HO roadbed question

[WVrailfan]

I belong to a club building a new 30 X 40 foot HO layout. The bench work is going together as open grid with 18 inch centers on which the roadbed and scenery will be built.

We were planning to use 3/4 plywood, with 1/2 in Homasote topped with cork for the road bed. However, we have an opportunity to purchase 1 inch Homasote at a really good price and now we are debating if we can just use the one inch Homasote with cork for the road bed.

I have a piece of the 1 inch Homasote, it seems as strong, or stiff, as the 3/4 inch plywood, while still being lighter than the 3/4 inch plywood and 1/2 inch Homasote combination.

The biggest fear seems to be how the Homasote will degrade in time. Will it sag after a few years, or will it hold up as well as the 3/4 inch plywood.

Anyone here have experience with 1 inch Homasote or suggestions regarding HO track road bed.

Thanks
Jim

 

[montanan]

Homasote is an excellent roadbed material. There is a product called "Homabed" which I used on my layout starting ober 20 years ago. I used it dorectly on top of the plywood handlaying my code 70 track. It is a great product and I have not had a single problem with it in all the years it has been down. The Homabed is a quarter of an in thick and has beveled edges with slits cut into the edges to all easy placement for curves. When ballasted these slits dissappear. I would recommend this product to anyone.

I would definitely not use the homasote support itself. My layout benchwork is quite similar. Depending on where you are, humidity could effect the homasote. Using the homabed directly on the plywood will have the strength and being that it is glued to the plywood will not warp or bend.

 

[otiscnj]

Homasote needs to be supported by a subroadbed. 3/4" should do nicely. Most people cut it into strips, except for town areas, then paint it, to reduce its tendancy to be sensitive to humidity. If you get it thick enough, you can push the spikes into it, without driving them into the plywood. Homasote holds spikes very well, from when I've used it in the past. Not sure you need the cork on top of the homasote, except for visual effects.

 

[Selector]

Homasote, in all my readings, is meant to be a sound-deadening roadbed. I would not consider using it for sub-roadbed, or without something fairly stiff below it because it absorbs moisture, although most seal it, and it isn't all that stiff compared to plywood.

Also, I think 1" is much too thick. I use 1/2" exterior grade ply and top it with that eco-cork underlay you can get at Home Depot. I cut it into strips wide enough to work as roadbed, glue it to the plywood with DAP Alex Plus with silicone, and then glue the flex track lengths and turnouts onto the eco-cork. Works like a hot damn.

This image shows it. It isn't pretty because it will be inside a helix.

 

[Railfan87]

Agreed. Homasote is an excellent sub-roadbed, but it needs to be supported. Paint both sides before you start using it. I found a recycled latex paint called 'Boomerang.' Sells for under $20 for a 4 litre can. They have a colour called Shore that I'm using as an 'under the scenery' coat.