Despite popular belief, spraying bleach doesn't kill mold and can actually make it worse. While bleach kills the surface mold, the water in it will feed the roots and guarantee it comes back. All you've really done is disturb the surface. Once mold is in/on a porous surface like wood, it usually needs encapsulated or replaced. You could try an ozone generator but it's no guarantee and they have their risks as well. Mold remediation is an expensive affair requiring HEPA scrubbers and usually replacing the affected materials.