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osb sub roadbed

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osb sub roadbed
Posted by sktrains on Friday, February 16, 2018 9:12 PM

Hi everone, im new to the form and was looking to see if anyone else used OSB and if so how did it work out for them 

My new layout is about 10x16 and its a combination of the 1/2 inch osb with 1inch and 2 inch foam glued on top depending on the scenery , the inclines and hidden track areas have no foam. The areas with foam are pretty solid but the other areas seam to have a little flex, they are cockie cut out of the osb and  are about 3 inches wide and supported about every 16 inches. I was debating if i should replace them with plywood or reinforce them before i lay the track

THANKS 

Steve   

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Posted by hornblower on Monday, February 19, 2018 3:11 PM

I would predict that you'll be very disappointed with the long term performance of OSB.  Since it is made up of various small pieces of scrap wood laminated together into a sheet product, it does not have the uniform strength qualities of true plywood.  It was designed for use as cheap shear paneling in wood framed structures.  In other words, its strength is resisting compression and elongation movement across the face of the panel.  It was never meant to support loads against the panel face (as in a floor or table top). The surfaces of OSB are not as smooth as plywood either. 

You might get lucky and have OSB sheets that are relatively strong across the length of the sheet.  However, it is more likely that the OSB you have has multiple hidden weak spots that won't surface until after you have completed your benchwork.  Such failures would likely result in "mystery" kinks in your trackwork that eventually get bad enough to derail trains.  Moisture from scenery material application could also damage the OSB.  Even cheap "big box" store plywood would be a better choice.  

Your benchwork is the foundation of your model railroad.  As with any foundation, it is not the place to save money!

Hornblower

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Posted by mbinsewi on Monday, February 19, 2018 4:06 PM

With 1/2" OSB, working with a full sheet, or even 2' wide pieces, it needs to be supported every 16".

When you cut into strips, 3" wide, as you have noticed, it's pretty unstable.  I'd use plywood.

Mike.

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Posted by ROBERT PETRICK on Monday, February 19, 2018 4:26 PM

hornblower

I would predict that you'll be very disappointed with the long term performance of OSB.

I agree. OSB might look strong, but it isn't. Pick up a 3" wide piece in your hand and give it a twist. It'll crumble. And even with support at 16" centers, it's likely to sag as well.

Go with plywood. You'll be happy you did. 

Robert

LINK to SNSR Blog


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Posted by RR_Mel on Monday, February 19, 2018 5:22 PM

 My layout is 10' x 14', I built my helix 28 years ago from 3½" wide ¼” OSB and I haven’t had any problems with it.  I braced it every 12” with 1" x 2" furing strips and it’s glued and screwed.
 
Early on my garage (my layout area) wasn’t totally insulation and the garage would be well in to the hundreds in the summer.  During winter the temperature would drop in to the low 30°s, a 70°+ temperature swing.  I have since added R30 insulation and the temps now are between the upper 50°s to low 80°s.  The OSB has remained the same as built 28 years ago.
 
 
 
Mel
 
Modeling the early to mid 1950s SP in HO scale since 1951
  
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by floridaflyer on Monday, February 19, 2018 5:58 PM

Going into year 13 with OSB. Is plywood better, yes, will OSB do the job, again yes. 

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Posted by sktrains on Monday, February 19, 2018 6:15 PM

Thanks, I'll  go plywood, to change it now is not a big deal to change it later would be a nightmare. I would rather be safe than sorry  

Steve   

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Posted by rrinker on Monday, February 19, 2018 6:37 PM

 I've often wondered this - why people say OSB will sag in model railroad use yet it works fine as a house floor underlayment....

                                --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by CGW121 on Monday, February 19, 2018 7:28 PM

I had a bunch of 3/4" osb left over from a flooring project that I used no problems what so ever

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Posted by mbinsewi on Monday, February 19, 2018 11:40 PM

CGW121
I had a bunch of 3/4" osb left over from a flooring project that I used no problems what so ever

The OP was referring to 1/2", a huge difference with OSB.

