HMM Reference NIST Technical Note 2205: Item 1 Skylight

Photo 

5810

Damaged skylight

Skylight with multi paned 

tempered glass

Item 1 Skylight – Skylights can melt or break from heat and allow ember intrusion. 

Damaged skylight

Damaged plastic skylights

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 1: Skylight 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 2 Roof to Skylight Flashing

Item 2 Roof to Skylight Flashing – Flashing to protect sides of skylight to prevent against combustible debris ignition and embers.

Insufficient flashing Flashing around skylight

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
Installation Cautions 

 Fire Hazards 1. Debris accumulation on back

or surrounding skylight panels.

1. Use fire resistant caulking2. No combustible material

should be exposed. 

· Hardening Action: Check for standard metal flashing and that no exposed wood is present, repair as necessary. · Applicable Conditions: Lack of metal flashing around skylight · Performance Goal: Prevent ignition of combustible skylight framing Color Key: · Brown: wood

· Gray: Metal Step Flashing· Black/Dark Gray: Counter Flashing 

e: A 

/1 1 2 1
HMM Reference NIST Technical Note 2205: Item 3.1 Roof Assembly Details (Flashing)

No flashing

No flashing

Item 3.1 Roof Assembly Details (Flashing) – Flashing to protect against ignition by combustible debris and embers.

No flashing

6” tall

flashing

(illustrated)

6” tall

flashing

(illustrated)

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
Fire Hazards 1. If flashing is added on top of existing siding, siding can still

ignite if the surrounding ignitesand risk igniting the roof 

6-inch 

sting 

and 

· Hardening Actions: Metal flashing at roof-to-wall joint · Applicable Conditions: Combustible siding at roof-to-wall intersection · Performance Goals: Prevent ignition of roof from burning accumulated debris Installation Cautions 

ing), 

e: A 

 1/1 

1 1 1. Use fire resistant caulking to seal flashing and do not leave combustibles exposed.
HMM Reference NIST Technical Note 2205: Item 3.2 Roof Assembly Details (Dormers)

Item 3.2 Roof Assembly Details (Dormers) – Flashing and ignition resistant siding to protect dormer from ignition by combustible debris 

and embers. 

Ignition resistant

siding (illustrated)

Combustible 

siding

6” tall flashing

(illustrated) No flashing

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 3.2: Assembly Details (Dormer) 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 4 Solar Panel Raised Up

Item 4 Solar Panel Raised Up – Low curved edge can trap debris.

Low curved edge Large gap

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 4: Solar Panel Raised Up 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 5 Roof Covering (Old Wood Shake) 

Item 5 Roof Covering (Old Wood Shake) – Old wood and cedar roof materials are a high ignition risk.

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.

Photos pending.
There is no CAD drawing for 

Item 5: Roof Covering (Old Wood Shake) 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 6 Roof Covering (Classes B and C) 

Item 6 Roof Covering (Classes B and C) – Hardened roof materials like metal and Spanish tile prevent ignition. 

Metal roof

Spanish tile roof with sealed bird stops

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 6: Roof Covering (Classes B and C) 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 7 Roof Covering with Openings 

Photo 4281

Roof deck exposed Roof deck not exposed

Item 7 Roof Covering with Openings – Roof deck exposed when roof covering material or flashing does not extend past the roof deck 

or is not present. 

Roof edge protected Roof deck exposed, with metal flashing no metal flashing

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 7: Roof Covering with Openings 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 8.1 Gutter Mesh Covering

Damaged vinyl gutter cover

Metal gutter cover

Damaged vinyl gutter cover

Item 8.1 Gutter Mesh Covering – Noncombustible gutter covers help prevent combustible debris and embers from entering gutter.

Metal gutter cover

Damaged vinyl gutter cover

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 8.1: Gutter Mesh Covering 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 8.2 Metal Drip Edge 

Item 8.2 Metal Drip Edge – Metal drip edge protects roof materials. 

