# Plywood?



## tommy24a (Mar 4, 2016)

We are doing an L girder layout. Kinda like a cookie cutter design. I see some layouts that have plywood for the sub road bed and some are using what I call particle board. Other than the cost any other pros or cons on either?

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## CTValleyRR (Jul 26, 2014)

Well I use neither. I'm an extruded foam panel convert. I'll have to leave the pros and cons to wiser heads than mine! Good luck.


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## tommy24a (Mar 4, 2016)

CTValleyRR said:


> Well I use neither. I'm an extruded foam panel convert. I'll have to leave the pros and cons to wiser heads than mine! Good luck.


No cork road bed?

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## MichaelE (Mar 7, 2018)

I've never heard of practical board. But if you mean _particle_ board, stay away from it.

It's difficult to nail, does not hold screws well, is heavier per square foot than same thickness plywood, soaks up moisture like a sponge, and is brittle. 

It's only redeeming quality is that it's cheap. That's why they make so much heavy furniture that you can buy at Walmart.


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## tr1 (Mar 9, 2013)

*3/8" braced painted plywood works fine!*

3/8" supported painted plywood works fine.
Along with cork roadbed contact cemented to painted plywood(one side only.)
Good luck now!
regards,tr1


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## tommy24a (Mar 4, 2016)

MichaelE said:


> I've never heard of practical board. But if you mean _particle_ board, stay away from it.
> 
> 
> 
> ...


Yes I meant partical board.

Thanks for the info. 

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## mesenteria (Oct 29, 2015)

tommy24a said:


> We are doing an L girder layout. Kinda like a cookie cutter design. I see some layouts that have plywood for the sub road bed and some are using what I call practical board. Other than the cost any other pros or cons on either?
> 
> Sent from my LGL84VL using Tapatalk


Anything you can measure and cut to size is suitable in our hobby. Anything. 

But.....

...some things need special care. Oriented strand board has poor dimensional stability whereas real plywood is quite stable across temperatures and humidity changes. If you have a handle on some OSB, go ahead and use it, but take the precautions that seem reasonable, such as having a dehumidifier handy when the humidity climbs higher than about 65%. Or, put out shallow pans of water when it falls below 35%. Or else. Ask if you really want to know how bad it gets.

Like the cheaper OSB, thinner plywood is cheaper, but it requires more support over smaller distances. So, you'll cut more supports out of dimensional lumber to undergird the OSB at intervals that won't permit it to sag. More cost. More cuts, more screws, more time.


A decent quality, 5 ply plywood or higher, will be more stable, sag less if it's at least half-inch, but it will be somewhat heavier to handle. Costs more per unit of measure.


Decisions.


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## tommy24a (Mar 4, 2016)

mesenteria said:


> Anything you can measure and cut to size is suitable in our hobby. Anything.
> 
> 
> 
> ...


Thanks all good points to think about. Yes lots of decisions to make....lol

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## traction fan (Oct 5, 2014)

*L-girder sub roadbed*



tommy24a said:


> We are doing an L girder layout. Kinda like a cookie cutter design. I see some layouts that have plywood for the sub road bed and some are using what I call practical board. Other than the cost any other pros or cons on either?
> 
> Sent from my LGL84VL using Tapatalk


tommy24a;

I agree that you should avoid particle board for all the good reasons already stated. For my sub roadbed, I use the same L-girder construction that you are apparently using on your benchwork. Of course I use significantly smaller lumber! 

L-girder, in any size, has the great advantage of staying super- stable. It is extremely warp resistant. If you build it flat , then by golly, it stays flat. This is often not the case with conventional plywood, OSB, etc. when used as a flat sheet. 
I use 1/4" thick Luan plywood as my sub roadbed, with 3/4" x 1/4" pine rails glued along both sides. For hidden track the rails can be on top, to keep trains from falling to the floor. On visible track I glue the rails along the bottom of each side of the sub-roadbed. I use yellow carpenter's glue for a strong bond, and to resist later moisture from ballasting. Scenery attached to both sides of the sub-roadbed acts as a "train catcher", in case of emergency. 

have fun; 

Traction Fan:smilie_daumenpos:


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## CTValleyRR (Jul 26, 2014)

tommy24a said:


> No cork road bed?
> 
> Sent from my LGL84VL using Tapatalk


Nope. Woodland Scenics foam roadbed under the mainline, glued to the extruded foam panels with adhesive caulk. The track is glued to the roadbed in the same way.


