LAYOUT CONSTRUCTION

[Wayne II]

BUILDING A LOGGING LAYOUT, 1920-1940'S ERA.  FOR THE YARD AREA, SAWMILL AREA, TOWN AREA CAN I JUST USE 1/2" HOMOSOTE ON TOP OF 1/2" PLYWOOD AND THEN LAY FLEX TRACK ON TOP OF THAT?  THEN EASILY SCENIC BETWEEN THE TRACKS.  OR DO I HAVE TO USE A RAISED TYPE OF ROADBED?  FROM PICTURES IN BOOKS OF OLD LOGGING RAILROADS THE TRACK LOOKS FAIRLY FLAT, NOT MUCH RAISED ROADBED.  THANKS

WAYNE II

[BigDaddy]

to the forum.  In all the internet forums in the known universe, typing in all caps is considered SHOUTING

Yes you don't need roadbed in a yard area.  Some people may quibble about the thickness of your plywood. 

 

[SpaceMouse]

BigDaddy

Some people may quibble about the thickness of your plywood. 

The issue here is sagging and warping. The determining factor is the distance between your supports and the quality of your plywood. Cheaper plywood tends to be more prone to losing it's shape than exterior grades and or hardwood venier plywoods. 

[UNCLEBUTCH]

 I do not use a roadbed,no issues

Why not use 2'' foam, instead of plywood and hom. You could lay the track right on it, and be able to cut your pond,ditches ect.

[hon30critter]

Hi Wayne:

Welcome to the forums!!      

If you are going to use plywood I would suggest using 3/4". Even then you will still get some expansion and contraction as the humidity changes.

Our under construction club layout is constructed with 1/2" Homasote over 3/4" G1S plywood. We noticed a little bit of track movement when the track was first nailed down in February. Since then the problem seems to have mostly gone away. We are using cork roadbed too, but as others have said, the cork is not necessary. We are doing it for profile as much as to quiet the track sounds.

If I were doing it again, I would use 3/4" Baltic Birch 11 ply or 13 ply furniture grade plywood. It is more stable. It is also more expensive, but if you consider how much you are going to spend on what goes on top of the plywood and Homasote, I think it is worth the expense. Why invite problems?

One thing to note is that you can cut into the Homasote with a carpet knife (box cutter) to create ditches. It takes a few passes and a bit of effort, but it is quite doable.

Dave

[Wayne II]

Sorry about the all caps, will watch that in the future.  I gather you think I should use thicker plywood, which would not be a problem?

[Wayne II]

I was thinking about using a 14" space between cross pieces? I seem to gather that 1/2" plywood is not thick enough?

[Wayne II]

Not personally familiar with the foam, but have seen it in some articles. My father had a layout many years ago and that was 1/2" plywood and then 1/2" homosote. In looking at different articles I see that is still around and was just figuring on using that. Not that I couldn't use foam. This portion of the layout will be attached to a wall, 27" in width. I figured 14" between cross pieces.

[Wayne II]

Shouldn't have too much of a humidity problem. From what I'm hearing in the posts the 1/2" plywood doesn't seem to be thick enough. I was going to use crosspieces every 14" or so, but can easily go with a thicker plywood. This portion of the layout will have one side attached to a wall, and will be 27" wide

[UNCLEBUTCH]

IMHO.

1/2 in ply is more then enuff to hold up a couple pounds of plastic,on 14in OC you could even go to 16inOC.Your support frame is more inportant then the material on top.

I'm a firm believer in foam. 2in over open box frame will take anything you can put on it.

Cabnet grade plywood is nice, if you got the money. But you don't need it.There are other,cheaper ways to get it done.

Do what your comfort level allows,do not let the ''over thinkers''overwhelm you

[mbinsewi]

I think the 1/2" plywood would be fine, with the supports at 14"o/c, or maybe 12" o/c if you are worried.

I'd just make sure it was all fastened together good, with screws.

Mike.

[Wayne II]

Thanks

[PED]

I used all 3" foam with no plywood under it. About 12-14" between supports and I have not had any sag problems.. Main reason I can think of for an underlayment of plywood is if you need to attach stuff like like turnouts motors to the underside. I used all Kato Unitrack turnouts so I did not need to attach anything under the foam.

A big benefit of thick foam is that you can carve depressions in it (ditch, etc) if needed.

[railandsail]

SOUND

When I was considering foam for my subroadbed, I read quite a few forum postings on a number of forums. Basically it appears that 2" form is perfectly adequate for strength even between 24' supports.

There were a number of questions about how it transmitted sound, and there were a number of observations that this could be significantly reduced by adding a thin (even 1/8 wood) skin to the bottom side of the foam. Naturally this would assist with 'attaching' items to the underside.

[SpaceMouse]

Wayne II

From what I'm hearing in the posts the 1/2" plywood doesn't seem to be thick enough.

I'm using 1/2 inch plywood with about 20" centers--but I'm using high grade plywood with glue that resists deterioration from moisture. If you buy the cheap stuff off the rack at Home Depot, you need to go with your 14" OC supports or less. 

 

[bearman]

I have had no issues with 1" foam on 1/2" plywood and the benchwork is 10 years old.

[willy6]

I have a 21' x 8' layout with 1/2" plywood topped with 1/2" foam on 2" x 4" benchwork with 20"centers and it held my 217 lb body when I installed my track lighting.

[Wayne II]

Thanks for the info Wayne