Where I live on the west coast and where my layout is located means my layout will likely be unaffected by climate extremes such as humidity and temperature. I have no experience with the warping wood problems. But after talking to friends and relatives back east and down south, things are heating up and moistening up again for them. Reading on the forum how some layouts are affected by the extremes in the weather, I am just wondering what it is that buckles to cause the destruction of trackwork? I am assuming it is the various types of wood that are used in a layouts construction. That being said why don’t more people build their layouts out of other materials?
A layout using steel studs with foam on top and foam risers and foam roadbed would take a lot of wood and warping out of the equation. While some or all of these materials may not be ones first choice for layout construction, they may remove a lot of warping issues.
Steel Studs are dirt cheap and there is even cement board available for those with deeper pockets and that won’t give you problems.
My question is why do people not explore the new products that keep coming along, rather than keep going back to the same ones that keep causing the same problems. Are the trade offs not worth it? Or are some us just unwilling to experiment. Maybe it’s time for benchwork to evolve a bit. However it might be something for the younger generation to take on[:)]
I tried a “new” method and eliminated plywood completely by using insulation foam sheets glued directly to the benchwork as my layout base.
I found the insulation foam sheets themselves are not flat, but may have a slight bow in them. That, combined with any uneven-ness in your benchwork will create minor surface irregularities. And at the joints where one foam sheet fits into another, you may end up with a dip or rise in the layout surface. All of this before any expansion/contraction due to weather.
Also, you need to keep in mind that things as simple as sunlight do create stresses in a material. As sun shines on any surface, the top heats up and expands–thus causing contraction on the cooler underside of the surface. In the real world, with 13" or 15" concrete pavement slabs, the thermal stresses just due to the sun and nighttime can actually cause greater stresses in the pavement structure than traffic loadings.
In most cases, on a train layout, the surfaces are not so big that thermal stresses matter at all–the effect is not enough to see or notice. For most modestly sized train layouts, that have curves in both directions, the temperature stresses are equalized out at the curves (unless all joints are soldered) such that expansion and contraction of the rails will not be a problem. However, for the larger train layouts with long track runs, the temperature stresses can cause lifting of the track if the glue holding it down is not strong enough. I have witnessed this in person on a friend’s attic layout that had a 4 scale mile mainline. Heat kinks and glue bond breakage between the plastic ties and cork roadbed were common. (He was not using any nails because he did not want to transfer sound from the track into the plywood, where it is amplified).
On my own layout, I can see the gaps in some of the rail joints a
First, my current layout was started in 1984 (meaning most of the basic benchwork) and is still doing quite well today, fully sceniced, etc. I use the old traditional plywood sub base with Homabed (commercial) for the track laying. My location is Kansas City Ks which can get verrrrry humid in the summer and verrrry cold in the winter. My basement is insulated with sheet rock and the furnace/air system is located in one end of the railroad area.
I say this to reinforce my statement that I do not have expansion/contraction problems to any degree. Once in a great while I may find a crack in scenery that has to be repaired, but the tracks, some of which date back to 1984 beginnings are just fine. So I am fat and happy and running trains. Oh, my tracks are held to the roadbed by spikes, and the roadbed is held down through the Homabed to the plywood. I may be just lucky, I don’t know. Outdoors I have a garden railroad that is radio control/battery power and I use aluminum rails which do expand and contract, but that is a different story.
Brent,I use lumber because my past layouts have been keep under A/C in the summer and heat in the winter and I never suffered warpage…Now on my ISLs I use 18" centers on my cross bracing which makes my normal 10’ ISL solid.
Also note I had to keep my past layouts portable and easy to set up and take down when not in use.
IF I was to wall mount a shelf layout I would use 12" metal shelving brackets on 18" centers-18" centers usually lines up with the wall studding…
I have always used the traditional methods of building benchwork and this iteration of the layout is the first one where I have had any warping. It wasn’t serious but I do see larger wail gaps that weren’t there before. I can’t buy Homasote locally - no one carries it - so the plywood does expand/contract with the changing seaons.
LOL - WAIL GAPS?? Must be doing my Elmer Fudd imitation…
As I responded just seconds ago to this question on trainboard, it is almost certain to be over 90% due to humidity, and virtually never to do with temperature. The only time temps could be pointed to is when virtually every joint is soldered and the tracks change temps over maybe a 20-30 degree range.
Someone on that other board posted maybe four years ago that the coefficient of expansion for NS rails is very low. He was an engineer and did the calcs for us, showing that 100 linear feet of Code 100 NS rails would expand a whopping 1/4" (gasp!) over a 30 degree rise in temps…wow… What that means is that if you do have 6-10 gaps left mobile over that 100’ length, each gap would close by about 1/32" when the temps in the layout room rise by 30 deg! It’s nothing…negligible.
