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Building structural inspection, diagnosis, repair:
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.
Inspection, Diagnosis, & Repair of Building or Foundation Settlement, Improper Construction, Damage from Disasters, Rot & Insect Damage or other damage sources
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
The sketch above (courtesy Carson Dunlop Associates, a Toronto home inspection & education firm) names the major structural components of a typical wood frame house set on a masonry foundation.
To find what you need quickly, if you don't want to scroll through this index you are welcome to use the page top or bottom Seach Box to search InspectApedia for specific articles and information.
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."
CHERNOBYL NUCLEAR PLANT DISASTER 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
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]
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
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.
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
Rot, fungus, Termites, Carpenter Ants, Powder Post Beetles, & other Wood Destroying Organisms
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.
"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.
INSECT INFESTATION / DAMAGE - complete guide to wood destroying insect inspection, diagnosis, evaluation, repair, and prevention at buildings
SICK HOUSE SICK BUILDING INFORMATION
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.
Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
roof trusses and collar ties
(Dec 28, 2011) Anthony De Cesare said:
This house is constructed with roof trusses with partial conventional roof framing.
I have picture of the area of three collar ties are withdrawal from conventional roof rafters.
I'd like to see the pictures Anthomy
Comment: old barns
(Dec 30, 2012) Mac Arthur said:
Hi I see you took a picture of my Fathers barn in 2009! It is now completely down.
Thanks for the note, Mac Arthur. I'm not sure which barn you refer to as we've phographed hunderds of barns over several decades in several countries. But in Wappingers Falls NY I did notice that a barn we'd observed for some time had been taken down and apparently some of its timbers were to be re-used. If that's the barn to which you refer, we'd welcome hearing any history you can add - let me know the web page and image name for the barn to which you refer - that'd help too.
Question: deck ledger installation on balloon framed buildings
(Sept 17, 2014) steve said:
how does one install a ledger for a deck on a balloon framed house? can a few of the beams sent on top of the rock foundation?
I may be missing something but I'd think you'd bolt the deck ledger through to the studs if there were no rim joist in place.
(Apr 18, 2015) doublecheck said:
Thermographic Inspections Ottawa Valley
You have changed my mind.
Thank you for this
Ask a Question or Search InspectApedia
Questions & answers or comments about building structural problem inspection, diagnosis, & repair
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
 Bob Peterson, Magnum Piering - 800-771-7437 - FL*
 Arlene Puentes, ASHI, October Home Inspections - (845) 216-7833 - Kingston NY
 Greg Robi, Magnum Piering - 800-822-7437 - National*
 Dave Rathbun, P.E. - Geotech Engineering - 904-622-2424 FL*
 Ed Seaquist, P.E., SIE Assoc. - 301-269-1450 - National
 Dave Wickersheimer, P.E. R.A. - IL, professor, school of structures division, UIUC - University of Illinois at Urbana-Champaign School of Architecture. Professor Wickersheimer specializes in structural failure investigation and repair for wood and masonry construction. * Mr. Wickersheimer's engineering consulting service can be contacted at HDC Wickersheimer Engineering Services. (3/2010)
 *These reviewers have not returned comment 6/95
 Superior Walls of America Builder Guideline Booklet MAN 42-9000 booklet, [local copy] web-search 09/01/2010 original source (indirect link): http://www.superiorwalls.com/faq.php?&answers=1&details=53
Story Land, Story Land is an amusement center located in New Hampshire at
850 NH Route 16
Glen, NH 03838
603-383-4186 Website: http://www.storylandnh.com/contact.html
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Allen, Edward and Joseph Iano. Fundamentals of Building Construction: Fourth Edition. Hoboken: John Wiley & Sons, 2004. pg. 91 [LVL lumber]
APA - The Engineered Wood Association, 7011 So. 19th St., PO Box 11700, Tacoma WA 98411-0700, Tel: 253-565-7265. APA provides an HDO/MDO Plywood Product Guide that offers details about these products., provides an HDO/MDO Plywood Product Guide that offers details about these products. Product support help desk: 253-620-7400. Email the APA at firstname.lastname@example.org. Web search 09/13/2010, original source: http://www.pacificwoodlaminates.com/img/PDFs/PlywoodGuide.pdf
Design of Wood Structures - ASD, Donald E. Breyer, Kenneth Fridley, Kelly Cobeen, David Pollock, McGraw Hill, 2003, ISBN-10: 0071379320, ISBN-13: 978-0071379328
This book is an update of a long-established text dating from at least 1988 (DJF); Quoting: This book is gives a good grasp of seismic design for wood structures. Many of the examples especially near the end are good practice for the California PE Special Seismic Exam design questions. It gives a good grasp of how seismic forces move through a building and how to calculate those forces at various locations.THE CLASSIC TEXT ON WOOD DESIGN UPDATED TO INCLUDE THE LATEST CODES AND DATA. Reflects the most recent provisions of the 2003 International Building Code and 2001 National Design Specification for Wood Construction. Continuing the sterling standard set by earlier editions, this indispensable reference clearly explains the best wood design techniques for the safe handling of gravity and lateral loads. Carefully revised and updated to include the new 2003 International Building Code, ASCE 7-02 Minimum Design Loads for Buildings and Other Structures, the 2001 National Design Specification for Wood Construction, and the most recent Allowable Stress Design.
