More Detail: Life Safety Systems

Life Safety Systems for Existing Mid-Rise Office Buildings in North Texas

Life safety systems—primarily fire alarm and fire sprinkler systems—are among the most regulated construction elements in any mid-rise office building. In North Texas, where mid-rise commercial properties range from 4 to 12 stories and may be decades old, life safety work often requires navigating legacy infrastructure, differing code eras, and jurisdictional nuances. TI projects, building reconfigurations, capital upgrades, and system repairs all trigger life safety modifications. This page details each major system type, its components, and considerations specific to the North Texas commercial environment.

1. FIRE SPRINKLER SYSTEMS

Almost all mid-rise office buildings in North Texas are fully sprinklered, typically with wet-pipe systems, though certain areas (parking garages, equipment rooms) may include dry or pre-action systems.

A. Wet-Pipe Sprinkler Systems

The dominant system type for administrative and commercial office spaces.

Key Components:

• Riser assemblies (usually located in fire riser rooms on each floor or in stairwells)
• Black steel piping (schedule 10 or 40 depending on era)
• Sprinkler heads (pendent, upright, concealed, sidewall)
• Inspector’s test valves
• Pressure gauges, flow switches, and tamper switches
• Alarm check valves

North Texas Considerations:

• Heat exposure in unconditioned areas can cause premature wear on gaskets and valves.
• Hard water mineral content in many municipalities leads to internal pipe scaling in older systems.
• Tenant improvements frequently require head relocations due to wall changes, ceiling changes, or decorative elements.

B. Dry-Pipe Systems

Used in non-conditioned spaces such as exterior balconies, parking structures, or certain attic spaces.

Key Characteristics:

• Pipes are filled with compressed air or nitrogen until activated by heat.
• Valve rooms require heat trace or insulation to prevent freeze damage.

Challenges in North Texas:

• Sudden winter freeze events can burst pipes if maintenance lapses.
• High temperature swings affect dry system sensitivity and reliability.

C. Pre-Action Systems

Occasionally found in server rooms, telecom rooms, or specialty areas.

Types:

1. Single interlock
2. Double interlock

Purpose:

Prevents accidental discharge by requiring detection (heat or smoke) before water enters the pipes.

D. Sprinkler Head Types & Applications

Sprinkler heads vary based on room type, fire hazard classification, and aesthetic requirements.

Common Types in Mid-Rise Offices:

• Standard Pendent: Used in most dropped ceilings.
• Concealed Heads: Used in Class A office finishes and lobbies.
• Sidewall Heads: Used in corridors and perimeter zones.
• Upright Heads: Used above open ceilings or mechanical rooms.

Texas-Specific Concern:

UV exposure near exterior glazing can degrade certain head finishes over decades. E. TI Impacts on Sprinklers

Tenant improvements require:

• Re-calculations of sprinkler coverage
• Re-routing branch lines
• Replacing heads to match new ceilings
• Upgrading heads to quick-response types
• Ensuring spacing meets NFPA and local fire marshal requirements

City of Dallas, Plano, Frisco, and Addison fire marshals each have unique preferences for inspection sequencing and permitting timelines.

2. FIRE ALARM SYSTEMS

Fire alarm systems provide detection, notification, and communication for building occupants and responding agencies.

A. Fire Alarm Control Panels (FACP)

Older mid-rise buildings often operate with legacy panels that may not integrate easily with newer devices.

Modernization May Include:

• Upgrading the main FACP
• Replacing annunciator panels in building lobbies
• Migrating from conventional to addressable systems

Local Requirement:

Cities like Dallas mandate UL-listed monitoring companies and require tamper and flow devices to activate supervisory alarms.

B. Detection Devices

Smoke Detectors:

• Photoelectric detectors for hallways, electrical rooms, and mechanical rooms
• Duct-mounted smoke detectors for AHUs and RTUs

Heat Detectors:

• Used in kitchens, mechanical rooms, and elevator shafts

In older North Texas buildings, detector spacing must often be corrected to meet modern NFPA 72 requirements.

C. Notification Appliances

Mid-rise offices require both audible and visual notification:

Horn/Strobe Combinations:

The most common devices in tenant spaces, hallways, and lobbies.

Speaker/Strobe Systems:

Used in higher-end or more recently built mid-rise buildings.

Provide voice evacuation messages, often required in multi-tenant mid-rise structures.

Strobe-Only Devices:

Used in restrooms, breakrooms, and enclosed private spaces.

ADA Considerations:

Strobes must meet candela requirements for room size and configuration.

D. Pull Stations

Required at exits, stairwells, and certain egress points. Many older buildings have outdated pull stations that must be replaced during major upgrades.

E. Fire Alarm Integrations

Modern systems integrate with:

• HVAC shutdowns
• Smoke evacuation systems
• Elevator recall operations
• Magnetic door hold-opens
• Fire pumps

Elevator recall is particularly important as many older buildings must upgrade controllers or door hardware to comply.

3. FIRE PUMPS

Not all mid-rise office buildings require fire pumps, but many built after 1980 do.

Types:

• Electric fire pumps
• Diesel fire pumps

Components:

• Jockey pump (maintains pressure)
• Pressure relief valves
• Flow test header

Fire pumps require annual flow testing, often coordinated during TI projects.

4. SMOKE CONTROL SYSTEMS

Certain mid-rise buildings with specific design features (atriums, large lobby openings, interconnected floors) require smoke control systems.

Elements May Include:

• Stairwell pressurization fans
• Elevator hoistway smoke relief
• Smoke dampers
• Mechanical exhaust systems
• Relays tied to fire alarm panels

TI work must not compromise smoke-control zones or fire-rated assembly penetrations.

5. FIRE-RATED ASSEMBLIES & LIFE SAFETY CONSTRUCTION

Beyond fire alarms and sprinklers, life safety includes ensuring that all fire-rated components remain intact and compliant.

A. Fire-Rated Walls & Partitions

Common rated walls in mid-rise buildings:

• Stair enclosures (2-hour)
• Elevator machine rooms (1–2 hour)
• Mechanical/electrical rooms (1-hour)
• Corridor walls (1-hour in many jurisdictions)

TI work often requires verifying missing fire caulk or correcting penetrations from past contractors.

B. Firestopping

Penetrations through rated walls or floors must be sealed with UL-listed assemblies.

Typical penetrations requiring firestopping:

• Conduits
• Sprinkler penetrations
• Cable trays
• Plumbing lines
• HVAC ducting with fire dampers

North Texas inspectors are particularly strict about proper fire damper installation and inspection port visibility.

C. Egress Requirements

TI modifications often trigger changes to:

• Exit signage
• Egress lighting
• Corridor widths
• Door hardware
• Clearances at reconfigured rooms

Cities like Frisco and Plano have stringent exit illumination requirements tied to emergency lighting.

6. CONSTRUCTION IN OCCUPIED BUILDINGS

Life safety work frequently requires:

• After-hours fire alarm shutdowns
• Fire-watch personnel during system impairments
• Coordinated tests with the local fire marshal
• Clear tenant notifications when devices will be tested

False alarms can create major operational disruptions, so TI contractors must protect devices during work.

7. TESTING, INSPECTION & COMMISSIONING

Common inspections in North Texas:

• Rough sprinkler piping inspection
• Hydrostatic testing for new piping
• Valve and flow switch testing
• Fire alarm pre-test (contractor test)
• AHJ acceptance test with fire marshal present

Buildings in Dallas, Plano, and Irving each have unique inspection sequences.