure, but my guess is it is.
You’ll find the 2" foam provides a more rigid base than stacking even two 1" sheets, if you could find them. I was going to recommend 2" as I was reading through, but you beat me to it[;)]
I’ve been finding Foamular with the poly face on it and it simply strips right off if you don’t need it. Again, you’re working with another product, so verify that’s the case, but I imagine it probably is pretty similar there, too.
Hello All,
You went to HD, is there a Lowe’s you could check out nearby?
I’ve found that not all home improvement centers are stocked equally. I found 1" x 24" x 96" Blue foam sheets at my local L’s. It has a tongue & groove interface on the linear edge for a great fit.
After installation over 5/8-inch medium density fiber board the seam was unnoticeable.
If you’re installing the foam layer is over a 5/8-inch base it would not seem that you need the foam for structural rigidity. A single layer of 3/4-inch foam for modeling would suffice.
In areas where you need a deeper layer for contouring/sculpting more foam can be layered as necessary.
One caveat about the white polystyrene foam board, faced on one side with foil, I have had it disintegrate when solvent base paint was applied. Where as the blue foam hasn’t reacted or disintegrated with solvent based paints.
Hope this helps.
I would encourage the use of atleast a thickness of 1 inch. In addition to other advantages it is a big plus if you use Peco turnouts. The motor and auxiliary switch attache directly to the bottom of the turnout. With the 1 inch foam it is easy to make the “hole” for the motor. etc. Otherwise you would have to cut the plywood also.
Just My 
Worth.
Bob
That’s a good tip. Different places buy what corporate has them buy with many products, so try a different place down the road. Locally-owned places will often order just what you want if they don’t have it, although the cost might be a little higher.
I like the pink because it is square when commonly found, but it’s like any piece of wood, just lighter. It can also be found T&G, as well as square I think. Depends on what’s being ordered, so inquire.
BTW, meant to say something about plywood on the bottom. 2" is pretty stiff if properly supported, but don’t doubt for a moment that any foamboard will sag over time if not. And if you do that, no need for plywood on the bottom. To my mind, that would just get in the way. But I do most scenery as liftouts now, almost all of it on 2" foam base. My biggest is close to 6’ long. For it, the layering of mountains stiffens it enough so it doesn’t sag, but it’s also supported when in place.
My layout is 2" foam supported every 2’ and in a few years is fine and I am sure will be long term as it is glued down and very ridgid…
Get the 2" foam for the base. That thickness provides more scenery opportunities than 3/4" for creating dips, etc without appearing as bottomless holes. Also, 2" foam is sturdier, more forgiving, and a stronger insulator of noise than much else.