Drywall Subroadbed

Discussion in 'FAQs' started by ATSF-Loco, Nov 14, 2005.

  1. ATSF-Loco

    ATSF-Loco New Member

    I have been modeling for about 4 years now and have made a few layouts, all open grid construct. And I have used plywood with 2" "blue" foam. I am starting a new HO layout and I am going to try 1/2in Drywall as my subroadbed on an open grid, with no foam. Anyone ever done this, or does anyone see any downfalls?

    P.S. I'm going to use Wood. Scenics risers and inclines for topology changes

    New to the Forum
  2. MasonJar

    MasonJar It's not rocket surgery

    Hi Dave,

    Welcome to The Gauge!

    I see two problems with your proposal. Unsupported drywall is not very strong, so spanning open grid benchwork may be problematic. The other problem is using waterbased scenery and/or ballasting methods may warp and weaken the drywall. A plywood "sub-subroadbed" might address the strength issue, but you'd still have to deal with the water.

    Interesting proposal though - always good to think outside the box, so to speak.

  3. Drew1125

    Drew1125 Active Member

    Hi Dave!
    Welcome aboard! :wave:

    I'm gonna have to go along with Andrew on this one...
    Drywall & water just don't mix, & also, drywall is even heavier than plywood, but with no supporting strength...
  4. ATSF-Loco

    ATSF-Loco New Member

    Well, I did think about all that...sorta....The benchwork is okay it's well supported with 1x4's on edge every 16in like a wall. But, what I didn't think about was the water, hmmm. Okay, more thinking outside the box......I was planning on spackling it like a wall and painting it (like a wall). But.....maybe this isn't such a great idea after all......good ole' tired and true plywood.
  5. MasonJar

    MasonJar It's not rocket surgery

    The pink or blue foam is really the "state of the art" today (although the idea is not that new any more). Adding spackle to the foam for contouring etc, is good though. I use the lightweight variety - looks like a tub of whipped cream. It dries to a sort of solid foam texture that is slightly flexible and very light - a good compliment to the pink foamboard.

  6. Will_annand

    Will_annand Active Member

    I would have to agree with the guys. I would stay away from drywall.
    The pink or blue foam stuff is cheaper than drywall up here anyway. :D
  7. ezdays

    ezdays Out AZ way

    I can think of no positive with using drywall, except maybe the initial cost. Unsupported drywall will not take the weight of someone putting pressure on it, using it as support as they worked around it. It is prone to cracking and not very forgiving and hard to repair when broken. Andrew's point of not taking moisture very well is valid. It is not easily sculptured and you will wind up with a sub-par layout base that will eventually cost you more than if you started out with extruded foam in the first place.
  8. Russ Bellinis

    Russ Bellinis Active Member

    One member of our modular club brought it a test module made with a 1x4 perimeter frame and 1x2 cross members every 12 inches. It used a 2' x 4' peice of luan doorskin for the subroadbed. I was amazed at how strong and light it was. I would never have believed that luan would be strong enough to suport ho scale trains if I hadn't seen this module.
  9. ATSF-Loco

    ATSF-Loco New Member


    Well, I already screwed down and liquid nailed half of the layout with drywall, so I was debating on wether to rip it all up and use plywood or just to leave it and put foam on the top. But I was doing some research :thumb:.....and concluded that drywall will work for me with it primed and a layer of exterior paint all over it (waterproofing)...so I decided to use the drywall after all. I'm still up in the air wether to paint or just top it all with 1/4 foam.
    And rememebr everyone it is not UN-supported it is VERY well supported, just like a wall in your house would be....1x4's on edge every 16"...with cross members on those...(laughing).....I know it's strong cause I stood on it last night...hanging lights...(Me = 195lbs). So I think it'll do........now wether to paint or foam......

    I apologize if I'm being thick-headed

  10. ezdays

    ezdays Out AZ way

    You could get by with the foam, or even a layer of thin lauan plywood, as Russ suggested, would add to the strength. Unless your layout is going to be perfectly flat, you'd be better off with the foam, giving you the ability to carve a few valleys and rivers and add some hills to give your terrain a bit more interest.
  11. ATSF-Loco

    ATSF-Loco New Member

    Yep yep

    I was thinking about that to.....hmmmm....oh and it would probably be much easier to mount my tortose SW machines in foam as well, so my final decision (and I'll shut up) is to tear up the drywall and use 2" foam.....thanks everyone for putting up with me..

    Thanks Again,
  12. Russ Bellinis

    Russ Bellinis Active Member

    This may be obvious, but I've found obvious suggestions are sometimes overlooked when we don't make them. Your Toprtoise machine won't mount to foam, so don't forget to put wood cross members or brackets anywhere you want to mount the Tortoise machine to the benchwork.
  13. ATSF-Loco

    ATSF-Loco New Member

  14. MasonJar

    MasonJar It's not rocket surgery

    Hate to disagree with you Russ, but Dave is right. We have a guy at the modualr club who has installed many (can't recall how many) in his industrial switching set of modules. Simply imbedded in the foam...

  15. jim currie

    jim currie Active Member

    would tend to think that dry wall would act like a sounding board also.
  16. tillsbury

    tillsbury Member

    Whilst that tortoise mount looks extremely elegant -- I wonder how you replace them? I've had two tortoises die after installation, and those look like a bear to get out...
  17. Russ Bellinis

    Russ Bellinis Active Member

    That was the reason for my post on using wood framing for brackets. I never thought of embedding the machines in the foam, but I would be afraid that if I did scenery over the top of the Tortoise machines, I wouldn't be able to access them for repair or replacement. If they were embedded from underneath in the foam, what would keep them from falling? If they are screwed to wood brackets under the layout with a suitable hole for the lever to stick through to work the turnout, they are easily replaced, or removed for repair.

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