And he was cutting it into 3" strips for the "cookie cutter" part. Sure, it will work, as Mel used it on his helix, but it needs extra support, especially if he is going to nail his track down.

I used 1/2" OSB on my garage walls, and 5/8" on the roof. No problems.

And as Randy states, it's used as sub flooring, but usually in potential wet areas, like in front of entrance doors, kitchens, and bath rooms, in Wisconsin anyway, plywood is used.

When it gets wet, or just sits around for a while, unused, and unprotected, it expands.

Mike.

https://www.apawood.org/osb

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Posted by hon30critter on Tuesday, February 20, 2018 3:19 AM

rrinker
 I've often wondered this - why people say OSB will sag in model railroad use yet it works fine as a house floor underlayment....

Well, not always. My SIL owns a nice house with OSB flooring. The main floor has been fine, but the upper floor has had to be replaced. The main floor was covered with hardwood and ceramic tiles with subflooring. The second floor was carpet on OSB. Before they replaced the OSB I had to walk very carefully because the floor sagged significantly under my weight. It actually felt like the carpet was holding my weight rather than the OSB. Eventually somebody (not me) put their foot right through the floor.

As for using OSB for roofing, when I sold roofing I had to give a lot of people really bad news about their OSB roof. Under perfect circumstances it survived the Canadian climate. Under less than perfect conditions it would add 50% to the cost of the roof because of the deterioration of the original OSB.

My position is this: You are spending a lot of money to build your layout. Why take a chance on OSB when the price difference between OSB and decent plywood isn't that huge. So you save maybe $200 by using OSB. Fat lot of good that will do you if your $4000+ layout starts to fall apart down the road. It sure as heck is going to cost you more than $200 to fix the problem. Never mind the time and frustration involved.

Why take the chance? You get what you pay for! I want to spend my time running trains, not fixing the layout.

My 2 Cents

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by CGW121 on Tuesday, February 20, 2018 8:24 AM

mbinsewi

 

 
CGW121
I had a bunch of 3/4" osb left over from a flooring project that I used no problems what so ever

 

The OP was referring to 1/2", a huge difference with OSB.

I dont think 1/2 plywood is all  that much better to be honest 5/8 as a minimum.

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Posted by riogrande5761 on Tuesday, February 20, 2018 8:56 AM

I've used nominial 1/2 inch OSB on 3 layouts now and had no trouble with it.  Many others have said the same.  A few warn against it but I haven't seen any actual cases where they said they had sagging for example, just that they say it will.

One thing I have noticed is that plywood is MUCH more expensive.  If money is no object, then sure, buy high grade plywood.  If you are on a budget, 1/2 inch OSB seems to do the job well.

YMMV

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by rrebell on Tuesday, February 20, 2018 10:53 AM

Personally I just used 2" beaded foam, no problems but no open space was more than  22"x15" aprox.

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Posted by jjdamnit on Tuesday, February 20, 2018 11:02 AM

Hello all,

The only problem I've had with OSB is the weight.

I replaced the 4'x8' sheet of 5/8-inch OSB with 1/4-inch C/D plywood with 1"x4" supports on 33-inch centers.

There is 1-inch blue foam over this sub-layer.

The weight savings was significant and it also allowed some under pike access as it sits on top of the bed in the computer/spare bed/train room.

No sag problems with the new substructure.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by carl425 on Tuesday, February 20, 2018 12:38 PM

riogrande5761
One thing I have noticed is that plywood is MUCH more expensive.

At Home Depot, a 4/8 sheet of 19/32 BC plywood is $31.97.  A 4/8 sheet of 19/32 OSB is $19.87.  If your layout needed 3 sheets, that's a whopping $36 difference.  When a single 20 car train with 2 diesels can easily cost $1,000 or more, I find it hard to look at $36 as a big deal.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by bearman on Tuesday, February 20, 2018 1:08 PM

RR_Mel
My layout is 10' x 14', I built my helix 28 years ago from 3½" wide ¼” OSB and I haven’t had any problems with it.  I braced it every 12” with 1" x 2" furing strips and it’s glued and screwed.   Early on my garage (my layout area) wasn’t totally insulation and the garage would be well in to the hundreds in the summer.  During winter the temperature would drop in to the low 30°s, a 70°+ temperature swing.  I have since added R30 insulation and the temps now are between the upper 50°s to low 80°s.  The OSB has remained the same as built 28 years ago.  

