Truth be told, most of our train tables are probably overbuilt. The size and strength of them isn’t the only consideration, and overbuilding them probably does make construction a little easier. But we also don’t need to go crazy with our materials. Here’s how much weight a train table can support.
How much weight a train table can hold
To figure how much weight a train table can hold, we have to figure the individual parts. First, the lumber.
Wood can bear weight of 625 pounds per square inch. That means 2×4 table legs are serious overkill. You could easily get by with 1x2s as table legs in this application. The main reason to use 2×4 or 2×3 lumber is the relative chunkiness makes construction go easier. Thick legs can stand up on their own while you’re working on the rest of the table. But there’s no reason to apologize for using 2×3 lumber instead of 2x4s when building a train table. Because even 1x2s can literally support more than a ton. The legs aren’t the limiting factor here.
The surface is more of a limiting factor. I used 3/4-inch board on my tables, but that was probably overkill. Even half-inch board can support the weight of an adult male standing on it as long as it’s braced and screwed down every 18 inches or so. And yes, there have been times I’ve needed to stand on mine, for various reasons.
The table itself will weigh 30-80 pounds, but that’s not too much of a concern. At the kinds of weight these tables can support, that’s a rounding error.
What about the screws?
The fasteners are potentially a limiting factor. I recommend thread-cutting construction screws or deck screws, ideally with a Torx head. The reason is because those screws are less likely to slip and strip. That makes assembly go much faster. A box of good-quality construction screws costs around $10, and they’re worth it for the time they save you.
The screws can support about 80-100 pounds of weight apiece. You’ll be using two per leg to hold them straight and square, and you’ll probably have six legs total on a 4×8 table. So that means the screws can hold 960 pounds, conservatively. You don’t need two screws per leg, weight-wise, but you do need two screws to keep the legs from wobbling around on you.
Linn Westcott, the founding editor of Model Railroader, advocated gluing your table together, and using screws just to hold it together while the glue dried. The glue joints are as strong as the wood itself, so you can remove the screws afterward. It’s your choice if you want to do that, but it certainly creates extra steps. It’s possible in the 1950s and 60s it was more cost-effective to build this way, but when a bottle of wood glue costs $3, a small pack of screws costs $2, and a big box of screws costs $10, the savings is only $5.
My tables are all screwed together. This provides some advantages. If my kids want my train tables someday, they can disassemble them for moving and reassemble them with just a drill. If they don’t want the tables, they can disassemble them and use the lumber to make storage shelves. I’ve heard enough sad stories of veteran model railroaders having to destroy their layouts because no one wanted them that I’m glad I left my options open. That’s more than worth the $5 I might have saved.