Settlement Cracks in Slabs in Poured Concrete Slabs & Floors
SETTLEMENT CRACKS in SLABS - CONTENTS: How to Identify and Evaluate Settlement Cracks in Slabs in Poured Concrete Slabs or Floors. Concrete floor crack pattern analysis, evaluation, diagnosis, repair. Floor crack diagnosis
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Guide to concrete floor or foundation settlement cracking: this article describes How to Identify and Evaluate Settlement Cracks in Slabs in Poured Concrete Slabs or in concrete floors in basements, crawl spaces, or garages. This article series describes how to recognize and diagnose various types of foundation failure or damage, such as
foundation cracks, masonry foundation crack patterns, and moving, leaning, bulging, or bowing building foundation walls.
Types of foundation cracks, crack patterns, differences in the meaning of cracks in different foundation materials, site conditions, building history,
and other evidence of building movement and damage are described to
assist in recognizing foundation defects and to help the inspector separate cosmetic or low-risk conditions from
those likely to be important and potentially costly to repair.
Guide to Diagnosing & Fixing Settlement Cracks in Poured Concrete Slabs
Settlement cracks in a conventional concrete floor slab which has been poured inside a separate foundation wall (and often
resting at its edges on the building's foundation wall footings) are usually not connected to the foundation wall and are not supporting
any structure [except possibly Lally columns, discussed below].
[Click to enlarge any image]
So often cracks in a basement floor slab are not a threat to
Floor cracks can occasionally indicate a serious structural problem however, since there
are exceptions to what we stated just above: significant settlement of a slab which is supporting an interior load-bearing partition
or column could be a serous concern.
Settlement or movement of a slab on grade constructed building (the slab
is forming a floor in the living space) may also be a concern.
Another serious concern suggested by a floor slab crack can be inferred if if the floor cracks track to corresponding cracks in the building foundation wall. If you follow a basement or slab floor crack across the surface to the foundation
wall, and if you find a crack in the foundation wall which maps onto the wall from the end of the floor crack, there is risk
of more serious foundation damage and further investigation by an expert is warranted.
Cracks in a floor slab around a Lally column may indicate settlement
Settlement cracks in a concrete floor around a supporting Lally column might be indicative
of a serious problem such as building settlement if the columns are settling.
Independent footings may have been provided supporting
Lally columns in the building interior and those may be settling independently of the floor slab which may have been poured
around and even over them (See photo and sketch above).
In our sketch above, (I) points to a roughly circular crack forming
around the pier as the remaining slab settled away from the pier itself. [(E) is probably a shrinkage crack
occurring at a natural stress point formed by the inside corner footprint of the foundation.]
But beware, where slab thickness and local building codes allow, supporting columns may bear
directly on a poured floor slab without their own (deeper) pier or footing. In that case floor slab cracking and settling can cause
column movement and may be a structural concern.
Also watch out for columns settling down through the slab - which may show up
as sags in the floor above (supported by the column) where the slab itself may not show signs of movement.
Settlement cracks in a monolithic slab or floating slab floor may be more serious, depending on their extent since in this
case the edges and other portions of the slab are, unlike the cases above) expected to support the upper portions of the building structure.
A monolithic concrete slab is one which includes the building footing as part of the slab, created in a single continuous pour of concrete.
A floating concrete slab is one which is poured at a (generally) uniform thickness on the ground without a separate footing.
[Beware, in areas of wet soils, expansive clays, freezing climates, or unstable soils, floating slabs may be exposed to extra stresses
and may tip or crack. Proper site work and drainage are important as is proper engineering design of such structures.
Random settlement or heave cracks in garage floors
Basement and garage floor random heave and crack patterns:
Cracked and heaved concrete or settled concrete can occur in more random patterns in any concrete floor where there has been frost heaving,
soil contraction/expansion, or simple soil settlement, as shown in this photograph.
Uniform or sloping settlement in garage floors or other floor slabs
Garage or basement floor s(C) Carson Dunlop Associates"m settlement may also produce a tipped floor even if the concrete is not cracked, or the floor may
settle uniformly. Carson Dunlop's sketch shows how loose soil and gravel under a garage floor can combine with poor drainage to lead to serious slab settlement and a broken slab where no reinforcement was used in the floor slab.
