Homasote overhang question

Walt- I don't think more than a foot or so for an overhang. If the board is between two supports and unsupported in the middle then it could probably span a couple of feet. It depends on the weight obviously so if you can do some testing now you could see how far you can go. I haven't used homasote for a train table since my first layout when I was a kid.

You could stiffen the board by adding a strip of wood to the bottom along the outer edge too.

There is always a temptation to lean on the edge of your table work to reach something.  I would add something to stiffen it that is connected to the main table work.

A usual I didn't supply enough info.  Even tho' not the exact situation, picture this.  I have a 3'10" x 3'10" piece of "benchwork" (acually I do and have used it for years with a 1" overhang around the perimeter by placing a 4'x4' piece of Homasote on top.)

Now picture this: suppose I wanted to use a 4'x?' piece of Homasote, which would overhang by however much I expanded the "?" beyond 4'.  Say I made it 4'x4'4" that would give me a 5" overhang on the one side.  Realistically I can't support or stiffen it as that would defeat the whole reason that I want the overhang.

So in this example, is 5" too much of an overhang to support one train running over it?

the other concern: this would be in the rear of the layout so there is no chance of leaning on it.

as always, thanks - walt

Walt,

I would not overhang homasote by itself at all. For a few inches, say six or less, a 1/4" plywood under the homasote may be OK. For any more than a few inches with the 1/4" ply, I strongly recommend 1/2" or heavier plywood. The homasote by itself may not break right away if loaded, but it will definitely sag with time.

Good luck!

Alex

Homasote is basically paper. I would not let it hang over, even without the train on it. I have to think it will eventually start coming apart, and with weight on it, it will likely start sagging.

there won't be, can't be, anything under that overhanging part.  

It seems this is hard to picture.  Just a simple, UNSUPPORTED, 5" overhang of 1/2" Homasote.

walt

You would have to try it.  It sounds like you don't fasten the Homasote down since you take it on/off.  In that case, the part not overhanging can flex up a bit when there is weight on the overhanging part.  Try it using a suitable weight.  I do think that over time the Homasote will give - you might have to overhang a different end each time.  If it were mine, I would laminate the whole Homasote piece with 1/4" ply to give it some strength.

Brendan

I agree with Walt.  You would be asking for a disaster.  An inch or two at most if you absolutely, positively have to.  

Sounds like I should give up on my idea since completely unsupported doesn't sound like a very good idea.

Brendan, yes, it's not attached to the "benchwork" but there would be track, structures, etc. on the supported part to hold it down.  I do screw the track down to the Homasote.

As always, thanks - walt

The best way to handle this is to buy the same amount of 4x? plywood. Attach the plywood to the benchwork and the Homasote to the plywood. Then a small overhang like you are discussing would seemingly be sufficient structurally.

Consider a short support system.  Using stubby pieces of 2" X 4"  stand offs and a fascia board with some type of plywood subsurface will provide sufficient  support.

I cut back the Homosote  an 1 1/2 " and butted 4 1/2" of plywood against the existing 1/2" plywood decking over a bead of polyurethane adhesive. 

Then I placed  6" of  Homosote down, overlapping  the existing plywood deck.  Nice firm support for spiking down the new track.  Short cuts can bite you and be expensive in the long run.

Due to an interference fit of operator's torsos and 0 scale trains running on the bump-out  I added a belly button interface protection device.

For a Xmas village display I overhang 1/2” homasote about 1’. However it is framed with 1”x2” furring strips . This has worked for years although no trains on it

I would advise against any overhang, the stuff isn't designed for supporting weight, it is designed to be supported.  You will regret your decision.

Tom Tee posted:

Consider a short support system.  Using stubby pieces of 2" X 4"  stand offs and a fascia board with some type of plywood subsurface will provide sufficient  support.

I cut back the Homosote  an 1 1/2 " and butted 4 1/2" of plywood against the existing 1/2" plywood decking over a bead of polyurethane adhesive. 

Then I placed  6" of  Homosote down, overlapping  the existing plywood deck.  Nice firm support for spiking down the new track.  Short cuts can bite you and be expensive in the long run.

Due to an interference fit of operator's torsos and 0 scale trains running on the bump-out  I added a belly button interface protection device.

Tom,

I like the bbifpd.  I'm gonna have some narrow aisles between 3 peninsulas so that's a great idea.  I'm prob gonna have to put an  a.i.p.d. on the opposite side as well - or start working out.     I'm in total agreement w all the comments about the homasote needing supported.  Planning on using homasote roadbed on the layout we're planning.  Used it in the past and liked it. 

Tom