Rightways: Structural Integrity & failure

Structural integrity and failure is an aspect of engineering which deals with the ability of a structure to support a designed load (weight, force, etc...) without breaking, tearing apart, or collapsing, and includes the study of breakage that has previously occurred in order to prevent failures in future designs.

Structural integrity is the term used for the performance characteristic applied to a component, a single structure, or a structure consisting of different components. Structural integrity is the ability of an item to hold together under a load, including its own weight, resisting breakage or bending. It assures that the construction will perform its designed function, during reasonable use, for as long as the designed life of the structure. Items are constructed with structural integrity to ensure that catastrophic failure does not occur, which can result in injuries, severe damage, death, or monetary losses.

Structural failure refers to the loss of structural integrity, which is the loss of the load-carrying capacity of a component or member within a structure, or of the structure itself. Structural failure is initiated when the material is stressed beyond its strength limit, thus causing fracture or excessive deformations. In a well-designed system, a localized failure should not cause immediate or even progressive collapse of the entire structure. Ultimate failure strength is one of the limit states that must be accounted for in structural engineering and structural design.

These articles explain the inspection, detection, diagnosis, and repair of all types of structural defects on residential and light commercial buildings and will answer most homeowner concerns. We address brick and other masonry structures, wood frame structures, log homes, modular and factory built homes, even mobile homes.

Chimneys, crawl spaces, decks, building flood damage, foundation crack and movement damage, rot or insect damage, sink holes, and water entry are examples of topics for which InspectAPedia provides inspection, diagnosis, and repair advice. Our page top photo illustrates Story Land[26] a remarkably askew wood-framed structure that would have been quite challenging to frame.

Guide to Detecting & Evaluating Structural Defects: Inspection, Diagnosis, & Repair of Settlement, Improper Construction, Rot & Insect Damage to Buildings

Articles found in this section address just about all types of residential & light commercial building structural construction, inspection, diagnosis & repair topics such as foundation damage, leaning, buckling, bowing, and cracking, FRT plywood failures, chimney inspections & safety concerns, causes and cures for rot, mold, & termites in buildings, sinkholes at building sites, stair and rail fall & trip hazards, & also special inspection methods for mobile homes.

Most structural problems can be avoided by proper design and planning; but structural failures have been common for a long time, and sometimes are costly to handle properly.

The sketch at left( courtesy Carson Dunlop) names the major structural components of a typical wood frame house set on a masonry foundation.

Structural Defect Recognition, Repair, Prevention for Building Structures, & Building Structural Failures

This photo of the leaning tower of Pisa was sent to us by our friend Tom Smith who knows a crooked building when he sees one. Smith points out that the problems with the Tower have been known for generations and must have been apparent even during construction, as the upper level was constructed with an offset to try to re-balance the structure.
Modern reinforcement has permitted removal of cables that used to be tied to the tower of Pisa. As Bernie Campbalik says about old buildings, "Yep, we had guys like that back then too."

ARCHITECTURE & BUILDING COMPONENT ID - series of articles providing photo and drawing aids to architectural type and age of buildings and building components.
Balloon Framing: see Framing Methods
BASEMENT WATERPROOFING and FOUNDATION WATERPROOFING collect articles on keeping water and moisture out of buildings
BASKETBALL MOLD SYNDROME - BBMS - sudden attention to old clues in buildings makes them seem brand new to some observers
Best Practices Guide to Residential Construction - Steven Bliss Book Review by DJ Friedman
Chernobyl Nuclear Plant this interesting document describes serious flaws in the construction of the Chernobyl Nuclear Facility, conditions which were discussed among Russian authorities long before the Chernobyl nuclear disaster that occurred in the Ukraine in 1986

Metal chimney during installation (C) D Friedman

Chimneys, flues, wood stoves & fireplaces: chimney inspection, defects, safety concerns, Articles about Chimney Inspection, Collapse, Damage, Repair
- Bracing & Support for Chimneys - bracing needed at chimneys (just below)
- BRACKET CHIMNEY COLLAPSE & FIRE RISKS - what is a "bracket chimney" and where are they found and why do they collapse
- Chimney Collapse Hazards - Main Article
- Chimney Movement Causes - what causes chimney separation, leaning, or curving, what can we see outside
- Chimney Movement - Indoor Evidence - what can we see indoors that tells us that chimney or fireplace movement are occurring?
- Chimney Movement - Outdoor Evidence is a guide to recognizing outdoor evidence of chimney movement
- Chimney Movement is Ongoing - Evidence is a guide to recognizing when chimney movement has been ongoing rather than a single or initial settlement or movement event.
- Chimney Crack Detection & Diagnosis - what causes cracking in brick chimneys, how dangerous is it?
- Cracked Concrete Block Chimneys - an example of cracking in a masonry block chimney exterior
- Curved Brick Chimneys - what causes curving in brick chimneys, how are they evaluated and repaired?
- DRY-IN, DEFINITION of - what is dry in or dry box in building construction and what building steps must have been completed to reach dry in status?
- Earthquake or Storms can Cause Chimney Collapse
- Foundation Support for Masonry Chimneys
- CHIMNEY LEANING, REPAIR OPTIONS - how do we stabilize and repair a moving chimney, when does it need replacement, what are the alternatives?
- Loose Wobbly Chimneys need bracing or lateral support to avoid collapse
- Rooftop View Turns to Darkness a news report of a person who was trapped inside of a collapsing chimney is in our footnotes
- Split Openings in Brick Chimneys & Chimney Collapse Risk - we describe a case of an imminent catastrophic chimney collapse - SPLIT OPENINGS in BRICKS, CHIMNEY COLLAPSE

