Hi all, I'm just getting into model railroading after finishing university and finally having a little time on my hands (but no money...). I used to have an old Life-Like HO set when I was much younger and spent heaps of time mucking around with that. I'm finally about to build my first real layout and have been wondering what are the real benefits of using underlay? Is it just because of noise? Or does it help with the actual running of the trains? I'm still not really sure of what to use or why I should, such as cork or foam. I've got a massive roll of "zipped expansion jointing" foam, it's normally used for the divides between concrete slabs. I think it might make good underlay... any input as to what the benefits are and what the best materials are would be great! Thanks, and sorry I might end up asking many more strange questions!
Cork or foam (or any other material) roadbed (what you're calling "underlay") is nothing more than a scenic element, and has nothing to do with the performance of a layout.
Look at the grade of any real railroad mainline (and some spurs) and you'll see that the track is always raised up above normal ground level. Usually, there are more than one level of roadbed under a ROW, which helps aid in draining water off the track surface. The cork roadbed sold for our hobby is a way to replicate that real roadbed profile, and as such is scenery. Important scenery if you care about how your layout looks, but scenery nonetheless.
Ray Breyer
Modeling the NKP's Peoria Division, circa 1943
Greetings, and welcome to the forums.
When I read your title I thought you were referring to my favorite roadbed material, fan-fold underlayment (a thin extruded foam product used under vinyl siding.)
While roadbed might make some small contribution to quieting the train-on-table noise, it is primarily a scenic element, one of those small things that separate toy trains on a table from an honest attempt to model the looks of a full-size railroad.
You might want to experiment a bit before committing to large-scale use of the product you mentioned. It might be satisfactory, or it might not. Various threads on this forum have mentioned a variety of roadbed materials; you might want to enter "roadbed" in the search block and see what turns up.
Chuck (modeling Central Japan in September, 1964)
From the far, far reaches of the wild, wild west I am: rtpoteet
Welcome to the forums!
As others have pointed out, it's mostly a scenic element, but it does help to quiet things down too.
As for foam, many people use fairily thick foam so that they can carve down into it for scenic features below track level once they've laid the track. For yard areas and areas like the praries (thought it's not as flat out there as one might think) you can use thinner foam as you woun't be doing so much carving.
The foam that you're talking about.....is that the stuff thats like 1/4" thick and comes folded, like in this pic? http://i83.photobucket.com/albums/j319/pcarrell/Autumns%20Ridge/7-22-074.jpg . If so, I've used a bunch of it for my interchange area and my staging yard. It works great for that. I'll use 2" foam for most of the other areas though.