Inspecting Inspecting StructureStructure

Prepared By: Marcia BelcherPrepared By: Marcia Belcher

The Structural InspectionThe Structural Inspection

• Structure includes:Structure includes:– Foundation & foundation wallsFoundation & foundation walls– Roof structureRoof structure– Wall, ceiling and floor Wall, ceiling and floor – Any load supporting element (columns, pilasters, beams, etc.)Any load supporting element (columns, pilasters, beams, etc.)

• Much of a home’s “skeleton” is hidden.Much of a home’s “skeleton” is hidden.

• Indicators like cracks on finished surfaces and signs Indicators like cracks on finished surfaces and signs of sagging/buckling can be signs of a structural of sagging/buckling can be signs of a structural failure.failure.

• Inspectors must learn to “read” visible signs of Inspectors must learn to “read” visible signs of trouble.trouble.

The Structural The Structural InspectionInspection

• Inspector should observe all aspects Inspector should observe all aspects of a home’s structural system that are of a home’s structural system that are available for inspection.available for inspection.

• Describe:Describe:– Type of constructionType of construction– Type of materials usedType of materials used

Objective: Identify major deficiencies in Objective: Identify major deficiencies in structure,structure,

structural assemblies & sub-assembliesstructural assemblies & sub-assemblies

Standards of Practice For Standards of Practice For StructureStructure

• Action Required:Action Required:– Probe components where deterioration Probe components where deterioration

is suspectedis suspected– Enter crawl spaces/attic spaces when Enter crawl spaces/attic spaces when

possiblepossible• Do no harm and stay out of DANGER!Do no harm and stay out of DANGER!

– Report water penetration or presence of Report water penetration or presence of moisturemoisture

– Report major deficienciesReport major deficiencies

Typical Major Typical Major DeficienciesDeficiencies

• Signs of problems:Signs of problems:– Movement of the entire structure or Movement of the entire structure or

partsparts– Distortion such as leaning, bowing or Distortion such as leaning, bowing or

saggingsagging– Failure of components Failure of components

(cracking/splitting)(cracking/splitting)– Water penetrationWater penetration– Deterioration of materialsDeterioration of materials

Inspecting Structure: Inspecting Structure: FoundationsFoundations• Typical Residential Typical Residential

Construction Methods:Construction Methods:

– Masonry block wallMasonry block wall– Poured wallPoured wall

Typical Foundation Drain Typical Foundation Drain MethodsMethods

• Exterior drain: Exterior drain: • Interior/exterior drain Interior/exterior drain

with bleederswith bleeders• Water drains to:Water drains to:

– - Exterior - Exterior ditch/channelditch/channel

– - Drywell >15’ - Drywell >15’ from homefrom home

– - Sump w/pump- Sump w/pump

Foundation drain problems are common & indicated by basement water/dampness.

Foundation WallsFoundation Walls

• Supports structure and transmits Supports structure and transmits weight to footing & soil.weight to footing & soil.

• Must resist lateral forces from soilMust resist lateral forces from soil– Must be protected from hydrostatic Must be protected from hydrostatic

force build-upforce build-up

Procedure For Inspecting Procedure For Inspecting FoundationsFoundations

• Start outsideStart outside– Watch for signs of settlement or movement Watch for signs of settlement or movement

(see below)(see below)

• Focus on:Focus on:– Ridge line of roofRidge line of roof– Racking of structureRacking of structure– Chimney pulling awayChimney pulling away– Warping of sidingWarping of siding– Cracks in foundation walls and exterior wallsCracks in foundation walls and exterior walls– Corners of building settlingCorners of building settling– Displacement of windows & doorsDisplacement of windows & doors

Ridge Line Ridge Line

Notice ends of ridge line drop off & window Notice ends of ridge line drop off & window displacement.displacement.

Indicates that foundation is/has been Indicates that foundation is/has been sinking at corners of bearing walls.sinking at corners of bearing walls.

Chimney TroubleChimney Trouble

Foundation of chimney is settling and Foundation of chimney is settling and creating tilt.creating tilt.

Twisting of Siding From Twisting of Siding From SettlementSettlement

Sill plate rotted due to moisture in the Sill plate rotted due to moisture in the crawl space.crawl space.

Structure settled to top of foundation Structure settled to top of foundation wall along this wall.wall along this wall.

Twisted Siding = Twisted Siding = SettlementSettlement

• What other signs do you see?What other signs do you see?

Movement of Foundation Movement of Foundation WallWall

Foundation of previous homeFoundation of previous home

Cracks in Brick VeneerCracks in Brick Veneer

• Step crack = corner of foundation Step crack = corner of foundation settlingsettling

The only way for this crack to occur is for the left aspect to translate downward relative to the right aspect of the wall.

Displacement of Displacement of WindowsWindows

• Distortion of windows/frames = Distortion of windows/frames = settlementsettlement

Openings that were once square will “rack” upon movement of the structure. Racking will turn square or rectangle into trapezoid.

Vertical & Diagonal Cracks Vertical & Diagonal Cracks in a Foundation Wallin a Foundation Wall

• Cracks are almost always a sign of Cracks are almost always a sign of settlementsettlement

• Settlement may be caused by:Settlement may be caused by:– Weak soils below allowing portions of Weak soils below allowing portions of

wall to sinkwall to sink– Excessively high loads on structure Excessively high loads on structure

failing the soils below.failing the soils below.

• Examples: Diagonal & Step CracksExamples: Diagonal & Step Cracks

Inspecting Foundation: Inspecting Foundation: InsideInside

General Guidelines For Foundation Cracks:General Guidelines For Foundation Cracks:

• Surface cracks that show no displacement are Surface cracks that show no displacement are usually related to shrinkage of materials and not usually related to shrinkage of materials and not structural.structural.

• Cracks less than ¼” wide are not likely signs of Cracks less than ¼” wide are not likely signs of structural damage, unless they are “active”structural damage, unless they are “active”

• Cracks over 3/8” should be examined as source of Cracks over 3/8” should be examined as source of a problem.a problem.

• Active cracks should be noted as a major defect.Active cracks should be noted as a major defect.

Active CracksActive Cracks

• Will have sharp “fresh” looking Will have sharp “fresh” looking edgesedges

• Will break new paint or mortar patchWill break new paint or mortar patch

Horizontal CracksHorizontal Cracks• Walls are designed to withstand lateral forces from soils.Walls are designed to withstand lateral forces from soils.• Horizontal cracking indicates that pressure against wall is too Horizontal cracking indicates that pressure against wall is too

great.great.• Causes:Causes:

– Improper backfilling techniques (excessive surcharge Improper backfilling techniques (excessive surcharge force)force)

(Lateral pressures from equipment too great for wall)(Lateral pressures from equipment too great for wall)– Water building-up behind wall (crack in lower 1/3)Water building-up behind wall (crack in lower 1/3)

(Hydrostatic force build-up)(Hydrostatic force build-up)

– Wet soils = frost expansion (crack in upper 1/3Wet soils = frost expansion (crack in upper 1/3))(Soil in frost zone freezes and expands laterally)(Soil in frost zone freezes and expands laterally)

FYI: Repair Method For FYI: Repair Method For Bowed WallsBowed Walls