Diagnosing & Repairing House Structure Problems, Edgar O. Seaquist, McGraw Hill, 1980 ISBN 0-07-056013-7 (obsolete, incomplete, missing most diagnosis steps, but very good reading; out of print but used copies are available at Amazon.com, and reprints are available from some inspection tool suppliers). Ed Seaquist was among the first speakers invited to a series of educational conferences organized by D Friedman for ASHI, the American Society of Home Inspectors, where the topic of inspecting the in-service condition of building structures was first addressed.
Defects and Deterioration in Buildings: A Practical Guide to the Science and Technology of Material Failure, Barry Richardson, Spon Press; 2d Ed (2001), ISBN-10: 041925210X, ISBN-13: 978-0419252108. Quoting: A professional reference designed to assist surveyors, engineers, architects and contractors in diagnosing existing problems and avoiding them in new buildings. Fully revised and updated, this edition, in new clearer format, covers developments in building defects, and problems such as sick building syndrome. Well liked for its mixture of theory and practice the new edition will complement Hinks and Cook's student textbook on defects at the practitioner level.
Georgia-Pacific Building Products, 133 Peachtree Street NE, Atlanta, GA 30303. Telephone:
(404) 652-4000 , Wood Products: 800-284-5347. Gypsum Products: 800-255-6119. LVL lumber: GP-LAM, web search 09/14/2010, original source: http://www.gp.com/build/product.aspx?pid=1392
Laminated Veneer Lumber, Overview of the Product, Manufacturing, Market, Department of Forest Products Marketing, wood-Based Panels Technology, Finland [PDF] web search 09/14/2010, original source: http://www.hochstrate.de/micha/finnland/reports/replvl.html
Masonry structures: The Masonry House, Home Inspection of a Masonry Building & Systems, Stephen Showalter (director, actor), DVD, Quoting: Movie Guide Experienced home inspectors and new home inspectors alike are sure to learn invaluable tips in this release designed to take viewers step-by-step through the home inspection process. In addition to being the former president of the National Association of Home Inspectors (NAHI), a longstanding member of the NAHI, the American Society of Home Inspectors (ASHI), and the Environmental Standard Organization (IESO), host Stephen Showalter has performed over 8000 building inspections - including environmental assessments. Now, the founder of a national home inspection school and inspection training curriculum shares his extensive experience in the inspection industry with everyday viewers looking to learn more about the process of evaluating homes. Topics covered in this release include: evaluation of masonry walls; detection of spalling from rebar failure; inspection of air conditioning systems; grounds and landscaping; electric systems and panel; plumbing supply and distribution; plumbing fixtures; electric furnaces; appliances; evaluation of electric water heaters; and safety techniques. Jason Buchanan --Jason Buchanan, All Movie Review
Straw Bale Home Design, U.S. Department of Energy provides information on strawbale home construction - original source at http://www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10350
More Straw Bale Building: A Complete Guide to Designing and Building with Straw (Mother Earth News Wiser Living Series), Chris Magwood, Peter Mack, New Society Publishers (February 1, 2005), ISBN-10: 0865715181 ISBN-13: 978-0865715189 - Quoting: Straw bale houses are easy to build, affordable, super energy efficient, environmentally friendly, attractive, and can be designed to match the builder’s personal space needs, esthetics and budget. Despite mushrooming interest in the technique, however, most straw bale books focus on “selling” the dream of straw bale building, but don’t adequately address the most critical issues faced by bale house builders. Moreover, since many developments in this field are recent, few books are completely up to date with the latest techniques. More Straw Bale Building is designed to fill this gap. A completely rewritten edition of the 20,000-copy best--selling original, it leads the potential builder through the entire process of building a bale structure, tackling all the practical issues: finding and choosing bales; developing sound building plans; roofing; electrical, plumbing, and heating systems; building code compliance; and special concerns for builders in northern climates.
