I don't think fire salamanders can climb glass at all. However it certianly doesn't hurt to have a screen top, at least to keep other household pets or children outside of the cage. I personally am not all that familier with fire salamanders so did a bit of research and found some basic care info for you. They seem to be more burrowers than climbers so a lid may not be necessary, providing the cage is high enough it can't reach the lip while leaning against the side or on cage furnature.
www.reptileallsorts.com/firesalamander cj-cs.htm
www.redeyedtreefrog.com/Fire_Salamanders/fire_salamanders.html
mike-edwardes.members.beeb.net/Amphibiary/Salamandra.html
There is also our sister site forums to check as well, though I am loath to recommend people going there, as I perfer my fellow Canadians stay here and post often to get the Canadian forums more busy, the US site does tend to be more busy.
forums.kingsnake.com/forum.php?catid=26