Prepare a written fire prevention plan and a moisture management plan, put their requirements into the drawings and specifications, and share them with the broker and insurers before the policy is bound. The Mass Timber Insurance Playbook calls this engaging insurers early, and it treats design, fire, and water management as one risk story.
Why construction is the risky period
A finished mass timber building has its protection, detection, and sprinklers working. During construction, much of that is not yet installed, and the exposed timber can get wet. The Mass Timber Insurance Playbook (Alliance for Sustainable Building Products, May 2023) notes that the risks are different before fire-resisting surfaces have been installed, and it lists “Engage Insurers Early” among its essential principles. WoodWorks published a U.S. edition of the playbook with insurance and resilience experts. The playbook is deliberately non-prescriptive and does not guarantee insurability.
The UK edition references UK regulations and codes of practice. On a U.S. project, the adopted fire code and NFPA 241 govern safeguards during construction, and the authority having jurisdiction decides what applies. Sources verified October 22, 2026.
What to prepare and where it belongs
| Topic | What to prepare | Where it should appear |
|---|---|---|
| Insurer engagement | Bring the broker and insurers in before the policy is bound. Share the design, loss control plans, and quality control plans. | Project schedule, risk register, broker submission |
| Fire prevention | A site fire prevention plan covering hot work, combustible storage, waste, security, and fire department access. The WoodWorks BC checklist asks for a fire-safety plan when welding near mass timber. | Contractor plan, specifications, site logistics plan |
| Temporary protection | Temporary measures that limit fire spread and water damage while permanent protection is incomplete, such as protecting exposed timber and sequencing protection behind erection. | Specifications, phasing drawings, moisture plan |
| Moisture management | A written moisture management plan. WoodWorks says specifications commonly require the contractor to write it and submit it for approval. | Specifications, submittals, enclosure details |
| Moisture limits | A maximum timber moisture content before toppings, acoustic mats, or low-permeance layers cover the panels. WoodWorks gives 16% as an example. | Specifications, floor assembly details |
| Records | A dated record of what was installed, including photos of fire stopping and cavity barriers before they are covered, as the playbook recommends. | Quality control plan, closeout requirements |
| Repair and tolerances | Agree with insurers how damage will be assessed and repaired, and which tolerances matter, such as structural integrity versus appearance. | Insurance discussions, specifications for exposed timber |
Make the plans visible in the documents
A plan that exists only in a contractor’s binder is hard for an insurer to rely on. Check that the specifications require each plan, name who prepares and approves it, and describe what happens when timber gets wet. The Mass Timber Construction Success Checklist from WoodWorks BC and Seagate Mass Timber asks whether the moisture plan was prepared with input from the mass timber supplier, covers mitigation after significant wetting, and divides scope clearly between the installer, supplier, and general contractor.
Then compare the documents with each other. A floor assembly detail that shows a concrete topping should agree with the moisture limit in the specifications. WoodWorks advises against installing a concrete topping before the mass timber assembly is shielded by watertight walls or construction barriers, so the phasing drawings and the topping specification should tell the same story.
Questions to settle before the policy is bound
- Who is the broker, and have the insurers seen the design and the construction-phase plans?
- Which plan covers fire prevention, and who enforces it on site every day?
- Which plan covers moisture, who approved it, and does it include the supplier’s input?
- What moisture content must the timber reach before it is covered, and how will it be measured and recorded?
- How will damaged timber be assessed and repaired, and what are the lead times to remanufacture a panel?
- What record of hidden work, such as fire stopping, will exist when the building is handed over?
Where Groundbook fits
Upload the drawings, specifications, and the plans you rely on as references, and run a drawings and specifications review. Groundbook flags potential disagreements, such as a topping detail that conflicts with the specified moisture limit, with links to each source. It does not assess insurability, write the fire prevention or moisture plans, or replace your broker, insurer, or authority having jurisdiction.