Deck & Porch Construction Guide - Deck & Porch construction details for safe, durable structures. Also see DECK COLLAPSE Case Study and DECK FLASHING LEAKS, ROT Case Study
ENERGY SAVINGS in BUILDINGS - articles on insulating, finding and fixing air and heat leaks, ventilation, etc. for energy efficient buildings
Flood Damage Control - FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
Action Guide after Flooding: First Priorities of Action in Response to Building Flooding
Cracks in Concrete Floors & Slabs, how to diagnose, evaluate, & repair slab cracks

Pier construction, Northern Maine (C) D Friedman

Flooded Building Mold Prevention how to respond to avoid mold
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP - see list of detailed articles & advice found here
Flooded Septic Systems Septic Systems what to do after a septic system has been exposed to flooding
FLOOD VENTS & FLOOD PORTS to avoid structural damage during building flooding, flood venting, flood ports, or flood gates on buildings
FOUNDATION CRACKS & DAMAGE GUIDE - Foundation Inspection, Materials, Defect Diagnosis, Repair Guide, how to inspect and diagnose foundation problems, in-depth diagnosis, and evaluation of all types of structural and non-structural cracks in residential foundations [Brick, Concrete, Masonry Block, Stone]
Foundation Inspection Methods
Site Factors Affecting Foundations
Foundation Construction Materials how to identify different materials and types of foundation, how to recognize the effects of sequence of construction on building durability

FOUNDATION FAILURES by TYPE & MATERIAL - see detailed links at page top & left
FOUNDATION DEFECTS OF OMISSION how to recognize things that were left out, like footings, reinforcement, soil compaction, during foundation construction
FOUNDATION CRACK DICTIONARY how to recognize and diagnose different types of foundation cracks, movement, damage, by the size, shape, location, pattern of cracks
CONCRETE SLAB CRACK EVALUATION how to recognize and diagnose different types of slab or concrete floor cracks and movement
FOUNDATION FAILURES by MOVEMENT TYPE how to recognize an diagnose different types of foundation damage by the kind of movement which has occurred
FOUNDATION BULGE or LEAN MEASUREMENTS a simple procedure for documenting the amount of lean or bulge in a foundation or other building wall
FOUNDATION MOVEMENT ACTIVE vs. STATIC how to determine if foundation movement was a one-time event or an ongoing problem
FOUNDATION DAMAGE SEVERITY some rules of thumb for deciding how much foundation movement requires further action
FOUNDATION DAMAGE REPORTS how to report foundation inspection results and damage
FOUNDATION REPAIR METHODS a catalog of methods used to repair damaged foundations and masonry building walls
Foundation Crack Repairs: How to Seal Cracks in Concrete a description of various products and methods used to seal or repair cracks in poured concrete walls, foundations, floors, & slabs.
Foundation Crack Repair Using Polyurethane Foam to stop basement or crawl space leakage
FOUNDATION INSPECTION STANDARDS a definition of scope of what a foundation inspector is required to observe and report

Framing & Wood Beams / Timbers Damage Inspection, Diagnosis, Testing, Repair

Photograph of severe roof structure damage from an unattended roof valley leak in a historic home.

