NOVA Fires in Single Family Dwellings Manual

• The Single-Family Dwellings Manual, Fourth Edition was developed through a cooperative effort of Northern Virginia fire departments.
• The first edition released in 2002, the second and third editions were revised in 2008 and 2013.
• Thousands of U.S. civilians are injured or killed each year by fires in single-family dwellings.
• Lightweight construction materials and techniques have increased the potential for early collapse in these buildings, increasing the life safety hazards.
• A size-up that includes viewing as many sides of the structure as possible is required due to the variety of layouts and floor plans found in single-family dwellings.
• Key changes to the fourth edition of the NOVA Fires in Single Family Dwellings manual include:
  • Significant content reorganization to improve document structure.
  • Inclusion of content related to solar panel installation on residential roofs.
  • Inclusion of content related to wind-driven fires.
  • Expanded content related to attic fires.
• The manual describes construction features of single-family dwellings found throughout Northern Virginia, inherent firefighting problems, operational priorities, and known risks and hazards.
• The manual also establishes a standard operation method for fighting fires in these types of structures.

Description

• Single-family dwelling (SFD) describes a residential building occupied by one household or family, with allowances for basement or in-law suites.
• Accommodations like duplexes, townhouses, short-term rentals, and large-scale rentals are excluded.
• SFDs typically have a yard and are in housing developments with similar dwellings, or they may be situated alone in a rural setting.

General Characteristics

• SFDs can range from one to three floors and vary in height from front to rear.
• They can rest on a basement, crawlspace, or slab, and may or may not have a garage for one to four vehicles.
• Garages can be on the lowest level in the front, side, or rear, or be detached.
• Most SFDs are rectangular with four sides, two parallel load-bearing exterior walls, and one interior load-bearing wall located centrally between the exterior walls.
• SFDs often include water, sewer, gas, electric, and communications systems.
• Larger structures may have commercial utility installations or multiple installations of the same utility.
• Unfinished basements can lead to quick fire spread and structural compromise.
• Fire department access and interior living space can vary.
• The degree of compartmentation created by the number of separated rooms makes the individual compartments relatively small.
• Renovations to accommodate multifamily use can result in unexpected compartmentation and layouts.

Construction Styles

• Common SFD styles in the Northern Virginia region include:
  • Colonial.
  • Rambler or ranch.
  • Cape Cod.
  • Split foyer.
  • Split level.
  • Balloon frame.
  • Hybrid.
  • Estate homes or McMansions.
  • Cluster homes.

Colonial Style

• A colonial style home usually has two stories above ground and may or may not have a basement.
• The front door leads into the structure's main entryway and stairwell.
• Living and dining areas are usually located on the first level, with bedrooms on the second floor.

Ranch or Rambler

• These homes are usually one story and may or may not have a basement.
• The floor plan is typically very open, and large windows are common.
• A distinctive feature is the presence of large extended eaves.

Cape Cod

• Cape-Cod-style homes are typically 1 ½ stories above ground.
• The front door provides access to the main stairwell leading to the upper bedrooms and basement, if present.
• The top floor will contain knee walls and may contain dormers.

Split Foyer

• This is a two-story SFD with an interior foyer level leading to stairs for both upper and lower levels behind the front door.
• Although split foyer SFDs typically stand no taller than two stories, three- and four-story spilt-foyer SFDs can be found in the region.
• Split-foyer SFDs can be identified by comparing the relative height of the windows and the front door on side Alpha, as the top of the windows and the top of the door will be offset.
• Living quarters in split-foyer homes may occur on the basement level.

Split Level

• A split-level home is a three-level SFD with a front entry to an interior level between upper and lower floors, with two short sets of stairs providing access from the main entry level to levels above and below.
• Split level style homes typically incorporate three-level designs, however four- and even five-level spilt-level SFDs can be found in the region.
• Bedrooms are typically located on the second floor in these dwellings.

Hybrid

• Hybrid-style SFDs are an increasingly popular new genre and can involve variations of several different styles.
• They are typically wood frame and provide two separate occupancies separated by a fire wall in a one-story portion of the structure (storage shed, garage, or breezeway).

