Designing Kitchens and Bathrooms - Mold Everywhere, Please Help!!!

I own a log home, my downstairs bathroom ceiling has 12 x12 beams running thru it, also the ceiling is the upstairs floor, so there is a lot of wood exposed. When new the would was treated with a semi gloss Polyuretane.

My problem is everything is covered in black mold, I have tried everything, from Bleach to commercial cleaners, nothing seems to remove it. my next idea was to wire wheel the wood, if that don`t work, it was suggested to me to have the room sandblasted, that seems a little drastic, but at this point I am ready to try anything, I am embarrassed to the point I make guests use the upstairs B-room.

Please help, any suggestions would be greatly appreciated.

I f bleach doesn't work, you have a real problem. But maybe the solution is too strong. Try a 10-25% mix with water. if no luck..........you have a real problem, call the pro's.