We just bought a house with a leaky fireplace. The flashing on the roof has lost it's seal. From the water that has leaked through and into and around the upstairs fireplace for who knows how long I have a strong sour moldy smell all around my fireplace. I have ripped out all the moldy drywall that was in the downstairs ceiling around and under the fireplace but it stillll stinks bad. How do I kill all the mold I assume is growing like mad down the inside of the Upstairs fireplace? Pour bleach water into the loose flashing on the roof and let it trickle down behind the fireplace and walls and hope it kills it all then reseal the flashing or just fix the flashing and hope over time the mold will dry up and go away, or some other solution other than tearing down the whole fireplace.??