Estate Homes and McMansions

• The terms estate home and McMansion are often used interchangeably to describe large SFDs.
• Regardless of their geographic location, these homes share common characteristics that affect fire ground operations.
• They are typically wood frame with a large amount of open space in the attic area and may have heating, ventilation, and air conditioning (HVAC) components in the attic area to facilitate multiple zones.
• The presence of an HVAC system in the attic creates a dead load that could adversely affect the companies operating below if fire involves this area.
• The interior layout resembles Colonial-style homes but on a significantly larger scale that usually includes a large open foyer in the home's entranceway.
• HVAC units, large light fixtures, dormers, and gables create extra loads that pose a collapse hazard when fire enters the area above the open foyer.
• The first floor typically consists of living and dining areas, with bedrooms located on the upper floors.
• Most rooms have large, vaulted ceilings that facilitate fire travel.
• Note that these houses may have more than one kitchen and newer homes may have one kitchen on the main level and a second one in a basement in-law suite.

Cluster Homes

• These reside in a community of single-family detached homes built in very close proximity to each other and are usually constructed of lightweight building materials using the frame method.
• They typically have vinyl or wood siding, zero clearance chimneys, and narrow travel lanes separating each structure.
• Cluster home developments lack firewalls, creating a high potential for lateral fire spread and fire extension to exposures in adjacent structures is a major concern due to their proximity.
• These homes often are spacious with well-designed, open floor plans that can facilitate rapid fire spread throughout the structure.
• These homes are typically one to three stories in height with windows facing the exposures, leading to rapid horizontal fire spread.

Construction

• SFD design typically involves wood-framed materials and a platform-frame construction method which limits vertical fire extension in the walls.
• Wood-framed SFDs built prior to the 1930s may have utilized balloon-framed construction methods with long, continuous studs that run from the basement to the attic.
• The absence of fire stops between floors leads to rapid fire spread.

Roofs

• SFD roofs are typically constructed utilizing lightweight or wood frame methods.
  • Lightweight roofs utilize triangular trusses or parallel chord trusses or plywood I-beams that rest on load-bearing and non-load-bearing walls on the top floor that from the front and rear load-bearing walls to a ridge pole.
  • Wood frame roofs rely on sawn wood rafters that form the roof peak from the front and rear load-bearing walls to a ridgepole.
• SFD roof decking is typically constructed with 4' by 8' plywood sheathing or particleboard.
• Flat roofs may utilize gypsum board integrated with fiberglass for decking (Securock or DensDeck).
• Roof decking applied over sawn wood rafters is typically plywood sheathing, although occasionally, 1" by 4" or 1" by 6" boards are found nailed perpendicular to the rafters.
• Roof coverings typically involve asphalt shingles; however, slate and wood shingles are not uncommon.
• Many SFDs constructed during the 1980s have fire retardant (FR) plywood sheathing roof deck, however, over time, early decomposition showed much of this FR plywood to be defective.
• Personnel should question the integrity of an FR plywood roof, even before a fire occurs.
• Personnel may encounter flat and mansard-style roofs.
• Firefighters should remain cognizant of the knee walls created by mansard-style roof construction and the inherent potential for fire spread in these void spaces.
• Roof coverings will generally be shingle over felt or synthetic paper, or a variation thereof, however, the vast majority will be either asphalt shingles or cedar shakes.
• Solar panels additional weight that might cause collapse, presence of stored energy, and limiting areas in which to perform vertical ventilation.

Attics

• Attics, if present, are usually unfinished, and occupants may use them for storage, accessed through a scuttle or pull-down staircase in the top-floor ceiling.
• Attic space can also house water heaters and HVAC units, and in some cases, can serve as living space.
• The insulation material used within attics is generally fiberglass, wood cellulose, rigid plastic foam, or other blown-in material.
• In lieu of an attic, SFDs may have a top-floor vaulted ceiling or loft.
• The attic may include flooring that makes it difficult to apply fire streams from the floor below.

