Division 21 / Estimated
Division 21 fire sprinkler estimating
On sprinklers the head count is decided before the drawing is read, by the hazard classification. Miss that and every quantity after it is wrong in the same direction.
What we measure, and in what units
- EA heads by type, finish and temperature
- LF pipe by size
- EA fittings, valves and devices
- EA risers and standpipes
- SF coverage by hazard classification
What the deliverable looks like for this division
Coverage area by hazard classification, then head spacing and density from that, then the head count checked against the ceiling plan where head locations actually get decided. Pipe by size along the routed mains and branches, risers and standpipes by count.
Scope items routinely missed on this division
Only someone who has priced the work knows what falls through the gaps. No competitor publishes this list.
- Hazard classification driving head spacing and density, which changes the count before anything is measured.
- Head type and finish, since concealed, sidewall and upright are not interchangeable in price.
- Escutcheons and trim, counted with the heads.
- Seismic bracing on mains and branches.
- Hydraulic calculations and the engineering that goes with them.
- A fire pump where the supply requires it.
- Backflow prevention at the service entry.
- Coordination with the ceiling grid layout, which is where head locations actually get decided.
- Sleeves and firestopping at every penetration.
Documents needed to price it
- Fire protection drawings
- Hydraulic calculations
- The hazard classification
- Reflected ceiling plans
- The specification
Questions people in this trade actually ask
How is the head count derived from the hazard classification?
The classification sets the design density and the maximum coverage per head, which sets the spacing. Coverage area divided by that spacing gives the count, which is then checked against the ceiling plan where obstructions and grid modules move heads.
Are hydraulic calculations included?
They are identified as a scope and priced as one where the specification puts them on the contractor. They are engineering, and they are stated as such rather than absorbed.
How does ceiling coordination affect the number?
Heads move to grid centres, avoid lights and diffusers, and pick up extra drops at soffits. The count from spacing alone is a floor, and the ceiling plan is what turns it into a real number.
The service behind this
Estimating & TakeoffRelated divisions
Bidding Division 21 work?
Send the documents and the bid date. A written fee and turnaround come back before anything is measured.