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## kilowatt62 (Aug 18, 2019)

Ive noticed that homasote is no longer in vogue as a roadbed. Comments as to why? 
Im not yet convinced about styrofoam board. Mainly due to not being a fan of glueing track down. I prefer proper gauge nails and screws.
I use 1/4" luan as a sub layer and various forms of roadbed. Ie; cork, foam, and that sticky flat stuff made by woodland and another I cant recal name of...


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## MichaelE (Mar 7, 2018)

Homasote and Luan is much too flimsy for L girder construction which is what this thread is about.


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## prrfan (Dec 19, 2014)

Styrofoam is not commonly used in layouts, although it probably has been by some. 

The foam board that’s used is 2” extruded foam, which is a totally different product. It can be cut, scooped out for creeks etc. without getting the white ‘popcorn’ scraps you get with Styrofoam. 

We’ve had many discussions about Homasote here on the forum. You can access them via the search feature.


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## mopac (Feb 24, 2011)

As for glueing track. Many use latex caulk. It holds well and is easy to scrape up if a change is needed. I would not want to glue my track either. The caulk will work on plywood or the 2" extruded foam. Use a caulk that says it stays pliable.


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## ebtnut (Mar 9, 2017)

The old-time traditional method was to use 1/2" plywood for the subroadbed and Homasote for the actual roadbed. Use exterior grade plywood since it is much less prone to humidity issues. The Homasote holds spikes well if you hand-lay, and track nails if you use pre-fab track. I haven't looked recently, but you used to be able to buy Homasote pre-cut with slots to curve it and the edges beveled. It was sold as "Homabed".


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## kilowatt62 (Aug 18, 2019)

*Styrofoam / extruded foam*

Yeah, my bad. I did say styrofoam but meant extruded...


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## kilowatt62 (Aug 18, 2019)

*"Which is what this thread is about."*



MichaelE said:


> Homasote and Luan is much too flimsy for L girder construction which is what this thread is about.


With all due respect, I beg to differ sir. 
The thread is primarily about roadbed/subroadbed/decking. 
That said:
L-girder being the most warp stable and strongest form of framing, it supports luan and homasote just fine. 
"If one needs to be crawling up onto the deck, the design has something wrong about it-rofl!"


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## Lemonhawk (Sep 24, 2013)

Milled Homasote is still made <<https://cascaderailsupply.com/pages/frontpage>>
Its easy to use. I use caulk to glue the track to it, but one could still spike the track. I actually used CV ties and glue the ties to the milled homasote roadbed, then glue the rail to the the ties (pliobond contact cement). For me it was an easy work flow. Really emphasizes the importance of the getting the sub roadbed smooth, however or whatever you make it from. My choice of sub roadbed was thin luan ply with a 1/4" foam on top (fan fold siding insulation - lasts forever) then the mill homasote on top, seems to be nice and quiet.


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## NewTexan (Apr 29, 2012)

Plywood is lighter and stronger. I make my tables with plywood and cover that with homeasote (similar to bulletin board material) which deadens sound and is very easy to nail or screw into.


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## CTValleyRR (Jul 26, 2014)

NewTexan said:


> Plywood is lighter and stronger. I make my tables with plywood and cover that with homeasote (similar to bulletin board material) which deadens sound and is very easy to nail or screw into.


Plywood is lighter and stronger than what? 2" extruded foam on L girder joists on 18" centers will hold my 230# weight. And a 4x8 sheet of the stuff weighs less than 2 pounds. If it's strong and light you want, you really can't beat extruded foam. Now, granted, its nail- and screw-holding properties leave a lot to be desired, but I've never been a fan of those types of fasteners.


