As you're probably already aware, all roulette tables have a betting limit and once you reach this limit you'll no longer be able to increase your stake. This is a particular problem when playing with roulette systems that use an unlimited progression factor.
What are the betting limits?
The limits are put in-place by the casinos and can vary between each one, however you shouldn't expect the limit to exceed £300 on a £1 minimum stake table.
Problems with the martingale roulette system:
If you've never heard of this roulette system before, then you can read about it in the free roulette systems section.
Martingale system uses an unlimited progression factor which simply doubles your stake cost on every losing spin, and this is very dangerous for your pocket.
After each losing spin you double your stake for only £1 potential profit, and once you hit that tables betting limit you're quite simply... screwed! Maybe you think that the £300 limit is far far away and you won't possibly reach it, well you'll be surprised because this is how quickly it can happen: 1,2,4,8,16,32,64,128,256,512 . See, all it takes is 9 losing spins in a row and you'll be toast.
How to not reach the table limit:
The best advice anyone can give you is just to stay away from progressive systems, or at-least systems with unlimited progression.
This site has loads of free roulette systems which only use flat betting patterns, if you stick with these you won't need to worry about those evil table limits.
Also:
If this article interested you then read the money management article.