Isolating track after ballasting?

[RobertInOntario]

I wonder why not fill the gap with a dab of rtv or silicone sealant, color of your choice. Just wipe off the excess, it would close the gap and still allow some expansion/contraction?

Thanks, I might try that. Still haven't got around to doing this yet, although I've bought the switches. Just need to be in the right mood as I don't want to mess it up! (since the track is neatly ballasted, etc.).