Fortunately, we're all free to use whatever method of making layouts suits us best!


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## NewTexan (Apr 29, 2012)

If you read the original post, the question asked was which is preferable, plywood or particle board. I think you would have to agree that plywood is preferable to particle board. Some of us prefer wood and similar materials along with nails, screws and rail spikes to foam and glue. Homasote is a great surface for spiking track down. No drilling required, easy to paint, deadens sound. Also easy to cut. Another advantage is that it comes apart easily if you want to make changes later on.


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## sid (Mar 26, 2018)

any body use 5/8's sheet rock . i was pondering this today.


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## traction fan (Oct 5, 2014)

*Sheet Rock?*



sid said:


> any body use 5/8's sheet rock . i was pondering this today.


 sid;

I don't know of any use for sheetrock in model railroading, with the possible exception of backdrops on very permanent large club-size layouts. That doesn't mean nobody ever has, just that I don't know of a case where somebody did
. Sheetrock AKA plaster board, is very heavy, and not very strong. In model railroad benchwork, and in much of this thread, people are looking for strength, rigidity, and light weight in the material they build their layouts from.
So why use a material that's heavy, and can be bent to the cracking point easily? Still, it's your railroad, and you can use sheet rock if you want.


Traction Fan :smilie_daumenpos:


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## Lemonhawk (Sep 24, 2013)

I'm contemplating using 1/4" drywall as sub-roadbed on top of splines. Even possible as the roadbed itself. Its verys solid sounding and takes spikes, although I would probably use caulk. The 1/4" stuff is very flexible vertically. It may require painting.


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## 65446 (Sep 22, 2018)

Tommy, do not use particle board..If HO use 1/2", 5 layer clear ply..But know this. Two things are a nuisance. Unless you plan to use cork or foam roadbed (later ballasted), spiking track directly to ply is a crap shoot. Sometimes spike goes right down in. Other times due to the hard glue between the layers, the spike will bend while inserting it..This can waste a lot of spikes and time..But at the same time, real yard track is right down on the ground with no shouldered ballast..Here it's best to glue track down. Other prob is it's really hard to depict drainage ditches alongside track, trying to dig into the ply..You usually have to skip making ditches with ply SubRB..(not to be confused with Arbee's subs) or do go with 2"extruded foam SRB. M


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## sid (Mar 26, 2018)

well its on most every bodys ceilings in there house and its supported by nails or screws and the studs witch they are fastened too are in fact 24 inches apart they dont sag at all. so i was just thinking thats ya its haevy but its also cheaper and it dont sag as many may say. look up at your ceilings. just a thought . im gunna try it as i have some extra sheets. ive read that it wont handle a lot of water but it will handle what we do to it and if its painted first then it should be no problem at all. as far as strength from what ive seen you guys building tables out of there is no way that it would could break with the little weight we put on them. just thought about it. hahahahahahahha


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## Lemonhawk (Sep 24, 2013)

Keep in mind how drywall is cut. A little cut on one side and then you hit it and it breaks! That's its problem if used to span between mounting posts. The thick stuff does not bend well.


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## CTValleyRR (Jul 26, 2014)

sid said:


> well its on most every bodys ceilings in there house and its supported by nails or screws and the studs witch they are fastened too are in fact 24 inches apart they dont sag at all. so i was just thinking thats ya its haevy but its also cheaper and it dont sag as many may say. look up at your ceilings. just a thought . im gunna try it as i have some extra sheets. ive read that it wont handle a lot of water but it will handle what we do to it and if its painted first then it should be no problem at all. as far as strength from what ive seen you guys building tables out of there is no way that it would could break with the little weight we put on them. just thought about it. hahahahahahahha


The problem is that the drywall in your ceiling isn't supporting anything beyond it's own weight. When you start adding weight to it, it will definitely sag, especially if you use water-based solvents to glue stuff down.


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## Old_Hobo (Feb 20, 2014)

Drywall is the last thing I would use......


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