Mel, I am amazed.  You get away with stuff that I would not consider in the least.  I am totally impressed.

Bear "It's all about having fun."

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Posted by sktrains on Tuesday, February 20, 2018 7:38 PM

Thanks all for the suggestions, for me it was'nt about the cost I have about 10 sheets of the osb and a dozen sheets of the 2 in foam leftover from a job and figured if i could use some of it why not , but I got a piece of 5/8 finished ply from depot today and ripped a couple new 3 in strips out of it and can definitly notice a diffrence at that width   

STEVE    

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Posted by BobPombrio on Sunday, March 4, 2018 12:20 PM

I read all of the reply's and I found them interesting to say the least.  BUT I just checked prices at Lowe's and a 4x8 sheet of osb 7/16 is 15.25 and a 4x8 23/32 (3/8) sheet of plywood is 32.58.  So at a 50% saving I would use the USB, I have done a lot of work for OSB in the past and it will support the weight of a tack just fine with 16" on center supports.  What are you placing on top of it? 500 pounds of weight?  The down side to OSB is that it does not like moisture.  But I'm pretty sure we are not running our trains out in the rain or in the pool room.  I will use 7/16 OSB with 2+ inches of foam board on top of that.  Hell if I build a helix I'll use just 2" foam board.  It's not like you will have a lot of weight on it at one time and it will be supported as necessary.  If my helix was really wide, say 6+ inches then I'd use a different material but let's be reasonable here folks.

 

Oh and by the way there is a glue side to OSB that is pretty water resistent as well.

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Posted by SeeYou190 on Tuesday, March 6, 2018 5:50 AM

carl425
When a single 20 car train with 2 diesels can easily cost $1,000 or more, I find it hard to look at $36 as a big deal.

.

Yes When it comes to the mechanical (including benchwork) parts of the layout, do not scrimp.

.

Find somewhere else to save money. Benchwork is too important.

.

I only have used 3/4" birch plywood for my last three layouts.

.

Overkill: Yes!

Problems: None!

.

-Kevin

.

Living the dream.

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Posted by riogrande5761 on Tuesday, March 6, 2018 6:29 AM

carl425
 
riogrande5761
One thing I have noticed is that plywood is MUCH more expensive. 

At Home Depot, a 4/8 sheet of 19/32 BC plywood is $31.97.  A 4/8 sheet of 19/32 OSB is $19.87.  If your layout needed 3 sheets, that's a whopping $36 difference.  When a single 20 car train with 2 diesels can easily cost $1,000 or more, I find it hard to look at $36 as a big deal.

The only flaw in your argument is I didn't pay$19.87, I paid about $8 for my 4x8 sheets in my local Home Depot.  Yeah, difference is a lot bigger.

Kevin, I have built 3 layouts now and used OSB and had no problems like a many of the other responders here.

I'll just say, I have noticed a lot of people with opinions, and as we know, like noses, everyone has them, but has anyone actually used OSB and had a bad experience?  And I'd like to point out that one bad experience is statistically insignificant - there needs to be a preponderance of evidence.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by Doughless on Tuesday, March 6, 2018 8:37 AM

BobPombrio

I read all of the reply's and I found them interesting to say the least.  BUT I just checked prices at Lowe's and a 4x8 sheet of osb 7/16 is 15.25 and a 4x8 23/32 (3/8) sheet of plywood is 32.58.  So at a 50% saving I would use the USB, I have done a lot of work for OSB in the past and it will support the weight of a tack just fine with 16" on center supports.  What are you placing on top of it? 500 pounds of weight?  The down side to OSB is that it does not like moisture.  But I'm pretty sure we are not running our trains out in the rain or in the pool room.  I will use 7/16 OSB with 2+ inches of foam board on top of that.  Hell if I build a helix I'll use just 2" foam board.  It's not like you will have a lot of weight on it at one time and it will be supported as necessary.  If my helix was really wide, say 6+ inches then I'd use a different material but let's be reasonable here folks.

