I disagree completely.
I think Ghost>flash on singed any day.
When you flash it leave a break it his poison trail.
Ghost would be much more effective at running up to them and flinging.
With my build i start with 400+ movement speed at lvl 1.
Unless they waste their flash, They won't be getting away.

The only summoner spells I thing Singed should take is ghost+ignite.

i Really like your idea on this and you prove lots of points. But it's a pretty good debate between exhaust and flash because as you mention, flash could get them by surprise. But if you were to choose between them it would depend on the team, take for example if you are in a ranked game. If they have lots of melee dps you would go for exhaust, however flash would be a very good spell as well and can pick one of them out. As for the movement, i didnt really think much on the mr since force of nature gives plenty mr. but its a very good idea you gave me!

Flash is much more effective for landing a fling than exhaust is. You already have a snare with your mega adhesive. This build relies on the idea that you will be able to fling someone close to your turret early game, which is ok. But as you start going up against more advanced players, they will stop falling for that and your summoner spell will have been wasted. A flash-fling combo will catch them off guard a lot more often (by this I mean flash right on top of them when they're just out of range of the turret. They won't have time to react). It is also needed for avoiding ganks, hopping over walls, etc. For team fights, someone else on the team should have Exhaust for the other team's carry. Overall not too bad of a guide.

I agree that rylai's is a little overrated on Singed, and I think you should include different options for boots, depending on the other team's composition. For example, I see many people pass up on Merc's Treads while the other team is building AP because they like the extra movement speed, but they would get a boost to movement speed anyways from Force of Nature and combined with Merc's, you will also have a ton of MR.
i Really like your idea on this and you prove lots of points. But it's a pretty good debate between exhaust and flash because as you mention, flash could get them by surprise. But if you were to choose between them it would depend on the team, take for example if you are in a ranked game. If they have lots of melee dps you would go for exhaust, however flash would be a very good spell as well and can pick one of them out. As for the movement, i didnt really think much on the mr since force of nature gives plenty mr. but its a very good idea you gave me!

I liked the build but since Singed is a tank i would prefere some gameplay footage on him since everyone got a build exatly like this. The gameplay is always what makes the defience ;P

Sry for my horrible english ;/

I now play singed TY so much

FLing is not your main source of damage - your poison is. Max that first instead of the mix you are doing.

Good build. I will recommend this build to my friends playing Singed :D. (i dont even play him xD) just messing around on mobafire.
you play on EU?
add "ossish" and we play for sure :D