FRAMING DAMAGE, INSPECTION, REPAIR - see detailed links for building framing, diagnosis, and repair at the "More Reading" links at the bottom of this article . Our photo (left) illustrates site built truss construction in a tango hall in Buenos Aires, Argentina. See these articles related to the assessment of wood framing, timbers, & structural members
CONNECTORS, FASTENERS, TIES - where to buy, how to install, how to use structural connectors like joist hangers, rafter ties, framing connectors, anchors
- Cracks, Checking or Splitting Beams & Log Homes
- FIRE DAMAGE vs MOLD DAMAGE - how to distinguish between fire damage and black mold on building surfaces, how to test for mold, use of sealants and paints after a fire or after a mold cleanup
- ROT, FUNGUS, TERMITES
- ROT RESISTANT LUMBER
- ROT, TIMBER FRAME
- ROT, TIMBER ASSESSMENT
- STRUCTURAL WOOD ASSESSMENT
Fire Retardant Treated FRT Roofing Plywood Failures inspection, detection, testing of defective FRT plywood roof sheathing
HOPPUS MEASURER - early carpentry & construction measurement guides & tools, history, photos, & excerpts from Hoppus's Measurer
INSECT INFESTATION / DAMAGE - wood destroying insect inspection, diagnosis, evaluation, repair, and prevention at buildings
Log Home Guide a guide to inspection, diagnosis, & repair of log homes, antique or old log cabins, modern kit log homes, vertical log construction, horizontal log construction, log checking, log home leaks, log home rot, log home sealants, gaskets, and coatings.
Mobile Home Inspections manufactured homes or "trailers" require special procedures
NOISE / SOUND DIAGNOSIS & CURE includes a discussion of the sources and cures of sounds in buildings
Post and beam framing: see Framing Methods

WOOD DESTROYING INSECTS carpenter ants, powder post beetles, & other wood destroying organisms
Sears Houses: How to identify Sears catalog kit houses photos and tips for identifying these interesting homes.
Sink Holes: Can X-Ray Vision [Advanced Building & Building Site Inspection Techniques] Warn of Sink Holes? in Florida or elsewhere

STAIRS, RAILINGS, LANDING INSPECTIONS, CODES - stair construction dimensions and specifications, stair codes
Stairs and Railings: A Checklist for Stair, Railing, Landing Safety Inspections

TIMBER FRAMING, ROT and TIMBER ASSESSMENT - Timber Frame Construction, Barn Collapses, Timber Frame Rot: post and beam framing history, inspection, diagnosis, repair
SOLAR ENERGY SYSTEMS Solar house designs, problems, retrofits, optimization
TERMITE SHIELDS vs TERMITICIDE - how to avoid termite damage to buildings that use foam board insulation at the foundation or underneath stucco.
THERMAL EXPANSION of MATERIALS how temperature changes affect building materials and cause building leaks or other failures
Trailer vs Mobile Home vs Modular vs Panelized Construction an explanation of terms and how to identify these structures.
WATER ENTRY in BUILDINGS series of articles on the causes and cures of high indoor moisture, wet basements, wet crawl spaces, and moisture related problems like attic condensation and mold.
X-Ray Vision for Home Inspection: [Advanced Building & Building Site Inspection Techniques] - Developing your X-Ray Vision, Levels of Fear, and how to use them to find and report significant, hidden problems on Buildings or in the inspection of almost any complex system
X-Ray Vision for Home Inspection: a Power Point Presentation© of the X-Ray Vision Home Inspection class detailed-text shown above.

Rot, fungus, Termites, Carpenter Ants, Powder Post Beetles, & other Wood Destroying Organisms

Buckled siding at ground level indicates sill crushing (C) Daniel Friedman

Our photo (left) illustrates a combination of factors leading to a strong indication of serious structural damage at a home: aluminum siding at ground level (risk of insect attack) combined with buckled siding at the bottom course (a condition that only occurs long after original construction) point to crushed wooden sills under this structure, most often due to insect attack or rot or both.

INSECT INFESTATION / DAMAGE - complete guide to wood destroying insect inspection, diagnosis, evaluation, repair, and prevention at buildings
The Sick House/Sick Building Information Website Organized, un-biased, in-depth advice about mold, allergens, and other indoor contaminants: finding, testing, cleaning, clearance testing, and preventing mold, mildew, wood destroying (rot) molds (fungi). Explains how to assure that testing for toxic or allergenic molds is performed using valid field and lab methods. Advice and test procedures are provided for odors and odor source detection, toxic gas testing and gas source identification.
"House Eating Fungus" Meruliporia incrassata (also called "Poria" the house eating fungus) in the U.S. or Serpula lacrymans in Europe) can cause severe structural damage. Evidence of hidden "poria" may be found by expert inspection methods which include tracing sources and paths of probable Building leaks and moisture traps. Further, careful indoor particle sampling methods can often permit the presence of this mold to be identified in the laboratory.
WOOD DESTROYING INSECTS carpenter ants, powder post beetles, & other wood destroying organisms

Continue reading at BRICK FOUNDATIONS & WALLS or select a topic from the More Reading links shown below.

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STRUCTURAL INSPECTIONS & DEFECTS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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Sunday 12 April 2015

Building structural integrity & failure: problems, inspections, damages, defects, testing, diagnosis, repair

Framing & Wood Beams / Timbers Damage Inspection, Diagnosis, Testing, Repair

Rot, fungus, Termites, Carpenter Ants, Powder Post Beetles, & other Wood Destroying Organisms

Suggested citation for this web page

More Reading