I have an idea for a train table but i want to run it by the pros to make sure it will be ok. I am going to make supports out of 1x4’s and 2x4’s. the top wpuld be made out of multiple layers of foam. My questions is do you think the foam is enough to put down or should i put a piece of plywood and then put the foam on top of that?
Depends. I am putting a 5/16 subflooring [very hard and dense particleboard] and then 1 inch of foam. Buckeye builds his with L and T framing and just uses thick foam. It works great. Reason I am going with the underlayment, can only get 1/2 inch foam sheets in my area. $11 each. 2 inches of foam would cost me $44. [:O][V] Just wait. You will get some photos on building.
I was going to go with the L and T framing as well. I am thinking about starting out with 4" so i can make rivers and valleys. Should i glue all the levels together or just leave them loose? Also, should i fasten the bottom level to the framing or just let it sit on top of it?
You will need to glue the various levels of foam together as the sheets of foam have a tendency to slide. Liquid Nails makes an adhesive designed for extruded foam. As to the bottom level, if you have it framed with lumber you probably won’t have to glue it down.
1" x 4" framing with 3/8" or 1/2" plywood on top will be a very strong tabel.
Then go to town with the rest of your layout.[C=:-)]
Being I already have most of the wood needed I will splurge and buy the foam to lay on the plywood as a base for sound deading and for the rough scenery.