I have removed the shutters from the second floor windows. Behind one of them were approximately twenty bats. I have hosed off the area, scraped off any residue, washed with a strong mixture of bleach and water, and I'm now planning to undercoat with Kilz. This paint product is supposed to control mold and mildew.
Before I apply this product what is your advice? I read your article regarding getting rid of the odor with "Rough 'n Ready", although I'm wondering if the bleach mixture will do it.
Once the area behind the shutter is "clean" and free from odor, is there any product that I could apply behind the shutter before I put it back on the house. (Someone told me that I could tack up a layer of aluminum foil behind the shutter, but I'm not sure if that is a viable solution.) Please reply at your earliest opportunity.
Bat urine and feces can fester quite an odor. There are all kinds of enzymes and other bioagents at work in their excrement and though bleach will help reduce these components, I'm not sure it will do the job to your level of satisfaction. If you find the odor is still active after a couple of days (especially in the warmth of the summer), get the ROUGH'N READY and apply it liberally to the area. It will penetrate where all these living organisms are residing and should neutralize them completely compared to just bleach.
Additionally, inspect the area directly underneath the shutters. If the droppings were falling onto some part of the home, it may need to be cleaned too and Bleach may not be an option in this area. Rough'n Ready can be used pretty much anywhere without concern.
As for what you "could apply behind the shutter"; I'm guessing you are asking what type of bat repellent would be good to use there so they don't come back, correct? If so, I would say the 4-THE-BIRDS GEL or LIQUID REPELLENT would be ideal and would insure they would be gone for good. We have other products listed in our BAT CONTROL ARTICLE, but either one of these should do the job nicely.