Walls

• Walls are constructed of 2" by 4" lumber and may be load-bearing or non-load-bearing.
• Lightweight aluminum studs occasionally appear in non-load-bearing walls.
• Most walls in SFDs have either 16- or 24-in. on center studs.
• Knee walls can occur in SFDs with lofts and dormers, sometimes are used by building occupants for storage.
• Exterior walls may be covered with brick veneer, wood, aluminum, or vinyl siding over a thin layer of insulating sheathing.
• Foundation walls are constructed using either masonry block or a poured reinforced concrete monolithic (i.e., cast-in-place) wall.

Insulation

• Insulation can be rolled fiberglass, blown-in rock wool, blown-in cellulose, or spray foam.
• Insulation occurs in attics, exterior walls, and in some structures, the interior walls.

Floors

• Floor decking is usually comprised of ½- or -in. thick wood boards or wood composite sheets (i.e., plywood or oriented strand board).
• The decking may be covered with carpet and pad, masonry or vinyl tile, or wood.
• Decking material is laid on sawn wood joists, parallel chord trusses, or plywood I-beams.
• These joists, trusses, or beams are spaced from 16 to 24 in. apart on center and run side-to-side or front-to-rear.
• Basement load-bearing walls typically support side-to-side floor joists and if these construction features exist in an unfinished SFD basement, they present a collapse hazard when exposed to fire.
• Engineered I-beams exposed to fire can fail within 5 min.

Windows

• The double-hung, sliding sash window represents the most common style of window used in present-day SFDs.
• The glazing may be of single, double, or triple thickness.
• Casement windows have steel frames set in concrete or masonry which creates a special hazard.
• Security bars present a specific hazard to both trapped occupants and operating firefighters.

Doors

• Interior doors are commonly constructed of hollow-core wood, with inward openings leading to bedrooms and bathrooms and outward openings leading to basement stairs or closets.
• Different door orientations occur in the region's varying construction styles.
• Exterior doors on SFDs may be solid wood, composite, insulated metal, or wood panel.
• Sliding glass or French doors may exist on the building's rear and swing inward.
• Standard locks on exterior doors are mortise, rim, and tubular dead bolt.

Stairs

• Multilevel SFDs commonly incorporate a stairway, either open from the lowest living level to the highest, or a straight run, vertically stacked stairway, and larger homes may have multiple stairways, some of which may be remote from the front entrance.
• Steep, narrow, or spiral stairways can hinder hoseline advancement and rescue operations and stairs require hoseline protection to maintain access and egress routes.
• Stairs are stacked in most cases and basement stairs can be unfinished on the underside, with storage is common beneath them.

Garages

• Municipal fire codes require garages attached to living spaces must have fire-rated interior walls, doors, doorframes, and hardware.
• Although surrounded by fire-rated materials, a vehicle, or other contents, fire can rapidly extend to other areas in an SFD.
• Overhead entrance doors and their associated mounting hardware must be fire-rated and personnel should secure the opened garage door.

Chimneys

• They can be either masonry with a tile flue or wood-framed with a metal flue.
• The metal flue, also known as a zero clearance or prefabricated chimney, wood- framed chimneys can lack fire-stopping and can interconnect to adjoining floor or ceiling voids.

Basements

• SFDs will rest on a concrete slab or will have a crawl space or full basement underneath, or they will have a combination of both.
• Basement entry may involve an exterior or interior stairway, or both.
• Crawlspace and basement walls are generally built of block or poured concrete.
• Unfinished basements allow the fire to directly attack the building's structural components and quickly enter void spaces.
• Sleeping quarters in SFD basements should include egress windows and window wells, illegal sleeping quarters may be created.

Hazards

• This describes hazards that may occur in SFDs.

Life Hazards

• Most fire-related fatalities in the United States occur in SFDs.
• Positive pressure from a fire can cause smoke to migrate into adjacent areas through open stairways and common voids.
• Subleasing may create an additional life hazard as both basement and sub-basement areas may serve as sleeping areas with separate locked entrances.
• SFDs can be used for other purposes besides residential housing, such as day-care centers and clandestine drug labs.

Fire Hazards

• Most fires in SFDs start in the vicinity of cooking or heating appliances. Potential for ignition exists from space heaters, pilot lights, electrical equipment, and smoking materials.
• Vertical and horizontal openings allow smoke and fire to enter and attack the structure.
• Fire that has entered these voids will necessitate the opening of floors, ceilings, and walls.
• A typical SFD has a low fire load, requiring 10 gpm per 100 sqft.
• Vinyl and asphalt siding may contribute to vertical and horizontal fire spread creating a severe exterior exposure problem.
• Improper fireplace installations may compromise the integrity of the components, allowing fire or heat to escape and ignite surrounding combustible members.

