Before you try nails of glue, try Suretrack Clips to hold your track together.

When I first considered a train set for my son, the thought of having to put the tracks back together again every twenty seconds was daunting.  I noticed that most of the toy store train sets were glued together or nailed down.  I considered doing that.  Luckily I didn't.  Firstly, your resale value goes out the window.  Genuine Thomas tracks keep a very high percent of their purchase price, and even generic still resells easily.  But if it's glued down, it's even hard to unload on Craigslist. 

Secondly, when your child is very young, say under 2 1/2, a stationary set is great.  But when they get older, closer to 3 1/2, they'll want to build their own sets over and over again.  So before you glue, before you nail, consider SureTrack.

For building spiral layouts, for building elevated layouts, or building anything with a younger sibling,  the Suretrack clips are a Godsend.  They aren't a 100% panacea, but they really help.  I have a 3 year old and a 1 year old. I call the one year old lots of nicknames, among which Mayhem and The Deconstructionist are my favorites.  He loves to destroy whatever we build.  These clips keep things together.  He can still rip the tracks apart, but it slows him down substantially.  What he used to be able to trash in 5 minutes, now would take him a lot longer.  And even then he can only destroy one section at a time.

The only downside is that they are slightly homely.  But for those of us who really need them, the tradeoff is welcome.  They fit best on generic track, like Imaginarium or Orbrium, etc.  Genuine Learning Curve Thomas tracks are slightly wider and thus a little harder to et the clips on.  I've heard that these clips can stretch and become looser over time. I have a feeling that those complaining of this were using Thomas tracks.  I usually start securing the generic pieces first and then do the real Thomas track last.  We bought two packs and that would be plenty for most people, but I think we need one more set if we'd want to secure every single piece in some of our larger layouts.