On the other hand, wood expands along the grain commensurate with changes in the relative humidity in the space occupied by the layout. If the wood expands, and the tracks are fixed even indirectly to the benchwork, the chances are excellent that the expanding wood will draw the rails with it, thus forcing the joiners to slip and let the rail ends move apart to accommodate the movement. Now you have 1/4" gaps instead of the 1/16" gaps when you first powered your rails.
If those 1/16" gaps are closing, and forcing the rails to buckle and lift, or to snake left and right, it suggests to me that the linear dimensions of the wood framing is the likely cause by quite a margin. Depending on the orientation of the linear frame members relative to the rail axes, it is either wood expansion or wood contraction.
I use a cheap humidity monitor made in the PRC available from Canadian Tire. It is a metallic grey plastic thing found with the thermometers…made by Accu-Temp. When it says my relative humidity exceeds 65%, I know to clean the screen on my dehumidifier and get it going. It is buzzing away not 14 feet from me as I type.
As I have mentioned[(-D] in the past, I build everything below my cookie-cut plywood subgrade out of steel studs (or other steel shapes, like angle iron.) Unlike forest products, which can and do assume wierd and wonderful (NOT[|(]) shapes when exposed to the hot, dry conditions of the Dessicated Desert, steel studs don’t warp, twist, cup or otherwise become useless for benchwork construction. Since the railroad profile I’m building is only level between yard limit signs, my work-in-progress looks like a thrill ride under construction - but I can and do operate.[^] The only problem I’ve had to date (4+ years) occurred because I didn’t leave adequate expansion gaps on some track I laid in January of last year.[oops] Four lengths of Atlas flex had to be lifted and re-laid about a millimeter farther apart.[:I]
There’s a thin layer of foam insulation (carved into roadbed) on top of the plywood subgrade, held down by latex caulk. The flex gets laid (anchored with latex caulk) on top of a full-size cardstock track template that is sealed with paint before being caulked to the top of the foam roadbed. Any tendency of the plywood to deform is beaten into submission with steel angle iron screwed to the underside.[:-,]
What I really like about steel studs for L girder style construction is that there’s almost no waste. Odd ends become risers, or brackets for mounting components of the electrical system. The little cap screws used for everything are a lot less expensive than decent wood screws. Screwing flanges on risers are formed in seconds with tin snips and bending pliers, not added on. Also, unlike wood, steel is a precision product of uniform section and consistency.[8D]
To say that I’m pleased with the results I’ve achieved with steel is a gross understatement.[^]
Incidentally, Larry, wall studs are usually 16 inches on centers (3 under a s
Incidentally, Larry, wall studs are usually 16 inches on centers (3 under a sheet of wallboard.) Some ‘el cheapo’ work is done on 24 inch centers if the crooks think they can get away with it.
Chuck
Chuck,That could be but,the houses I lived in over the years was set at 18"…The 16" may be modern…
I live in the deep South, central Georgia area, where high humidity will drain a person in no time flat. My layout is in a separate, from the main house, air conditioned room. The basic framework is of wood with foam insulation boards on that. Even in this temperture controlled environment I had some minor track warp take place a couple of years ago, so I started using a dehumidifier and, so far, everything has been doing well. I empty the machine of … oh… about a little over a quart of water per day when the humidity is extra rough.
I’m with Crandell in that I don’t think heat has a lot to do with expansion of track, I’ve never tested the theory but others have and they say it’s no theory at all, just fact.
I would highly recommend that anyone, who is going to use wood in their layout construction, to leave the wood in the layout room for as long as they can to let the, I’m assuming, ‘green wood’, dry out. That would probably solve some problems. But, if they live in a high humidity area a dehumidifier is the way to go.
As far as your question goes, and I almost forgot. I think most still use wood because it is, for them, easier to work with, and that’s a guess on my part.
So what I am reading into the responses so far is, warping layouts may not be as prevalent, or as big a deal, as some threads that have gone on for pages in the past have made them out to be.
Chuck uses steel, iron, foam and wood. Chuck would you trade the wood you do use in on foam or some other product if you were to ever do it again? I guess what I am looking for is lessons learned kind of information.
Crandell. Whats the construction of the new layout going to be like, any thoughts yet?
I have really experimented on this recent layout. It is mostly foam on 1 x 4 grid and spline. Like chuck I have used steel studs, angle iron, cement board and other weird and wonderful things on other parts. Maybe its time to reference these new materials more to new comers along with old tried and true ways and they can decide from a broader spectrum. Just my[2c][:)]
Having a layout in a climate controlled environment would be ideal. Not all can have that, I guess.