Ohawa, Ontario Wood Reference Handbook, p. 166, Canadian Wood Council, 1991
Sinkholes and Sudden Land Subsidence References, Products, Consultants
"A Hole in the Ground Erupts, to Estonia's Delight", New York Times, 9 December 2008 p. 10.
History of water usage in Estonia: (5.7 MB PDF) jaagupi.parnu.ee/freshwater/doc/the_history_of_water_usage_systems_in_estonia.pdf
"Quebec Family Dies as Home Vanishes Into Crater, in Reminder of Hidden Menace", Ian Austen, New York Times, 13 May 2010 p. A8. See http://www.nytimes.com/
"Quick Clay", Wikipedia search 5/13/2010 - http://en.wikipedia.org/wiki/Quick_clay
Florida DEP - Department of Environmental Protection, & Florida Geological survey (http://www.dep.state.fl.us/geology/default.htm) on Florida sinkholes: Effects of Sinkholes on Water Conditions Hernando County, Florida, Brett Buff, GIS in Water Resources, 2008, Dr. David R. Maidment, Photos - Tom Scott, Florida Geographic Survey - Web Search 06/09/2010 - http://www.dep.state.fl.us/geology/geologictopics/jacksonsink.htm
and - http://www.dep.state.fl.us/geology/geologictopics/sinkhole.htm
Lane, Ed, 1986, Karst in Florida: Florida Geological Survey Special Publication 29, 100 p.
Foundation Engineering Problems and Hazards in Karst Terranes, James P. Reger, Maryland Geological Survey, web search 06/05/2010, original source: http://www.mgs.md.gov/esic/fs/fs11.html Maryland Geological Survey, 2300 St. Paul Street, Baltimore, MD 21218
"Frost Heaving Forces in Leda Clay", Penner, E., Division of Building Research, National Research Council of Canada, Canadian Geotechnical Journal, NRC Research Press, 1970-2, Vol 7, No 1, PP 8-16, National Research Council of Canada, Accession number 1970-023601, Quoting from original source
The frost heaving forces developed under a 1 ft. (30.5 cm) diameter steel plate were measured in the field throughout one winter. The steel plate was fixed at the ground surface with a rock-anchored reaction frame. heave gauges and thermocouples were installed at various depths to determine the position and temperature of the active heaving zone. The general trend was for the surface force to increase as the winter progressed. when the frost line approached the maximum depth the force was in excess of 30,000 lb (13,608 KG). Estimates of the heaving pressure at the frost line ranged from 7 to 12 psi (0.49 to 0.84 KG/cm) square during this period. The variation of surface heaving force was closely associated with weather conditions. Warming trends resulting in a temperature increase of the frozen layer caused the forces to decline.
Leda clay slopes in the Ottawa valley are vulnerable to catastrophic landslides. More than 250 landslides, historical and ancient, large and small, have been identified within 60 km of Ottawa. Some of these landslides caused deaths, injuries, and property damage, and their impact extended far beyond the site of the original failure. In spectacular flowslides, the sediment underlying large areas of flat land adjacent to unstable slopes liquefies. The debris may flow up to several kilometres, damming rivers and causing flooding, siltation, and water-quality problems or damaging infrastructure. Geologists and geotechnical engineers can identify potential landslide areas, and appropriate land-use zoning and protective engineering works can reduce the risk to property and people.
Deposits of Leda clay, a potentially unstable material, underlie extensive areas of the Ottawa-Gatineau region. Leda clay is composed of clay- and silt-sized particles of bedrock that were finely ground by glaciers and washed into the Champlain Sea. As the particles settled through the salty water, they were attracted to one another and formed loose clusters that fell to the seafloor. The resulting sediment had a loose but strong framework that was capable of retaining a large amount of water. Following the retreat of the sea, the salts that originally contributed to the bonding of the particles were slowly removed (leached) by fresh water filtering through the ground. If sufficiently disturbed, the leached Leda clay, a weak but water-rich sediment, may liquefy and become a 'quick clay'. Trigger disturbances include river erosion, increases in pore-water pressure (especially during periods of high rainfall or rapid snowmelt), earthquakes, and human activities such as excavation
After an initial failure removes the stiffer, weathered crust, the sensitive clay liquefies and collapses, flowing away from the scar. Failures continue in a domino-like fashion, rapidly eating back into the flat land lying behind the failed slope. The flowing mud may raft intact pieces of the stiffer surface material for great distances.
