Benchwork: Is 3/4 ply overkill?

[danrunner]

Several places I've turned to for layout info suggest 3/4 inch plywood over 2x4 base. Aside from being really heavy, is this gauge of ply necessary? Are my toy trains really that heavy? Am I missing something? I would think the 2x4 skeleton would allow 1/2 or even 3/8 plus homosote for a perfectly fine table top.

One of the places I turned was TM videos and Elliot (Bigboy) the layout genie cookie cutting an o-27 layout on 3/4's ply. Wow, that's some thick stuff.

What do you, my source for all things trains think?

Dan V

[Big_Boy_4005]

Gee Dan, I only use 1x4's under my 3/4" ply. Tom McComas built that part before I got there.[swg]

I recently tried using some 1/2" on my upper deck. I can't say I like it much, but I didn't use BC, I used CDX. The thing is it still wants to warp, and doesn't have the stiffness of 3/4". At least 1/2" OSB would lay flat.

[Anonymous]

I used 3/4" fir on my N.C. mountain shelf RR but found 1/2" to be more than adequate on my benchwork upstairs here in the Condo. Like Elliot I use 1x4s edgewise (16" on center for the grid or joists) to support the plywood + 1/2" foam+cork in my case. I always used 1/2" cdx on my HO layouts because it was readily available and cheap.

[CNJfan]

I used 1/2" plywood with 1/2" Homasote and that works just fine. Plenty sturdy to walk on while building the layout.
Tim Callahan

[ChiefEagles]

Building a bomb shelter? Not to give you a smart answer. Look at some of the layouts. 2X2's braced right for legs and 1X4's on the sides with T or L beams will hold a person. I have 2X4 to build with but that is because 2X2's and 1X4's were higher priced than 2X4's. I still may rip them. 1/4 inch is a little thin unless you are going to put something like a foamboard or something on top. Correct bracing prevents warping and gives strength. Lots of the guys are using just sheets of foam insulation and nothing under them. Good luck.

[danrunner]

Thanks for all of the advice.

Elliot, you like lesser underpinnings like 1x4s and stick with the 3/4 ply. By the way, I've watched the TM video I don't know how many times to build up the courage to build my own layout. Thanks.

Most others think a lesser ply is fine and that even the 2x4s are overkill. Interesting.

While I didn't expect a consensus on this issue, there's a lot to consider as to what is enough to do a decent layout.

Thanks.

Dan

[Anonymous]

Just like in any construction, the thickness of the sheating depends on the spacing of the joists. I used 2X3's @24" on center with 3/8" plywood and 1/2" foam on top and it is a little springy. I did this for weight so the table can be picked up and stored. If I had to do it again I would use 1/2" plywood and 16" OC spacing or 5/8" plywood with 24" OC spacing.

[Anonymous]

There are lots of good opinions on here from lots of experienced train hobbyists.

For me, I went with 2x4's and 3/4 inch plywood with a 1/2 inch of homasote on top of the plywood. Is it overkill? I don't really care if it is because what is important to me is sturdyness and strength to hold me up while I'm crawling around on top, and also I do not ever want it to warp. Nobody looks back on building their layout benchwork and says, "Gee, I really wish I'd used materials that were not this sturdy." UNLESS, you are going with a 4'x8' layout and you plan to move it a lot. If you're building it into a room, you will not regret doing with sturdy materials. Is that overkill? Not for my layout.

[Anonymous]

If you "over-engineer" your permanent layout's construction or railpower wiring, you will be hard pressed to ever find a reason to regret it.

[SPFan]

We use 1/2" plywood on 1 x 4 frame (3/4 x 3 1/2 actual) spaced at 1 foot intervals on our portable modules. The legs are 2 x 3s. For a stationary layout you could space the frame out to 18" or maybe even two foot intervals. The plywood is glued, then screwed to the frame. Its plenty rigid enough and we have never had one come apart..

Pete

[Big_Boy_4005]

Well guys, there are so many ways to do benchwork. I was in a number of clubs in my younger days. Each modeled in a different scale, and each used a different benchwork design. All of this was long before foam was ever heard of.

