Mold can be killed. Prior to sealing the bemas bring in an Ozone Generator (professional unit)and run it in the home with the windows and doors closed. Leave no plants, animals or humans in the building until you are done (Ozone is a lung irridant and reduces CO2). A large machine can do a home in 24 hours easliy. It also remove the mold in walls as well. Mold can grow back on the bleach once the clorene has dissapated. Plus you run the risk of damaging the beams. It is very very dangerious to spray straight bleach on surfaces like open beams that may have amonia's in them.