The floor under the upstairs shower had significantly deteriorated due to a water leak, compromising its structural integrity. The leak affected the main bathroom, WC, and ensuite. A full-height strip of these areas was removed to address microbial growth. Upon removal, the floor was found to be unsalvageable. The yellowtongue was trapped beneath the floor joists and base plates in an unusual construction, requiring remediation and removal. After the floor was taken out, we returned to perform antimicrobial remediation on the remaining floor and exposed joists and wall studs. We used Surface Shield, an encapsulant suitable for situations where timbers cannot be practically removed. This product allows water to escape while containing microbial contamination. All affected areas were treated, and a PRV was conducted through swab and air sampling by an occupational hygienist, which passed.