Dry rot remediation across a full bedroom floor of an operating hotel

Dry rot was found in the cross-laminated timber (CLT) structure beneath guest bedrooms. We used targeted investigative openings to establish the true extent, then remediated room by room while the rest of the hotel continued trading.

Client and location details are withheld at the client’s request.

What we found

We were first instructed to investigate flooring movement and suspected microbial damage in a recently built hotel. Moisture and mould surveys flagged affected bedrooms, and invasive investigation in two out-of-order rooms confirmed dry rot in the building’s cross-laminated timber (CLT) structure.

The decay was concentrated in the CLT subfloor, the external wall panels beneath the windows, and the panels beside each bathroom pod. Where panels were opened, decay typically extended beyond 50mm into the timber, well past the 20mm maximum depth that can be repaired in place.

Typical bedroom, schematic and not to scale. Zones A and B are the 1300mm strips of floor opened in every room to expose the wall panels where decay was expected. Sound centre floor sections were treated and left in place rather than removed by default.

How the works were delivered

Assess. A moisture and mould survey across the floor, with rooms flagged by risk and two out-of-order rooms opened up first.
Verify. Openings confirmed decay beyond repairable depth, so the scope was revised to open two targeted zones in every room before deciding what to remove.
Remediate. Contained, negative-pressure work areas; affected CLT removed or treated; OXID-8/B-RINSE decontamination and SteraMist treatment; drying where needed.
Clear. ATP surface testing and air sampling with laboratory analysis. No room was signed off until results were acceptable.

Keeping the hotel trading

The affected floor was taken out of use so works could proceed without guests present, while the rest of the hotel stayed open. Power tools were restricted to 10:00–17:00, doors and windows were kept closed, and no equipment ran outside the building. Strip-out and waste were handled by the principal contractor, with our team leading decontamination and treatment and reporting progress daily.