Question
Is there a spray/chemical that you can paint on the wall to impede the sucker growth of Ivy, I have a full wall of Ivy and I need to pull it back several times a year around the windows etc, is there something I could paint on?

Answer
I previously suggested the use of paint mixed with a chemical called Treflan.  i frankly don't know if this will work, and unfortunately, I really don't have any other ideas for slowing the roots of this very vigorous plant.  

There are some interesting ideas at

http://www.noivyleague.com

Their primary goal is Hedra's elimination, not control. Unless total removal is your goal (I am asuming you want it around in your garden, just not climbing on everything!), be careful using the chemicals they suggest.   

It's nick-name is the "cockroach plant" because of its vigor in refusing to die - we like that here in the hot, dry west!  We can barely keep it alive, whereas the rest of the U.S. can't seem to kill it!

Good luck!