No drip edge and no flashing Metal drip edge

No drip edge and no flashing

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 8.2: Metal Drip Edge 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 8.3 & 9 No Gutters

Shingle folded over edge

No gutter and roof

material is exposed

Item 8.3 & 9 No Gutters – Roof edge without gutters can leave combustible roof materials exposed. 

No gutter but roof material is not exposed

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
 58) 

e: A 

1/1 · Hardening Actions: Remove gutter & add metal sheathing if fascia does not cover roof sheathing · Applicable Conditions: Combustible gutter cover, no gutter cover, and/or exposed sheathing · Performance Goals: Prevent ignition from embers and prevent accumulation of embers at sheathing intersection Installation Cautions

Color Key: · Red: Painted wall · Black: Roof tiles · Brown: Wood 

Fire Hazards 1. Flammable debris can accumulate in rubble filter and ignite close to house if not cleaned 

- less 

lable 

surface 

.01.6 · Gray: Metal flashing · Light Gray/White: Pipe · Mottled: Rubble filter 1
HMM Reference NIST Technical Note 2205: Item 10 Height of Wall Assembly

Burned 

unprotected 

deck post

Noncombustible

material

Ignited 

wood wall

at ground

Item 10 Height of Wall Assembly – Hardening exterior walls and deck supports 2 ft above ground will prevent windblown debris and embers 

from igniting the wall.

Source: ADAI, Univ of Coimbra

Stone 

deck post

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
HMM Reference Installation Cautions

Notes Fire Hazards

24.00 in

•

•

•

Hardening Action: Replace exterior wall covering with 

noncombustible material for first two ft (from ground) and add 

metal flashing to protect bottom edge sheathing 

Applicable Conditions: All sheathing within two feet of the 

ground

Performance Goals: Prevent windblown debris and embers 

from igniting the wall

NIST Technical Note 2205,

Height of Wall Assembly, 

Table A, Item 10 (Page 58)

• Metal flashing is required for all

claddings, including ignition 

resistant materials

1. Seal noncombustible wall

covering to house exterior.

1. If superheated by close proximity

to flame, metal flashing risks 

igniting siding

Project: HMM House Size: A

Scale: 1:60 Sheet: 1/1

1

1
HMM Reference NIST Technical Note 2205: Item 11 Ridge Vent

Item 11 Ridge Vent – Metal ridge vents prevent ember intrusion into house. 

Metal ridge vent

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 11: Ridge Vent 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 12 Off-Ridge Vents

Item 12 Off-Ridge Vents – Apply fine metal mesh screens to roof vents to prevent ember intrusion.

Off-ridge vents with fine

metal mesh screen (not visible)

Vents without fine metal mesh screen

Off-ridge vent without fine metal mesh screen 

exposed roof to embers causing damage

Off-ridge vents with fine metal mesh screen (not visible)

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 12: Off-Ridge Vents 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 13 Gable Vent

Item 13 Gable Vent – Apply 1/8th inch fine metal mesh screen inside gable vents to prevent ember intrusion. 

No metal mesh

screen behind

vent cover

No metal mesh screen behind vent cover

Fine metal mesh screen behind 

vent cover (not visible)

Fine metal mesh

screen behind 

vent cover

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 13: Gable Vent 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 14.1 Under Eave Vent (Vertical)

Item 14.1 Under Eave Vent (Vertical) – Keep vents clean, cover with a 1/8th inch fine metal mesh screen, and seal vent with fire-resistant 

caulking.

Damage above and behind vent with large metal mesh screen

Screened vent with fine

metal mesh and vent 

sealed with fire 

resistant caulking

Screened vent with fine metal mesh and

vent sealed with fire resistant caulking

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 14.1: Under Eave Vent, Vertical 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 14.2 Under Eave Vent (Horizontal)

Photo 1859

Vinyl vent in eaves

Vinyl vent in eaves

Item 14.2 Under Eave Vent (Horizontal) – Keep vents clean and cover with a 1/8th inch fine metal mesh screen and sealed with fire-resistant 

caulking.