Rapid Fire Events

• The potential exists for flashover to occur in SFDs depending on the amount and type of combustible materials, rate of the burning materials' heat release, and an adequate supply of oxygen allow a fire to progress rapidly to the flashover stage.

Collapse

• Most modern SFDs are constructed of lightweight materials that do not withstand degradation from long-term fire exposure.
• Most of the brick on these buildings is veneer which may easily collapse under fire and master-stream conditions.
• Interior compartmentalization can provide firefighters operating on the top floor with areas of haven to position and continue firefighting operations.
• Roof features such as perpendicular gables and dormers often fall away from the building, creating an exterior collapse hazard.

Basements

• Operations in SFD basements can pose hazards due to stairwell design, limited ventilation, and limited means of ingress and egress.
• Finished basements may have unfinished utility rooms located under an SFD's main entrance.

Utilities

• Suspect overhead electrical service wires to a dwelling.
• If the size of estate homes may require commercial utility meters and electrical transformer box.
• More than one water meter may supply these structures, one at each end of the home.
• Interior fuel oil tanks and natural meters can become hazardous if exposed to fire, fuel oil tanks will have a fill pipe and vent located on an outside wall near the tank, while an interior gas meter will have a vent and may have a gray gas pipe going through an exterior wall to the interior meter's location.

Fire Operations

• Establishes Command of the incident by the first command officer to arrive on-scene:
  • Evaluate the need for additional alarms and rapid intervention team (RIT) resources commensurate with the situation's severity.
• Strategic positions for additional command officers include:
  • Division supervisor.
  • Group supervisor.
  • Branch director.
  • Section chiefs.
• Personnel should conduct a thorough primary search and contain and extinguish interior fire.
• Focus primary search operations on the area near the fire as well as bedrooms and means of egress.
• Horizontal fire spread represents a concern in SFDs that are located close to others.
• Cue the IC to request a second alarm if there are:
  • Known rescues.
  • Fire in two separate and adjacent SFDs.
  • Fire in an estate home.

Operational Communications

• Communicate a water supply report to the second due engine company, the report should identify the location and method of the hose lay.
• Utilize a forward (i.e., straight) hose lay, when possible, while maintaining unimpeded access for subsequently arriving truck companies.
• The first-arriving unit officer should provide the first due command-level officer the following information in the on-scene report:
  • Unit identification and the side of structure where the apparatus is positioned.
  • Building height.
  • Occupancy type.
  • Detailed report of evident conditions, including side of structure where conditions are evident, quadrant location, and conditions description.
• During the size-up, unit officers should complete a 360-degree lap of the structure and use a thermal imaging camera. The officer should also use the lap to determine the following:
  • Number of above-grade floors in front and rear.
  • Specific location of fire, if visible.
  • Presence of a basement, conditions present in the basement, and location of basement access.
  • Floor labeling.
  • Hazards observed.
  • Occupant status.
  • The need for additional resources.
• Unit officers should provide ongoing situation reports to ICs as their unit completes their tasks or when they require assistance to achieve their unit's objectives.
• Ongoing situation reports should take the form of a conditions, actions, needs (CAN) report.

Hoseline Selection and Advancement

• Consider a fire's intensity, size, and location, together with available staffing, when determining the initial hoseline.
• The initial hoseline for most SFD fires should be the 1 ¾" hoseline.
• The crew may also deploy this hoseline to perform a quick exterior knock on the fire before transitioning to the interior.
• Consider using large-caliber handlines and smooth-bore nozzles for well-advanced fires in SFD structures, and strongly consider using master streams when fires have reached advanced stages and no life hazard exists.
• The second line for most fires in an SFD should be the 1 ¾" handline.
• Additional consideration for second line in protecting the crew searching above.
• Line at base of the the stairs on fire floor, to observe fire conditions

Aerial Master Streams

• Influenced by building characteristics and scene geography, with hose stream directed parallel to and along the underside of the pitched roof.
• Use does not preclude deployment of smaller caliber handlines.

