Wet-Pipe Sprinkler Winter Readiness Checklist: 7 Things to Verify Before the First Freeze

A wet-pipe sprinkler system depends on water remaining available in its piping. When cold reaches a vulnerable area, frozen water can damage pipe and fittings. Leaks may not become apparent until temperatures rise and the ice begins to thaw.

Building owners and facility managers can use this checklist to identify winter risks before the first freeze. It is a companion to our full seven-step guide to wet-pipe sprinkler winter readiness, which provides additional preparation guidance.

This checklist is not a substitute for an inspection or for the requirements that apply to your building. Have a qualified fire protection professional assess deficiencies and perform system work.

1. Identify every area where sprinkler piping may be exposed to cold

Start with the piping, not just the building thermostat. Wet-pipe sprinklers may extend into spaces that are colder than regularly occupied areas or that lose heat quickly.

Check building plans and walk the facility to identify piping in or near:

• Attics, roof spaces, and unheated mezzanines

• Exterior walls and concealed spaces

• Loading docks, vestibules, stair towers, and penthouses

• Valve rooms and other spaces with exterior exposure

• Areas affected by open doors, broken windows, or ventilation openings

Pay particular attention to spaces that are normally unoccupied. A room can be warm during a routine daytime walkthrough and still become cold during an overnight heating failure or extended period of severe weather.

2. Confirm vulnerable spaces can maintain adequate heat

Verify that heating equipment serving areas with wet sprinkler piping is operating and that the heat reaches the areas where the piping is located. A thermostat reading in an office or main work area does not confirm the temperature in an attic, loading area, or valve room.

Public fire-safety guidance commonly recommends maintaining at least 40°F (4°C) in spaces containing wet-pipe sprinkler piping. Requirements and system conditions can vary, so confirm the appropriate conditions for your building with a qualified fire protection professional and the authority having jurisdiction (AHJ). The Fairfax County Fire Marshal’s sprinkler winterization guidance provides additional cold-weather guidance for building owners.

Consider how the space will be monitored during nights, weekends, holidays, and heating-system outages. If a low-temperature alarm is installed, confirm it is operational and that alarm signals will be received by the responsible staff or monitoring provider.

3. Inspect doors, windows, insulation, and other sources of cold air

Look for conditions that allow cold air to reach the piping or reduce the effectiveness of building heat. Check exterior doors and windows, roof openings, louvers, vents, and loading-area doors. Ensure that doors and vents are used and maintained as intended, and that damaged openings are repaired.

Inspect insulation near sprinkler piping for gaps, displacement, moisture damage, or deterioration. Do not cover sprinkler heads, valves, or other components with insulation or materials that may obstruct access or affect operation. If you are unsure whether insulation work could affect the sprinkler system, consult a fire protection professional before proceeding.

4. Have heat tracing inspected where it protects wet piping

Heat tracing may be part of an approved freeze-protection arrangement for specific piping. If your facility relies on it, ask a qualified professional to verify that the installed system is suitable for the application and is operating as intended.

The review should include the heat-trace equipment, its power supply, controls, visible condition, and associated insulation. Follow the manufacturer’s instructions and applicable design requirements. Do not assume that a cable is working because it is present, or modify or repair heat tracing without qualified assistance.

A loss of power, damaged cable, failed control, or disturbed insulation may leave piping vulnerable even when the surrounding room appears warm.

5. Have antifreeze protection verified by a qualified professional

Some sprinkler systems use antifreeze in sections that cannot be reliably protected from freezing by building heat alone. The solution type, concentration, system design, and product listing matter. Do not add automotive antifreeze or another product, dilute the solution, or attempt to adjust its concentration.

Before cold weather, have a qualified fire protection professional verify that the system’s antifreeze arrangement is appropriate for the installation and expected conditions. Testing and any corrective work should follow the applicable requirements, product instructions, and AHJ direction. The NFPA’s winter sprinkler guidance discusses steps building owners can take to prepare sprinkler systems for cold weather.

6. Confirm valves, alarms, and system conditions are being monitored

A winter walkthrough is a good opportunity to confirm that the sprinkler system remains in its normal operating condition. Do not operate valves or make adjustments unless you are authorized and qualified to do so.

Review the facility’s established procedures for checking:

• Whether control valves are in their required normal position and secured as designed

• Whether supervisory or low-temperature alarm conditions are present

• Whether water supply and system pressure indications are within their expected range

• Whether leaks, corrosion, physical damage, or other visible changes need professional attention

If a reading appears abnormal or an alarm activates, promptly notify the responsible building staff and your fire protection service provider. Do not silence or bypass a supervisory signal without following the applicable procedure.

7. Document your checks and know what to do if the system is impaired

Keep a record of the areas reviewed, temperature concerns, alarm conditions, visible deficiencies, notifications, and corrective actions. Documentation helps facility teams track recurring cold spots and share relevant information with service providers.

Before winter, confirm who is responsible for responding to a heating failure, low-temperature alarm, suspected frozen pipe, or sprinkler leak. If the sprinkler system must be shut down, drained, repaired, or otherwise taken out of service, follow a formal impairment procedure. Coordinate required notifications and safeguards with the appropriate parties, which may include the AHJ, alarm-monitoring provider, insurer, occupants, and a qualified fire protection professional.

Do not attempt to thaw a sprinkler pipe with an open flame, or patch, drain, refill, or modify the system yourself. A suspected freeze or damaged pipe requires prompt professional assessment. A fire protection professional can determine the condition of the affected piping, make repairs, and advise on restoring service safely. Safeway Fire Protection also provides service for fire sprinkler systems, including repair of busted pipes.

A practical pre-freeze review

Before temperatures fall, building owners and facility managers should be able to answer these questions:

• Have we identified all areas containing cold-exposed wet sprinkler piping?

• Can those areas maintain the appropriate temperature through nights and heating interruptions?

• Are doors, windows, insulation, and heat-trace systems in suitable condition?

• Has a qualified professional verified any antifreeze protection?

• Do staff know how to report alarms, suspected freezing, and system impairments?

• Are checks, deficiencies, and completed repairs documented?

A winter readiness review can help identify vulnerabilities before they become leaks or system outages. Safeway Fire Protection provides a single-source approach to fire sprinkler system design, installation, inspection, maintenance, and repair. For building owners and facility managers, proactive professional service supports risk mitigation, system reliability, and confidence that critical fire protection remains ready through the winter season.