If the floor slab was reinforced with steel the entire slab may pitch in the direction of settlement.
This condition occurs if the concrete was reinforced by steel or fiber cement, but was poured inside of a separate concrete
or masonry block foundation. We see this condition more often in garages in which the slab was reinforced but poured on poorly-compacted soil.
The problem may be worst if in addition to poor compaction, water runs under the slab, causing additional or more rapid soil settlement.
Carson Dunlop's sketch shown here depicts slab bending, cracking and failure at opposing foundation walls due to construction on partially-disturbed soil independent of a drainage problem.
My first construction job (for pay - DF) was to rake level the backfill soil that the contractor had dumped inside of the newly-completed
garage foundation in a series of homes.
No compaction of any kind was performed. When a lot of fill, several feet or more in depth,
was required to bring the slab to the desired height, there was a good chance that the slab would settle or tip in the future.
Garage slabs which were poured inside of the foundation walls but which were pinned to the foundation sides (typically using
re-bar set into holes punched into the masonry block foundation), the slab was resistant to settlement or movement even if there
was modest soil settlement below.
In a garage where the slab has settled you can often spot the original level of the slab and thus can measure the amount of settlement. Look for
a concrete line above the level of the top of the slab and found along the masonry block or poured concrete foundation
wall. we have seen this line ranging from a fraction of an inch to six to eight inches above the current level of the slab!
Evaluating Garage Floor Slab Settlement
Question: how to separate slab settlement from foundation damage
(Aug 27, 2016) Jen said:
Thank you for this informative article! My Husband and I just bought a house in Grand Island, NY 4 weeks ago. It's a 3,000 Sq ft 2 story colonial, full basement. We noticed sloping settlement around the perimeter of our entire basement. 2-4 feet parallel to each wall, the cracks are about 1/4" wide. We recently had a radon test done, normal results and no water seepage. Our basement is very humid and moist so we just purchased a dehumidifier for it.
To make a long story short, I've been obsessively reading articles about basement slab cracks and have been measuring everything with a level. I'm terrorified that we purchased a lemon. Can you give me any advice? Our climate here ranges from 90° in the summer to -10° in the winter and we have tons of clay in our soil. Any feedback would be greatly appreciate!
From just your e-text I can't guess at the cause nor the total effect of the cracks you describe. If the "cracks" are dead straight and parallel to building walls they might be deliberate control joints.
If the cracks do not extend up into foundation walls, that is if the house foundation is plumb, level, and not cracked, then the problems in the slab may still need to be addressed but we're missing evidence that the structure itself is being affected.
If the slab and house are brand new, moisture may still be coming off of concrete and other building products.
Question: how do I get an assessment of & recommendations about settlement in our Denver area garage floor slab?
2016/11/16 Kelly Dreilich said:
Our house underwent an inspection and the inspector noticed that the southwest corner of our garage slab has settled 3 in, Red line is apparent. The corner represents foundation to the outside wall to the left and the foundation to the entry to the house from the garage. There are not any cracks, pulling away, separation of any kind on the inside of the garage, outside on the brick wall, foundation etc. No cracks in dry wall both inside the garage and house. The house is a 13 year old custom home in colorado, just south of Denver.
Since that is the most inside part of the garage where there is never any water accumulation ever, and we never get any water in the garage at all. The buyers want someone to come out to inspect the slab and make recommendations. They are fearful that the foundation could be compromised in the the future.
We are the orginal owners and I have noticed that red line since we moved in and the house sat for one year before we purchased it and our inspector did not catch it. But I want to know who is the best and most qualified person to come and inspect this part of the garage, a structural/foundation company or a mudjacking company? I want to at least get two assesements to compare evals. Any advise or recomendations would be appreciated. Kelly my email is email@example.com and cell phone is 3039139903
Reply: how to find the cause of slab settlement, look for expansive clay soil or unstable soil, assess impact, plan repair
Sorry, Kelly but I don't know what "red line is apparent" means. If you mean that a slab settled 3", leaving a visible mark along the garage wall, then I agree that is a significant settlement.