Attic Fire

• Fire can come from the basement/living area, interior fire, exterior fire, electrical fires, lightning, or work from roofers.
• The most operationally efficient position involves opening the top-floor ceiling and attacking the fire horizontally.
• Directing hose steams straight up into the space is ineffective.

Sweeping the Eaves and Soffit Attacks

• Rapid water application to knock down the exterior fire represents a critical part of any attempt to control not only the fire's spread to adjacent structures, but also its migration into an exposed building's interior.
• Firefighters can prevent fire from extending into the attic by sweeping the eaves with hose streams directed at the underside of the soffit and parallel to the wall.

Basement Fires

• Poses unique hazards and challenges due to limited access points and the potential for unimpeded fire impingement on the above floor's structural support.
• Officers must determine the location and extent of the fire, building construction, hazards, and points of basement access.
• Must coordinate ventilation of the basement and the floors above, and exterior entrance if available
• First lines best addresses the incidents needs by an exterior basement entrance for fire attack, or utilizing a fire stream to reach to protect the interior stairs and upper floors.
• Should check early for vertical extension through the stud bays in the exterior walls for an SFD with a balloon frame.
• Should expect fire to extend to all floors and the attic.

Basement Fire With an Exterior Entrance to the Basement

• For a basement fire, the preferred point of attack for the initial handline is an exterior entrance, using straight or solid fire streams to avoid steam conversion forcing it up to the stairs.
• Personnel positioned to contain and protect above floors on stairwell.

Basement Fire With No Exterior Entrance to the Basement

• Consider applying water to the basement from the exterior to knock down the fire, even if it means cutting into the structure from the outside
• Direct a fire stream through a basement window
• Make sure basement doors are open so as not to block access, also consider structural stability, life hazard, and fire conditions.

Deck Fires

• Prioritize positioning a hoseline on the structure's deck side to extinguish fire on the deck, soffit, and eaves.

Exterior Fires Extending Into the Dwelling

• Exterior fires can quickly ignite vinyl siding and exterior sheathing and run up the exterior through the soffit.
• Progress fast to multiple floors
• Coordinate operation amongst first arriving officers and special service unit.

Garage Fires

• Consider fire conditions, garage location, the presence of windows, and the status of the overhead garage door to determine appropriate fire attack tactics.
• Attached garage fires sometimes extend to upper floors and attics.
• Crews operating directly above a garage fire should exercise caution because the fire below them may directly access the floor members supporting them.

Wind-Driven Fires

• Deadly flow-path for blowtorch-effect flames and untenable temperatures
• Conditions require 10-20 mph winds
• 5 situations must exist: Fire in structure, failed open window/door, wind on structure exterior, secondary failed door from same fire area, unobstructed path from fire to the secondary open

Balloon-Frame Construction Fires

• Overhaul is often more challenging in balloon-frame dwellings due to the use of plaster and lathe construction.

Estate Home Fires

• Houses footprint may prevent arriving engine officer from surveying entire first floor, a second opinion from crew is needed.

Cluster Home Fires

• Can challenge the first-alarm, exposures present a major problem due to the proximity of adjacent structures

Fire Operations Resources

• Composed of 4 engines, 2 Trucks, 1 rescue, 1 ems, 2 battalion chiefs
• Fires outside hydrangeas should have 3 tankards

First Due Engine

• All other companies should bring forcible entry tools.

Operational Considerations

Forcible Entry

• can facilitate ventilation or adversely the fires path way, crews must be aware of what they are doing.

Ladder Deployment

• At an SFD fire should be performed on all available sides of all above-ground floors with attention on bedroom windows.

Search and Rescue

• Area closest to fire floor is more dangerous, personnel doing should check areas, and means of egress first.

Ventilation

• Managed with personnel managing the openings, also a variety of actions can cause ventilation.

Horizontal Vent

• Can be an important yet dangerous tactic, must be coordinated with attacking team.

Vertical Vent

• Ordered by command using common tactics.

Hoarding Conditions

• Compulsive holding disorder, accumulating belongings that have no apparent value or use, access to the structure is most likely delayed.