FireproofingRenovation · Planning guide
Planning service penetrations in a mass-timber building
Do not carry a concrete-wall assumption into a different construction system.
This guide helps you prepare a professional conversation. It does not specify a rated system, product thickness or installation method.
The substrate is part of the question
UL Solutions’ research on cross-laminated timber and firestop systems reports that timber characteristics can influence system performance. It points users toward certified systems for the relevant CLT construction. That does not mean one research result or one listed detail establishes suitability for every mass-timber building.
Bring the structural and services teams together
At concept stage, ask where services will cross the proposed rated construction and who coordinates those locations. Share the actual timber system information, architectural drawings and intended service types with the qualified reviewers. Keep connection details and other structural decisions with the structural engineer. Owners can help by identifying late tenant requirements early rather than allowing unplanned openings to become a site problem.
Request a location-based closeout
Ask the project team to document the accepted protection approach and its supporting references for each condition. Record how changes to service routes or timber construction will be reviewed. Include inspection and handover expectations in the contract, and keep the approved record available for future fit-outs. This guide offers coordination questions only. It does not authorize drilling, cutting, material substitution or any specific firestop arrangement in timber construction.
Protect the information through tenant changes
A future tenant may see only a convenient wall or floor location for an additional service. Give the facilities team a route for checking the existing project record before approving alterations. Ask designers to provide information in a form the operating team can find, and explain who must review a proposed change. A short tenant-work briefing can point to that process without exposing sensitive drawings publicly. Keep any new accepted details linked to the affected location so the next project does not start from an incomplete set of assumptions about the construction.
Primary sources & further reading
Published November 11, 2026 · Fireproofing.tv editorial desk