1/2 inch or 3/4 inch plywood? - Model Railroader Magazine

Now let's look at the downside of oversized materials in construction:

1. Cutting. You have to cut all that overly-thick plywood. 3/4-inch plywood is much harder to cut than 1/2-inch plywood, meaning more dollars wasted on worn out saw blades, and time wasted on making the cuts, since it takes longer to cut the thicker material. If you're building table tops, that's not a consideration, but it you're using the cookie-cutter moethod or cutting roadbed strips to fit, extra time will start to add up.

2. Weight. One average-strength man can handle a sheet or 1/2 plywood without a whole lot of grunting and straining. He can not easily handle a 3/4" sheet of plywood. It can be done, of course, but an arm in a sling from a strained elbow, one week in bed because of strained back, or damaged equipment (perhaps including locos, rolling stock and structures) because you couldn't hold onto the plywood and wound up dropping it onto the layout will add a whole lot to your model railroading fun, won't it? Simple to just get a friend to help lift the plywood sheet to the table to cut it or install it or whatever, but now you're working around someone else's schedule along with your own.

3. Cost. If you're building a layout larger than 5X10 feet or so, the cost of the over-thick plywood will begin to add up. $50 extra will buy you maybe three or four sheets of 3/4" plywood instead of 1/2" plywood. If you layout will wind up using more than that, you'll wind up wasting even more money.

4. Peace of Mind. Maybe this applies to me only because I'm a structural / mechanical engineer, but my peace of mind comes from knowing I've done the job right, not from building airplanes out of lead sheeting, so to speak. Because of my background I know I can use the lighter material and have a sound structure. But without being a structural engineer, maybe that doesn't apply.

But that's just my perspective on the subject. Certainly using 3/4 inch plywood will not be a detriment to your construction, unless you decide you can get away with fewer risers and a less-solid benchwork as a result. Then you might actually create more problems for yourself than if you'd gone with 1/2 plywood.

To each his/her own.