Kochanov, W. E., 1999, Sinkholes in Pennsylvania: Pennsylvania
Geological Survey, 4th ser., Educational Series 11,
33 p., 3rd printing April 2005, Pennsylvania Department of Conservation and Natural Resources / Bureau of Topographic and Geologic Survey, DCNR Educational Series 11, Pennsylvania Geological Survey, Fourth Series, Harrisburg,
1999 - web search 06/05/2010, original source: http://www.dcnr.state.pa.us/topogeo/hazards/es11.pdf - Quoting from the document introduction: The first 18 pages of this booklet contain an explanation of how sinkholes
develop. In order to tell the sinkhole story, it is important to discuss
a number of related geologic disciplines. The words used to describe sinkholes
and these disciplines may be a bit unfamiliar. However, general explanations
are given throughout the booklet to help clarify their meanings.
Key words are printed in bold type for emphasis. The more important
ones are defined in a Glossary that begins on page 29.
The remaining sections, starting with “Sinkholes in the Urban Environment”
(page 18), deal with sinkholes and their impact on our environment.
This includes recognition of subsidence features and sinkhole repair.
 Sarah Cervone, [web page] data from the APIRS database, Graphics by Ann Murray, Sara Reinhart and Vic Ramey, Vic Ramey is
the editor. DEP review by Jeff Schardt and Judy Ludlow. The web page is a
collaboration of the Center for Aquatic and Invasive Plants, University of Florida, and the Bureau of Invasive
Plant Management, Florida Department of Environmental Protection contact: email@example.com [A primary resource for this article
 Center for Cave and Karst Studies or the
Center, both at
Vanity Fair - web search 06/04/2010 http://www.vanityfair.com/online/daily/2010/06/what-caused-the-guatemala-sinkhole-and-why-is-it-so-round.html
Sinkholes, Virginia Division of Mineral Resources,
Virginia Department of Mines, Minerals and Energy, www.dmme.virginia.gov Virginia Department of Mines, Minerals and Energy
Division of Mineral Resources
900 Natural Resources Drive, Suite 500
Charlottesville, VA 22903
Sales Office: (434) 951-6341 FAX : (434) 951-6365
Geologic Information: (434) 951-6342
divisionmineralresources.shtml - Web search 06/09/2010
Sink Hole & Related Engineering References
Newton, J. G., 1987, Development of sinkholes resulting from man's activities in the eastern United States: US Geological Survey Circular 968, 54 p.
Sinclair, W. C., 1982, Sinkhole development resulting from ground-water withdrawal in the Tampa Area, Florida: U.S. Geological Survey Water-Resources Investigations 81-50, 19 p.
White, W. B., 1988, Geomorphology and Hydrology of Karst Terrains: Oxford University Press, New York, 464 p.
Williams, J. H. and Vineyard, J. D., 1976, Geologic indicators of subsidence and collapse in karst terrain in Missouri: Presentation at the 55th Annual Meeting, Transportation Research Board, Washington, D.C.
Barry F. Beck, A. J. (1999). Hydrogeology and Engineering Geology of Sinkholes and Karst. Rotterdam, Netherlands: A. A. Balkema.
Beck, B. F. (2003). Sinkholes and the Engineering and Environmental Impacts of Karst. Huntsville, Alabama: The American Society of Civil Engineers.
Beck, B. F. (2005). Sinkholes and the Engineering and Envrionmental Impacts of Karst. San Antonio, Texas: The American Society of Civil Engineers.
Tony Waltham, F. B. (2005). Sinkholes and Subsidence, Karst and Cavernous Rocks in Engineering and Construction. Chichester, United Kingdom: Praxis Publishing.
Whitman D., G. T. (1999). Spatial Interrelationships Between Lake Elevations, Water Tables, and Sinkhole Occurence in Central Florida: A GIS Approach. Photogrammetric Engineering and Remote Sensing , 1169-1178.
Lincoln Log Homes Marketing, Inc., 6000 Lumber Lane, Kannapolis NC 28081 704-932-6151
Merrimac Log Homes, Henniker, NH, sells log home products, milled log home kits, log siding, and log home plans and log home construction accessories. 866-637-7462 or firstname.lastname@example.org - merrimacloghomes.com
PermaChink Systems, Knoxville TN 800-548-1231 provides a range of log chinking products, coatings, and sealants for log and other wood buildings.
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones