Yes cats will pee everywhere when coming into heat, and sometimes in-between heats. Its their form of marking the territory and attracting males. Spaying should definitely fix the problem.
Edit: I just looked at your site and you breed bengals? In that case, understand that females can be worse than males when it comes to spraying and peeing when in heat. They need facilities where you can keep them that are easily cleanable while they are in season. Also get Poise pads (the kind that are mats, not like the ones for periods) for people with urinary trouble. They are pads you place where you want to sit down and have a plastic underside so no mess is made. I use these in the favorite places in the house that Meeka likes to go.