Without on-site expert work, we don't know if your slab settlement is due to construction errors (such as building a slab on poorly-compacted fill) or if unstable soil below the slab is a factor. In Colorado the Front Range area is at particular risk of expansive clay soil damage though expansive clay soil problems are found elsewhere in the state too.
See FOUNDATION FAILURES in CLAY SOIL for an explanation of foundation or slab damage due to expansive clay.
Readers living in other ares where there is construction on shale should also see FOUNDATION DAMAGE by MATERIAL or INCLUSIONS - heaving damage to foundation walls & cracking foundations or slabs due to Iron sulfide mineral (pyrrhotite) inclusions in concrete or due to building on Iron sulfide mineral (pyrrhotite) shale.
You're right to consider the effects of water, a factor that affects expansive clays as well as under-slab fill settlement in general. Though you don't see water inside the garage where the slab settled, there could still be an outside water cause or factor if surface or roof runoff are draining towards the building.
The question raised by your buyers is a reasonable one, though I doubt that anybody with any sense is going to give an absolute guarantee about the future conditions in your home. A reasonable approach is to follow something like these six steps to slab settlement evaluation and repair planning:
Assess impact on structure: Assess the current extent of impact on structure. Is there movement of or damage to the foundation walls themselves? Often, infact usually a slab is structurally independent of the supporting foundation wall and footings.
Assess Safety: Look for trip hazards in the garage: broken uneven slab with more than 1/8" difference across a crack. Other safety hazards can occur, such as damaged gas piping (fire and explosion risk) when a building suffers significant movement or dislocation.
Find causes of settlement: Consider the most-likely causes of the movement as those will inform what repair is needed as well as the urgency of repair
Consider history of settlement: Consider the probable history of the movement: is it original, occurring gradually over 13 years, or sudden and recent? The implications for diagnosis and repair would be different as would expectations of further movement. Not every settled garage slab is dangerous nor needs repair.
Decide on justification for invasive inspections or tests: Decide whether or not the visual inspection, history, knowledge of local soil conditions and site factors does or does not justify the cost and trouble of further, more invasive investigation such asl borings outside or soil borings through the garage slab inside
Make repair recommendations: Recommend watch and wait or repair, and if repair, recommend reasonable repair methods. Often slab jacking (pumping grout under a slab) and water runoff control are all that's needed but if your expert finds that there is a more serious site issue then other steps could be needed.
Before you do something expensive you're welcome to use the page top or bottom CONTACT link to send me your inspectors reports and photos for comment. I can't be as smart as an onsite expert but I might have some suggestions.
An experienced contractor, mason, foundation repair company may be quite sufficient for this investigation. Often those workers have seen hundreds or thousands of similar situations and have thus useful field experience.
Some home inspectors in your area may also have specific expertise with foundation damage and expansive clay soils. Carl Brahe is a Denver CO area home inspector who has written about expansive clays in Colorado. Tel: 303 816-5556. (We have no personal, business, nor any other economic relationship with Mr. Brahe nor with other consultants, products, or services discussed here at InspectApedia.com)
A civil or structural engineer would be useful if she or he has specific expertise and experience in residential construction and foundation diagnosis and repair work. If the problem found is traced to significant building structural damage or need for costly structural repair, I would certainly like the opinion of an independent design professional. Beware of conflicts of interest and loud arm-waving with no credible supporting observations and explanations of the situation.
If you or other readers face very costly repairs traced to unstable clay soils you might want to consider contacting one of the national experts such as Fredlund who has been writing about this issue for decades.
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.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
John Cranor is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-747-7747 or by Email: firstname.lastname@example.org
"Concrete Slab Finishes and the Use of the F-number System", Matthew Stuart, P.E., S.E., F.ASCE, online course at www.pdhonline.org/courses/s130/s130.htm
"Best Practices for Concrete Sidewalk Construction," Balvant rajani, Canadian National Research Council
"Design Considerations for Perlite Roof Slabs," a chapter in "Perlite Concrete Grade for Lightweight Concrete Construction", United Perlite Corporation
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.
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.
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.
Sinkholes in Guatemala, Guatemala City, Wikipedia - web search 06/04/2010 - http://en.wikipedia.org/wiki/Guatemala_City
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: firstname.lastname@example.org. 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.
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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.
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