On my previous layout I used 1/2" homasote under the main yard and it seemed to work ok. On my new layout the main yard (flat terrain) will be about 32ft long by 30 inches deep. I will use 1x4 open grid benchwork under 23/32" plywood and then I will use either 1/2" homasote or 1" rigid foam on top. Which would you recommend and why?
I'm trying to finalize the initial layout build budget. I'm currently at about... $11,000 for benchwork, subroadbed, roadbed, track, turnouts, turnout control, DCC power/control, lighting, etc. Don't tell my wife. :)
Thanks.
Modeling an HO gauge freelance version of the Union Pacific Oregon Short Line and the Utah Railway around 1957 in a world where Pirates from the Great Salt Lake founded Ogden, UT.
- Photo album of layout construction -
A lot depends on how you're attaching the track and which switch machines you plan to use. You'd have to glue everything on the foam. Spikes or track nails are an option with Homasote. It would be easier to carve ditches and other low relief features on the foam. Overall, I'd lean toward Homasote.
In my own case, I use the 3/4" nominal plywood with cork. I spike the flex track. The cork is the right thickness so only the tip of the spike actually goes into the wood, yet all is held securely without the need to drill or use excess force (mostly).
Mike Lehman
Urbana, IL
You're in Florida. Yes, you have a marvelous train room with AC that we all envy after viewing your other thread, but you won't be running the AC all the time, and when you don't the heat and humidity will build up. Homasote will absorb moisture. I'm not sure if that will be a problem, but it's something to consider. Moisture doesn't affect foam.
Can you get foam? Some of us in the South report that they can't find it. It's in stock everywhere here in the frozen north, but you may have to special order it.
How are you driving your turnouts? If you're using Tortoises, then having a solid base underneath is desireable for mounting. Foam does not give you that. I glue a 3x3 inch square of 1/4 inch plywood to the underside of my foam to support Tortoises. It seems to work fine.
Overall, I think you're over-building. My layout is open grid, 1x4 frame with 1x3 rafters. I use 2-inch foam, but no plywood at all. It works fine. The 2-inch foam is very stiff and rigid, and does not sag, even when spanning 2 feet between rafters. Your 23/32 plywood is excessive unless you are planning to climb on top of it.
It takes an iron man to play with a toy iron horse.
Turnouts (Peco code 83) will eventually controlled with Tortoises (Tortii?).
1" rigid foam insulation seems to be easy to find at Lowes/Home Despot, but I have'nt seen 2" rigid foam anywhere local.
On my previous layout I tacked the track down to the homasote but I was thinking about trying the adhesive caulk method this time. Does caulk work ok with homasote?
Thanks for the information/replies so far.
Yes, caulk works on Homasote. I've secured cork, blue foam, wood, and sheet styrene to it that way. Floral foam less so but the failure was on the floral foam side
In this environment, I would recommend foam for two reasons:
1. Easy to install and remove track. Paint the foam, install track with white glue and track nails and it really stays there.
2. You will be able to secure tortoise on the top of the 1" foam. I used 4 screws to secure the tortoise to a 4" sq of 1/4" homasote and then double-sided-tape to the foam. It lasted without movement (and tortoise does exert constant pressure) for 1.5 years. I had to take it out because I am rebuilding the basement.
In general, my layout has been 1/2in plywood on admittedly poorly done benchwork, then 1" foam. I like the fact that white glue and track nails secure the track pretty well yet I can rip it off with no damage.
NP
I can't speak to the virtues of foam, but I used Homasote on plywood (1/2" on open grid with joists at 12" or 16" o.c.). I live in a mid-Atlantic state that gets hot and humid in the summer, but the layout is in a spare bedroom with a controlled environment (HVAC with humidity control). I painted all the benchwork and Homasote and Homabed roadbed to mitigate moisture absorption. The track is Walthers/Shinohara Coce 83 flex spiked for ease of making changes. All has worked well.
Dante
P.S. 23/32" plywood is overkill unless your joist spacing is more than 24".
P.P.S. The Homabed on Homasote is only on the main; yards and spurs and sidings are directly on the Homasote.
Onewolf Turnouts (Peco code 83) will eventually controlled with Tortoises (Tortii?). 1" rigid foam insulation seems to be easy to find at Lowes/Home Despot, but I have'nt seen 2" rigid foam anywhere local. On my previous layout I tacked the track down to the homasote but I was thinking about trying the adhesive caulk method this time. Does caulk work ok with homasote? Thanks for the information/replies so far.
