No fermentation after 12 hours

last night i made a small 3.5 gallon partial mash batch of IPA and today there is still no visible fermentation, no krausen or bubbling in airlock. all other brews ive done before took off within a matter of hours.
i used a cheaper dried yeast that i bought only a few months ago. would it have gone out of date? i rehydrated it and everything. how long can i leave the wort in my carboy before pitching a new yeast packet?

also there was this weird white stuff in suspension just after i had filled from kettle into carboy and ive never seen this before, also being just as sanitary as always. would this be due to using irish moss or the large hop rate of the IPA?

Thanks

12 hours is too soon to worry - it can take quite a while to get going. It's possible that it was out of date, but I wouldn't write it off yet. As for stuff in suspension, could it just be break material?

well i used a small amount(200g) of honey in the brew just for fun maybe that caused the stuff in suspension. anyway it's all fallen the bottom of the fermenter now.

is it ok to leave a repitch if neccessary after a long time, like could i wait another 3-4 days because im busy this weekend? as long as the wort is safe inside my carboy it wont go off right? assuming it doesnt kick off before then.

Just wait it out.

Ive let the wort set for about 2 days before i could get more yeast. Everything turned out ok. Just as long as nothing can get to it. You should be alright. But dried yeast usually takes a while to get going.

RDWHAHB dude... seriously...

yeah i know you're right its just never taken this long before so il just wait it out.

by the way im getting excited about moving to allgrain. ive just cut a hole in the top of my keg and my uncle next door has a big burner on a stand which i can use, ive got a cooler which il convert into a mash tun and a wort cooler.