 

Oh and by the way there is a glue side to OSB that is pretty water resistent as well.

 

I always thought OSB was specifically designed for sheething on houses, both as walls and roofs; therefore, its takes nailing well enough and it's water resistent since there are often heavy rainstorms during the construction phase.

Generally:

I think any wood product can be used as subroadbed as long as it has frequent support from underneath.  It really isn't that much more labor intensive to support something every 12 to 16 inches than 24 inches once you get rolling with the saws and power screwdrivers.

Especially if your benchwork design allows for a 1x board to be used as a lengthwise spine to provide rigidity.

- Douglas

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Posted by RR_Mel on Tuesday, March 6, 2018 10:18 AM

bearman

 

 

Mel, I am amazed.  You get away with stuff that I would not consider in the least.  I am totally impressed.

 

Bear
 
The reason I went with the OSB to make my helix is I’m a tightwad.
 
I knew there was going to be a lot of waste no matter how I cut up the helix roadbed and I just couldn’t waste good plywood like that.  I laid out the helix on my CAD and made all of the 1” x 2” supports per my drawing as well as the large cookie cutter style OSB roadbed.
 
I made a ¼” dado cut a ¼” deep in each support for the OSB.  I anchored the supports to the ½” layout top by drilling a screw hole from the top and running the screw up from the under side.  I used Elmer’s Carpenter glue to secure each support to the plywood.
 
Actually the only thing that ended up being a problem was the hardness of the OSB over regular plywood.  After gluing the cork road bed to the OSB and started laying the track using track nails I couldn’t get the nails to go into the OSB without pre-drilling each hole for the nails.
 
I didn’t anchor the OSB in the supports, the notches were somewhat tight and to this day everything is still as built in 1989.
 
Back then I didn’t have a digital camera so I don’t have any pictures of the construction of my layout and the helix is 80% covered by mountainous terrain.
 
Twenty nine years later I’m still working on the scenery around my helix.
 

 
The picture above was taken in February 2014, still in progress.  A layout is never finished, I hope to call my layout finished before I’m pushing up grass.  I have aproximately two square feet left before I can call it finished and it's ballasting, I hate ballasting!
 
 
Mel
 
Modeling the early to mid 1950s SP in HO scale since 1951
  
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by UNCLEBUTCH on Tuesday, March 6, 2018 10:49 AM

SeeYou190
 
carl425
When a single 20 car train with 2 diesels can easily cost $1,000 or more, I find it hard to look at $36 as a big deal.

 

.

Yes When it comes to the mechanical (including benchwork) parts of the layout, do not scrimp.

.

Find somewhere else to save money. Benchwork is too important.

.

I only have used 3/4" birch plywood for my last three layouts.

.

Overkill: Yes!

Problems: None!

.

-Kevin

.

 

 With all due respect; I disagree. I built all my layouts with recycled,reused,leftover scraps. Lumber,foam and even the wireing came from dumpsters. Method is more inportant then materials.

I don't use OSB, only because I prefer foam.

Cost; Very low

Problems; None

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Posted by ATLANTIC CENTRAL on Tuesday, March 6, 2018 5:57 PM

I built part of the upper deck of my multi deck layout with OSB, two layers of 1/2, laminated with construction glue. these were narrow shelves suspended from an angled attic ceiling.

The OSB sandwich is screwed to a 2x3 ripped with a 45 degree angle for the sloped ceiling, and hangs from the pieces of 2x4 you see in the photo. The total width of the OSB is about 16", the "visable" part in from of the 2x4's is about 8 inches, there is a 1x2 edge piece behind the wood paneled fascia. Everything is assembled with screws.

In this particular application, it has worked fine for nearly 20 years. 

For larger areas on the lower levels I used 3/4" birtch plywood.......

It is all about understanding proper support spacing. I'm not going to give a lesson tonight...........