A yard? definately the Homasote! You will want to adjust and move tracks, add something, remove something. Realy yards do this, you will find that you want to tweek things too.
Foam does not take nails, though nobody told me this. I used nails. I saw that they would not hold well, but what did they need to hold. Gravity would hold the tracks down, the nails only need to keep it from sliding around. Hey it wouked for 8 years until I started using reed switched for train detection and mounted magnets under the trains. Now those tracks are glued, with an extra drop of glue directly on the nails to keep them in place.
What is UNDER your yard? You want to use Tortii, but do you want to climb under the tables? LIONS do not climb under tables!
Consider mounting the Tortii directly on the fascia and using 1/16" steel welding rods to reach the throw rods. Herse is a pict with Tortii mounted on the rear fascia. You can even mount them on the front fascia all in a row, easy to install, easy to wire, mount a new fascia right over the top of them. All done, easy to change.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
mlehman lot depends on how you're attaching the track and which switch machines you plan to use. You'd have to glue everything on the foam. Spikes or track nails are an option with Homasote. It would be easier to carve ditches and other low relief features on the foam. Overall, I'd lean toward Homasote.
Agree with the above. The down side to foam is you have to use adhesive which means you have to accurately lay your track correctly as you lay it down - which I simply cannot do 100% of the time, which means pulling some track up here and there to re-lay it. That is not acceptable to me and I'd hazard many of you out there end up doing the same - so my advise is to avoid methods requiring adhesive when laying track and go with the old standby of homasote and use track nails or spikes.
Homasote will absorb moisture. I'm not sure if that will be a problem, but it's something to consider. Moisture doesn't affect foam.
True, but you can seal homasote against moisture or at minimum, make it moisture resistant by coating it with something suitable. To me it's worth it to have the ability to lay track with nails or spikes for sure.
Rio Grande. The Action Road - Focus 1977-1983
If you have plywood, you don't need the structural foam, IMHO. Installing and adjusting Tortoise motors will also be easier with the thinner plywood and Homasote stack.
[Homasote does not seem to expand or contract with humidity changes in my experience -- although the underlying wood does. In fact, the Homasote Company installed some Homasote panels outdoors ; leaving them unsealed as a demonstration for a couple of years in Chicago weather and they seemed to be OK. But sealing the Homasote probably doesn't hurt anything.]
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First you need to consider the yard elevation in reference to the mainline. Fully decked benchwork w/ 3/4" ply is overkill, yet used by many. Homesote at 1/2" thickness will work fine over 1/2" ply for a 1" total thickness. Even if you still use the 3/4" plus 1/4" roadbed for mainline, you have the same track elevations. Cookie-cutter construction, using the 3/4" ply as subroadbed only and placing the thinner plywood base for yards, industries and town, city scenes may be a better choice allowing better options, Even scenery open areas can then be foam over thin ply, foam on the joists, or cardboard lattice or screening.
Modeling B&O- Chessie Bob K. www.ssmrc.org
Agree'd. 3/4 inch plywood is overkill and costs more too - kind of like my neighbor who has a huge monster truck with gi-nornorous tires just go get back and forth to work!
A half inch plywood and half inch homasote sandwich is plenty solid if supported well.
cuyama [Homasote does not seem to expand or contract with humidity changes in my experience -- although the underlying wood does. In fact, the Homasote Company installed some Homasote panels outdoors ; leaving them unsealed as a demonstration for a couple of years in Chicago weather and they seemed to be OK. But sealing the Homasote probably doesn't hurt anything.]
I agree. Before I built my benchwork, I "tested" Homasote by storing a 2'x6' panel in my garage which is not climate-controlled but subject to the wide temperature and humidity variations of the natural environment. I measured the panel several times over an extended period and found no variation in dimension. Admittedly, I painted the Homasote on the benchwork nonetheless, just in case.
P.S. Painting the Homasote also protects against the inevitable exposure to water during other layout work.
I have seen quite a bit of Homasote used in all sorts of applications over the years in my profession. Always though it was such a poor product for any uses around water/ moisture, however, I changed my belief after seeing it used as exterior siding for an out building (New England weather). 20 year old exposed, painted panels were rather intact. Only a few of the edge batten seams had swelled or deteriorated. OSB and even plywood not properly protected will fair no better. The pine battens were actually in worse shape. It"s not impervious to moisture, but unless constantly "soaked" it is no different than most other products. Used as a layout base or roadbed and properly sealed should work fine for quite a number of years.