But A well built frame and allowances for expansion and contraction for those in “climactic peril” should do well unlesss they build it out of concrete {as you do mention}. Even then, the trackwork on top it, if allowances are not made for expansion/contraction will cause troubles as the rails will expand and contract.
AS mentioned a foam based layout can do well without much trouble…but a lot of “climactically perilous” modelers don’t have access to it because their climate doesn’t warrant carrying it in a store.
Cement board over steel studs is a novel ideal, but generally not the first thing modelers think of when they build a layout, regardless of their pocket size.
For the amount of TOTALmoney some DO invest in their layout it seems to me that a propane, gas, or electric heater on low heating and A/C on minimal added to keep somewhat climate controlled on a layout would seem reasonable to have to me.
But that just me. And my layout is in the house, climactic controlled. Not in a garage or shed. Without climate control. And while we do have swings in temperature/humidity/weather patterns, ours may not be as extreme as others in our country experience. And my local Lowes and Home Depot DO carry the extruded foam I used on top of my wooden frame, with support members placed just 12" apart and well glued to be sure it did not warp. Just my [2c]
Brent, I can get good quality milled lumber, 1X4’s are what I use, locally. I do let it sit for a week in my basement, and I do control the environment seasonally with either a dehumidifier or a humidifier. I haven’t had a budge out of my now four-year old open framed clear spruce bench.
I also use splined roadbed, and that probably helps a lot. It tends to float on the risers which can bend back and forth as needed.
I don’t intend to change for this next go-round. I have the tools and know-how.
Foam is nice in the fact it is light, is dynamically stable, is unaffected should it get wet, and is readily cut. It does have issues with sound transferance, reacts badly with petroleum based products, can withstand some flexing but will dent under impact forces, and doesn’t hold screws/nails.
Steel studs are priced similar to 2x4 material in my area. They can be useful in some situations but require different methods and tools. While wood may expand/contract, I prefer it for it’s other characteristics, that would be the ability of flexing under load and returning to its shape. The expanding and contracting can be minimized by simply sealing the endgrain on dimentional lumber, minimizing knots, keeping it away from concrete, acclimating it to the room, and not asking too much in regards to spans and weight. Wood is readily available in any length and size, regardless of your locallity, and readily takes all screws, nails and glues. I prefer wood I-beams made from 1/4" luan and 1x2s. They are not prone for sagging, handle decent weight, are very light, and can span long distances.
My layout is in a Minnesota basement. The humidity right now in the layout room is 55%. It is 80 degrees outside today and very humid. The upstairs is 41% humidity, and 77 degrees right now. The layout has been up since about 1988 and the framing is built out of 3/4" plywood ripped into ‘dimensional’ lumber. 1/2" plywood subroadbed is screwed/glued to it. I have Homabed roadbed glued to the subroadbed for the main lines. Atlas code 100 flex is spiked to the Homabed. I have had no warpage issues, even after ballasting/scenery work were done. A previous layout did have a 30" radius curve ‘buckle’, but I suspect I had the rail joints too tight I now leave a small gap(width of a Xacto #11 blade) on all rail gaps.
Our current club layout has 1x4 framing with foam laid over 3/16" plywood. Atlas cork roadbed is glued to the foam, and Atlas code 100 flex is glued to the roadbed - no big problems on a double deck/27’ by 27’ layout. This is even with folks of varying skills building it!
The bottom line - Well engineered construction usually does not fail.
Wow, I hope then that they used 54" wide sheets of plywood. Actually Brakie is right, depending on the age and area, construction method varied. I tend to find that here in N.E. that many homes built balloon frame did have many of the studding, joists and rafters divided by the wall/ floor run and end up about 17- 20" O.C. These used wide pine/ fir sheathing and subflooring. Modern dimensional materials didn’t matter.
One last comment about stud spacing. A family I once knew owned a balloon-framed Late Victorian. Not only were the studs spaced oddly - different in each wall! - but they were full-size 2 x 4s, not modern dimensioned lumber. Every time they needed work done they had to pay premium prices - a modern 6x6 would rip down to two suitable 2 x 4s plus some laths for their lath-and-plaster walls.
I think that the construction of the several Levittowns right after WWII began the modern era of everything being designed 16 inches on centers. Those developments were designed to use full sheets of plywood and wallboard with minimum cutting.
Would I substitute foam for that one layer of plywood in my cookie-cut roadbed. Nyet! Its primary purpose is to provide a holding ground for screws, something for which foam is totally unsuitable.
Just as the squeaky bearing gets the grease, the failed/unsuitable benchwork assemblies are the ones which make the posts on forums. If 100 people build identical benchwork from identical materials and ONE turns out a lemon, which one do we hear all about?