Sheldon

    

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Posted by Doughless on Tuesday, March 6, 2018 6:24 PM

UNCLEBUTCH

  Method is more important than materials.

That sums it up, really.

- Douglas

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Posted by SeeYou190 on Wednesday, March 7, 2018 7:06 AM

riogrande5761
Kevin, I have built 3 layouts now and used OSB and had no problems like a many of the other responders here.

.

Some people do engine repair without using a torque wrench and have no problems also. It does not make it good advice or the correct thing to do.

.

I know several people that wired their layouts with old telephone wire. They were successful, still not a good idea.

.

OSB has many disadvantages and should not be recommended. Good quality plywood is a better choice. The only advantage to OSB is price.

.

I am glad you have not had problems with your layout that could have caused you to become discouraged with the hobby.

.

-Kevin

.

Living the dream.

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Posted by ATLANTIC CENTRAL on Wednesday, March 7, 2018 7:58 AM

SeeYou190

 

 
riogrande5761
Kevin, I have built 3 layouts now and used OSB and had no problems like a many of the other responders here.

 

.

Some people do engine repair without using a torque wrench and have no problems also. It does not make it good advice or the correct thing to do.

.

I know several people that wired their layouts with old telephone wire. They were successful, still not a good idea.

.

OSB has many disadvantages and should not be recommended. Good quality plywood is a better choice. The only advantage to OSB is price.

.

I am glad you have not had problems with your layout that could have caused you to become discouraged with the hobby.

.

-Kevin

.

 

Kevin,

Again it depends a lot on the methods as well as the materials.

I have wired some layouts with telephone wire, in fact my own DC Advanced Cab Control System w/radio throttles makes extensive use of CAT5 cable for control wiring for the several hundred LED push buttons and 24 volt relays that control my cabs, signals, turnouts and more.

I don't use it for the power to the track.........

I would never use OSB to sheath a large area of a layout, I'm with you on that, nice birtch plywood, but two layers of OSB worked great for my 16" wide shelf.

I won't use cork or foam roadbed, but that stuff works great for lots of people - too soft for my taste or way of building.

I do use a torque wrench, build more engines than I can remember back in the day........

Sheldon

    

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Posted by rrinker on Wednesday, March 7, 2018 8:04 AM

 I've had many of the problems people insis don;t happen with homasote - the last N scale layout I built on homasote, I took completely apart, track AND cork, with no tools because the nails pulled right out. That to me is not "spike holding". When it got damp, the edges swelled terribly, yet even the Homasote company says you can put chunks in a bucket of water and nothing happens.

 I once built a shelf layout with something I've not seen available since, some sort of HDF material. Even an 18" wide strip, 4' long, was VERY heavy, much more than any MDF. It's not soo much the layout, but above the layout, on the same steel verticals, I added another shelf where underneath I put lights for the layout and on top, I lined up my already large MR and book collection - FAR more weight than any layout. Not the slightest sag, and I wasn;t even using the newer double rail brackets, just the stamped single rail ones, although I did use the heavy duty verticals, not the cheap ones, so it wouldn;t get crushed in. This is yet another material that falls under the "Oh, it will sag if you use it like that" category. Nope. If you had problems with OSB, either it was already dmaaged before use or it was some cheap CHinese junk. Notice in Sheldon's picture the roof of his layout building even uses it for sheathing. Clearly it can stand expected wind and snow loads, otherwise the inspector would never have approved it for occupancy. It's used for subfloor in homes as well as exterior sheething. Floors where people bring in heavy appliances like ranges, refridgerators, and dishwashers. Why can it handle such static loads (plus the dynamic load of people walking across it) but not 5 pounds of trains? Makes no sense.

                                              --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by ATLANTIC CENTRAL on Wednesday, March 7, 2018 8:52 AM

Randy, to be fair, the osb you see in my photo is interior sheathing in place of drywall, it is not the roof sheathing. But there are a number of floor/roof rated products similar to osb, and typical 7/16 osb sheathing is easily as strong as the 3/8 plywood I've seen used on more than one layout.

More later......

Sheldon

    

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