I took "lessons" at the 3/4" plywood "school" when I was a member of a 2 rail O club. Those guys actually used a surveyor's transit to level the layout. 1x4's were too light. They used 1x6's.

The HO club used classic L girder with "spline" roadbed. For those not familiar with spline, it is a very labor intensive construction method, but when complete, it is very strong. One by pine is ripped into 1/4" strips, then laminated together to form the subroadbed. Some methods just keep adding laminations, while others use spacer blocks with only 3 splines per single HO track. In the end, that subroadbed is also 3/4" thick.

The bottom line here is not really so much about the thickness of the material being used as a top. It is really about matching the support spacing to that material. I've always gone for 2 foot spacing and grid style framework. This lends itself well to 3/4" ply. The other main advantage of 3/4" comes when you want to transition to grade. It's thickness resists bending, and forces you to keep the transition gentle. It is easy to over bend thinner material.

In the end, do whatever you can to create a smooth and stable base for your track. There are a lot of proven construction methods out there, pick one or create your own blend to meet YOUR needs.

Whatever you do, HAVE FUN!!!!![8D]

[fwright]

I've built 2 O layouts. The first one (4x8) was 1x4 framing on 16 inch centers with 1/2 inch plywood - heavy but otherwise great. L girder legs with 1x2 diagonal braces. Can walk on it just fine.

For under the Christmas tree, I wanted something a lot lighter but still strong enough to put a full size Christmas tree on. Layout size was 4ft x 5ft with notches at 2 corners. Built a 1x3 picture frame with 1.5 inch thick foam glued inside the frame flush with the bottom of the frame. Glued 1/4 inch plywood on top of the foam so I could use regular track screws to mount track and accessories. Worked far better than I ever dreamed. Can stand on it without harming it. Can carry it by myself. Track and accessories stay in place when layout is stored vertically.

My only mistake was not truing the picture frame before gluing the foam. I built the frame on a non-level surface, which skewed the frame some in the vertical axis. When I glued the foam in place, the skewing was locked in by the foam's rigidity, and could not be taken out. So now the layout has some unintended grades towards one corner.

Based on my experience, all future layouts will be built bed frame style with 2 inch foam supported by "slats" at 16-24 inch intervals, and 1/4 inch plywood on top where needed as subroadbed for track and accessory locations. I move too often, and with modeling the OF&S (old, fat, and slow), walking on my layouts is not sufficent justification any more for the weight of traditional construction.

yours in not-so-true framing
Fred Wright

[IRONROOSTER]

I have used 1/2" plywood, B/C on a grid of pine 1x4's with cross pieces at one foot. This has worked well for several years.
Enjoy
Paul

[Big_Boy_4005]

I'm beginning to see a pattern developing here. That is, for thinner plywood, tighter support spacing. Perfectly logical.

There is nothing wrong with light weight materials, but sometimes it takes more of them to get the same strength.

Weighing over 300 pounds, I don't feel comfortable climbing or leaning on anything less than a 1x4 on edge. No 2x2's or 1x2's for me. 2x4's are for legs and supports, and 1x4's are for framing. This is in spite of the fact that 8' 1x4's and 2x4's are similar in price.

By the way, there is well over 100 pounds of track in that pile in the upper right of this photo.[;)]

[4kitties]

I also use 1/2" BC plywood over 1x4's with 2x2 legs. With a long drywall screw from the edge of the benchwork into the wall stud every 8 feet or so, my layout is rock solid and doesn't budge no matter how hard I try to shake it. I've crawled, sat, and stood on it to install an air conditioner, and it has never given me a minute's trouble. I built it 3 years ago and have had no problem with warpage either.

I guess I'm that one person who actually DID say "Gee, I really wish I'd used materials that were not this sturdy." I used 1/4" plywood on the benchwork of my former HO layout, and it was really easy to cut for adding things like basements to structures, or water features. When I built my current layout I used the 1/2" ply, and more than once I've wished I'd used 3/8". Then again, this benchwork will last me into retirement.

I guess the bottom line is that each person's wants and needs are different. Gather the opinions of others as you've done, and then build with what you're comfortable with. Enjoy!

Joel