Screened vent with fine metal mesh and vent sealed with fire 

resistant caulking

Screened vents with

fine metal mesh and

vent sealed with fire 

resistant caulking

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 14.2: Under Eave Vent, Horizontal 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 15.1 & 15.2 Crawl Space Vent

Screened vent with fine metal mesh spacing

Item 15.1 & 15.2 Crawl Space Vent – Keep vents clean and cover with a 1/8th inch fine metal mesh screen to prevent ember intrusion.

Screened vent but metal mesh spacing is too large

Screened vent but metal mesh spacing is too large Screened vent with fine metal mesh spacing

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 15.1,15.2: Crawl Space Vent 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 15.3 No Crawl Space Vent

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.

Photos pending.
There is no CAD drawing for 

Item 15.3: Crawl Space Vent, None 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 16 Dryer Vents

Item 16 Dryer Vents Caption – Hardened dryer vent exterior, use a 1/8th inch fine metal mesh screen, and metal flapper to prevent ember

intrusion.

Plastic cover for dryer vent without fine metal mesh screen

Top flap opened to show dryer duct without screen

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 16: Dryer Vents 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 17 Makeup Air Intake

Item 17 Makeup Air Intake – Large intake vents should have a 1/8th inch fine wire mesh screen to prevent ember intrusion.

Various vents should have fine metal mesh screens

Various vents should 

have fine metal mesh screens

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 17: Makeup Air Intake 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 19 Other Attachments to Mobile Home

Photo 3500

Item 19 Other Attachments to Mobile Home – Noncombustible barrier between mobile home attachments and house exterior.

No barrier at 

attachment to 

house

No barrier at 

attachment 

to house

6” metal flashing

as barrier (illustrated)

6” metal flashing

as barrier (illustrated)

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 19: Other Attachments to Mobile Home 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 21 Window Screen

Item 21 Window Screen – Window screens reduce radiation to pane glass and prevent ember intrusion before and after glass failure.

Screen 

prevents 

embers from

penetrating to 

window and 

frame

Screen falls when

vinyl frame fails

Screen reduces

radiation exposure

to window glass

Unscreened side

with broken window

exposing interior

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 21: Window Screen 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 22 Window (Single Pane)

Item 22 Window (Single Pane) – Replace with non-combustible frame and double pane tempered glass window.

Broken and missing glass

exposes home interior

Double pane tempered 

glass window with 

noncombustible frame

Broken and missing glass

exposes home interior

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 22: Window (Single Panel) 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 23 Window (Double Pane)

Item 23 Window (Double Pane) – Double pane provides protection against radiation and ember intrusion.

Broken and missing glass

exposes home interior

Broken and missing glass

exposes home interior

Screen reduces 

radiation exposure

Screen reduces 

radiation exposure

Double pane tempered glass 

window with ignition resistant frame

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 23: Window (Double Pane) 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 24.1 Exterior Door (Non-Sliding)

Item 24.1 Exterior Door (Non-Sliding) – Combustible door and door jamb can ignite; noncombustible door materials prevent ignition. 

Wood door and wood

frame ignited

Hardened door and 

door jamb prevent ignition

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 24.1: Exterior Door (non-sliding) 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 24c Exterior Door (Sliding)

Photo 2047

Item 24c Exterior Door (Sliding) – Noncombustible sliding doors reduce risk of ignition to home interior.

Non wood sliding door

Non wood sliding door

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 24c: Exterior Door (Sliding) 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 25 Wood-Frame Screen Door

Item 25 Wood-Frame Screen Door – Noncombustible framed metal screen doors reduce risk of ignition.

Metal screen door

Metal screen door

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 25: Wood-Frame Screen Door 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 26 Plastic Screen Door

Item 26 Plastic Screen Door – Replace plastic screen doors with metal screens and doors to reduce ignition risk.

Metal frame door with

damaged plastic screen

Metal door

with metal

screen

Metal door

with metal

screen

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 26: Plastic Screen Door 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 27 Garage Door

Item 27 Garage Door – Sealed garage doors with metal flashing along lower frame can reduce risk of garage ignition.

