Do humble bundle codes expire?

NOPE

Not for the forseeable future apparently

I don't think they expire

No, but the world might end tomorrow for all we know so I'm not sure.

Thanks for the comments ill give them away now.

Here are some links for those who want the game and DLC

http://www.steamgifts.com/giveaway/qhCdG/red-faction-armageddon-path-to-war-dlc

http://www.steamgifts.com/giveaway/vU9GN/titan-quest

Short answer: Not in the forseeable future.

Long answer: The keys should be good as long as things such as electricity, internet, steam, and humble bundle exist and work.

no(well not that I'm aware of(and if they did they'd have to say so somewhere I'd imagine(tbh really I'm only still typing to test a theory on karma(that if I keep using parenthesis I'll keep breaking my posts so nobody can read what i say) by attempting to trigger the Buddha's smiting wrath(or however karma works))))