No flashing

on trim Unsealed gap

under door

Window

No windows

Sealed gap

under door

Flashing along

door trim

(illustrated) Damaged vinyl

window trim

Sealed gap 

around door

Flashing along

door trim

(illustrated)

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
· Hardening Actions: Add metal flashing at base of framing

for first 6 inches. Enclose bottom of door with metal flashing("C" channel) for 6 inches if door is not metal. Add fireresistant gasketing.

· Applicable Conditions: Wooden door or frame; no gasket· Performance Goals: Prevent ember intrusion and ignition

Installation Cautions 

1/1 

e: A Fire Hazards 1. If gaps are present or door is left open, embers may enter the garage

and ignite combustibles. 

1. Seal flashing to frame. 

1 1
HMM Reference NIST Technical Note 2205: Item 28.1 Deck Attached to Residence 

Item 28.1 Deck Attached to Residence – Ignition resistant deck material within 1 ft of house exterior can reduce risk of ignition. 

No barrier between 

combustible 

deck and 

residence

1 ft ignition resistant

barrier between deck 

and residence 

(illustrated)

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
Installation Cautions 

Color Coding Fire Hazards · Hardening Action: Replace walking surface boards with ignition resistant deck board for first 1 ft away from residence · Applicable Conditions: Combustible deck, stairs, and landing attached to residence · Performance Goals: Prevent ignition of deck and limit flame spread to exterior wall 

e: A 

/1 

must be

1. Decking beyond first 1 ft away

from residence, and any

combustible objects on deck,are still vulnerable to ignition.

· Gray: Metal flashing· Dark Brown: ignition resistant deck boards· Light Brown: existing decking material 1 1 ft
HMM Reference NIST Technical Note 2205: Item 28.2 Deck Attached to Residence

Item 28.2 Deck Attached to Residence – Replace combustible deck material with noncombustible material to reduce risk of ignition. 

Damaged combustible deck

Noncombustible deck with concrete steps and metal rail

Noncombustible

landing and steps

Source: ADAI, Univ of Coimbra

Damaged combustible deck

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
, 

e: A 

1/1 

Color Key: Fire Hazards · Hardening Action: Replace entire deck with ignition Installation Cautions resistant option (metal or other material) · Applicable Conditions: Combustible deck, stairs and landings attached to residence · Performance Goals: Prevent ignition of deck and limit flame spread to exterior walls

ICC

· Light Gray: Metal flashing on exterior of residence· Dark Gray: Metal deck framing· Black: Ignition resistant decking material 
HMM Reference NIST Technical Note 2205: Item 29 Deck-to-Wall Intersection

Item 29 Deck-to-Wall Intersection – Providing a 2 ft high noncombustible barrier up from deck along house exterior can reduce ignition.

Combustible siding above deck Noncombustible siding above deck (illustrated)

Photo 6596

Combustible deck ignited wall of defended house

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
Installation Cautions 

Fire Hazards 

e: A 

1/1 1. Wooden deck can ignite 2. Wooden part inside of cladding can ignite and potentially damage the house 2 

· Hardening Action: Replace bottom 2 feet of combustible siding with noncombustible (e.g fiber cement) and add metal flashing to protect exposed sheathing · Applicable Conditions: Combustible siding · Performance Goals: Limit ignition of exterior wall 1 2 ft 

2 ft
HMM Reference NIST Technical Note 2205: Item 30 Combustible Decks & Nearby Fuels

Wood pallet

fuel

Wood 

pile fuel

Item 30 Combustible Decks & Nearby Fuels – Remove combustibles around the house and away from the deck.

Noncombustible deck with limited fuel 

Area under deck clear of combustibles 

Extended concrete deck post footer

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 30: Combustible Decks & Nearby Fuels 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 31 Fence Attached to Residence 

Item 31 Fence Attached to Residence – Keep combustible fence away from house, use noncombustible fence within 8 ft of house. 

Metal fence not attached

to the house

Metal fence not attached 

to the house

Burned wood fence 

that was attached 

to the house

Burned wood fence

that was attached

to the house

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
Installation Cautions 

Color Key: Fire Hazards · Hardening Action: Replace with flame-retardant option (metal or other option), minimum 8 ft · Applicable Conditions: Combustible fence · Performance Goals: Prevent ignition of combustible fence from spreading to house 1. Do not use combustible materials to attach noncombustible fence to the house.

nces - 

le fences

um 8 ft

· Brown: Wood fence· Light gray: Metal fence· Mottled brown: Soil 

e: A 

1/1 

, 

1 1 · Red: Exterior wall siding · Gray: Metal flashing · Green: Lawn 8 ft
HMM Reference NIST Technical Note 2205: Item 32 Stairs Connected to Residence

Item 32 Stairs Connected to Residence – Use a noncombustible material for exterior stairs attached to noncombustible barrier/section between steps

and house and between handrails and house (min 1') or replace with noncombustible handrail.

Concrete steps

attached to house 

with metal rail

Tile steps attached to house

Burned wood 

stairs attached 

to house 

(defended by 

firefighters)

Destroyed wood 

stairs exposed 

house interior

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 32: Stairs connected to residence 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 34 Attached Retaining Walls

Item 34 Attached Retaining Walls – Replace retaining wall length equal to two times retaining wall height with noncombustible components.

Brick retaining wall attached to house

Stone retaining wall 

attached to house

Burned wood retaining wall 

Burned wood retaining wall 

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
· Hardening Actions: Replace retaining wall length equal to two times retaining wall height with ignition resistant components · Applicable Conditions: Combustible retaining wall withing two times the retaining wall height from the residence · Performance Goals: Prevent flames from retaining wall from igniting residence. 

retaining 

must 

o 8 ft Fire Hazards Installation Cautions 1. Seal retaining wall and house joint with ignition resistant material. 

e: A 

1/1 8 ft 1
HMM Reference NIST Technical Note 2205: Item 35 Combustible Furniture

Item 35 Combustible Furniture – Move combustible furniture away from house to reduce risk of home ignition from burning combustibles.

Combustibles moved

away from house

Combustibles moved

away from house

Burned lounge

chair cushion

Whicker chairs 

with cushions

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 35: Combustible Furniture 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 36 Pergola / Trellis

Item 36 Pergola / Trellis – Do not attach combustible materials to the house exterior; keep pergola / trellis 2 ft from home.

Metal pergola away from house

Wood pergola

attached

to house

Burned wood pergola and home at attachment

Burned wood 

post 

away from 

home

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 36: Pergola/trellis 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 37 Mobile Home Skirting

Item 37 Mobile Home Skirting – Noncombustible skirting can prevent mobile home underside from igniting and accumulating flammable

(windblown) debris.

Damaged skirting 

exposes underside

Damaged skirting 

exposes underside

Metal skirting 

protects underside

Despite exterior exposure, metal 

skirting protected underside

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 37: Skirting, Mobile Home 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 38 Mobile Home Crawl Space Access Hinged Door

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.

Photos pending.
There is no CAD drawing for 

Item 38: Space Access Hinged Door, Mobile Home 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 39 Mobile Home Crawl Space Vents

Item 39 Crawl Space Vents – Keep vents clean and covered with a 1/8th inch fine metal mesh screen to prevent ember intrusion. 

Enlarged image from above showing vent covered

with a 1/8th inch fine metal mesh screen

Vent openings are covered

with a 1/8th inch fine metal 

mesh screen

Vent openings are large, without fine metal mesh screen

Vinyl 

vent in 

skirting

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 39: Crawl Space Vents, Mobile Home 

Please see photographs for illustrations.
HMM Reference NIST Technical Note 2205: Item 40 Between Deck Boards

Item 40 Between Deck Boards – Insert metal flashing between deck boards and joists can reduce ignition between deck materials.

Metal flashing between deck boards 

and joists could reduce ignition

Image below was taken 

from underneath this 

wood deck

Note: Selected photographs are included to illustrate each HMM hardening item. Additional vulnerabilities or hardening items may be seen in the photographs, but those are highlighted within their specific HMM item.
There is no CAD drawing for 

Item 40: Between Deck Boards 

Please see photographs for illustrations.