Pier or Pile Foundations How to Detect, Diagnose, & Evaluate Settlement, Movement, Cracks, Damage
PIER FOUNDATION PROBLEMS - CONTENTS: Structural piers or piles: how to Evaluate and Diagnose Vertical Foundation Movement and Cracks, Bends, Leans, or Shift in Piers, Piles, and Column Footings. Different causes of pier or pile foundation leaning, bulging, cracking. Pier or Pile foundation settlement, building cracks, construction on fill, clay soil troubles
POST a QUESTION or READ FAQs about diagnosing and repairing pier or pile foundation settlement, movement, cracking in continuous wall foundations and footings or in individual posts, columns, or supporting piers.
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This article discusses in detail How to Evaluate and Diagnose Movement or settlement in pier or piling foundations supporting buildings. Illustrations compare friction piers and bearing piles, types of pier/pile foundation settlement, and we discuss the role of constructing on fill or on clay soils in pier or pile performance in supporting a structure.
Pier or Pile Foundation settlement, movement, diagnosis & repair suggestions
To be used properly, this information must be combined with specific
on-site observations at the particular building in order to form a reliable opinion about the condition of that building's foundation. Anyone having
concern regarding the structural stability, safety, or damage of a building, foundation or other components, should consult a qualified expert.
Our sketch at above left provided courtesy of Carson Dunlop Associates explains the difference between bearing piles (above left), and friction piles (above right). If your home is supported by either pile type and the piles were not properly installed, you can expect differential settlement, ongoing movement, and the crack pattern you describe. Below we discuss the details of inspecting structural piers on small or residential buildings.
The concrete pier shown above is cracked and damaged, perhaps from frost. If the pier was made using steel re-bar reinforcement I don't think we face an imminent collapse of the structure above but if not, that's possible. Don't confuse a cold pour joint often visible in concrete with actual cracking or frost heave damage.
See CONCRETE COLD POUR JOINTS
Reader Question about pier settlement in a New Mexico Home
I have an adobe home built in 1995. Each adobe is 10 3/4'' wide and lying on a 24'' wide X 24'' deep foundation built on soil in New Mexico with some clay.
House dirt pad was built up on original earth and 13 cement pillars were poured along the raised portion of earth. The house is 33' X 83'. Just recently the entire north portion of the house (83') has developed a crack along the tile floor and plaster wall.
The most noticeable part of this 'shift' seems to be more toward the end of the house that sits on the pillared foundation.
The bathroom wall is about half way along this wall and the sewer line sits under this portion of the house. There is a subtle but noticeable odor in this area and the tile has separated from the wall about 1''.
What is happening and how do I fix it? The doors and windows are not opening smoothly and the wall appears to be cracking at an alarming rate. I have homeowners insurance.
Thanks, - L.C.
Reply: foundation diagnosis and repair suggestions for settling piers
A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem. For example the do-it-yourself supporting pier shown above is improper and unsafe in just about every regard.
That said, here are some things to consider:
Your observation that a settlement crack is appearing in both the "tile floor and plaster wall" indeed suggests foundation settlement.
Your comment about movement pointing "toward the end of the house that sits on the pillared foundation" combined with this being a modern home built in 1995 suggests that the home or part of it is supported by piers rather than a continuous footing.
If one or more piers is settling due to inadequate or improper construction you'd have the problem you describe.
Your observation that at least some of the supporting foundation may have been constructed on fill "House dirt pad was built up on original earth and 13 cement pillars were poured along the raised portion of earth. " is a red flag raised to question the possibility that the home was constructed on improperly or inadequately-compacted fill.
The observation that doors and windows are sticking also suggest ongoing structural settlement. I emphasize that no one can accurately diagnose a concern like this by emailed text. You need an onsite inspection by a competent expert.
The role of construction on fill and on clay soils will be critical in correctly diagnosing your building settlement, as Carson Dunlop's sketch (above) illustrates, and as we comment further just below.
I'd be a fool to pretend to diagnose building cracks by email, not to mention sight unseen.
What to Do Next About Structural Cracking and Pier Repairs
The Victoria Hotel in on Vancouver Island (photo at left) has been settling for decades, luckily rather uniformly though a closer inspection of the hotel shows masonry cracks, especially on the rear walls.
The main entry stair of the hotel today enters on what was originally the second floor of the building. The building continues in successful and safe occupancy.
#1 don't panic so much that an opportunist takes advantage of your worry to do something costly that may be unnecessary, inappropriate, ineffective .
The significance of a crack depends on many factors (described in our article below) such as length, width, pattern, location, building materials involved, position, etc. For example, a vertical 1 mm crack in drywall alone is unlikely to be enough movement to alone threaten an immediate catastrophe.
In general the level of risk of serious foundation or structural movement (and risk of costly damage or even collapse) depends on the total amount of movement that has occurred, where it is, over what time it occurred, what is the underlying cause, and what are the effects on the structure. Significant amounts of movement or things found way out of level and plumb are of course a bigger concern as are signs that movement is ongoing, increasing, or rapid.
You would do well to have someone with experience with building movement, structural questions, and foundation inspection take a look. Beware: a structural engineer who is not really familiar with foundations or residential construction may have great credentials but may give crazy and expensive advice that is safe for her but expensive for you.
So before hiring anyone ask what is their experience with building cracks and movement. You could call a home inspector who has experience, a foundation repair contractor, even a general building contractor, as a starting point. At VERTICAL MOVEMENT IN FOUNDATIONS we discuss methods for evaluating vertical foundation movement.
You might ask your insurance company to take a look, as they may do so without charging you. Of course their "expert" may not be one, and the company will certainly exclude certain types of building problems that they assert fall outside the scope of coverage of your insurance policy.
Inadequately-compacted fill construction? if this is the foundation problem cause diagnosis, which would not be a surprise given your description, the repair may require replacing or supplementing the existing piers with ones that are driven to adequate depth or are otherwise adequately supported.
Expansive clay soils? include in the diagnosis of your foundation settlement the possible role played by the clay soils in your area.
Homes built on expansive clay soils may need to include special measures to avoid seasonal or even continuous foundation movement due to moisture changes in the clay soil supporting a foundation or pier.
Supporting structural piers in coastal areas? Piers subject to tidal waters are typically constructed using driven piles as shown in our photo below. This building is located on the Maine coast.
Repairs? Typically, a building supported by piers that has one or more settling piers or columns is repaired by a combination of adding temporary support and then by replacing or repairing the settling piers or column footings, or by adding one or more additional piers designed for foundation repair.
A.B. Chance and others produce helical piers or driven friction piers. Helical piers are screwed into the soil and used to jack, level, and permanently support a settling structure. That may be a repair option your onsite expert may suggest.
The driven piles for this Maine pier are cross-braced in two directions using eyebolts and heavy chain.
Watch out: an inspector might be confused about the support beneath a home such as the one shown above.
Supported by piers a home may later have in-fill between the piers using masonry block to construct an enclosed crawl area. But these masonry blocks, if not set on suitably deep and properly-sized footing, are not supporting the structure.
Bottom line on diagnosing and repairing structural piers at a residential buildling:
If the explanation and repair advice you hear just doesn't make sense to you let me know what you were told and I can suggest some follow-up questions. And don't do anything expensive before you understand what's going on. Keep me posted on how things progress, and send along photos if you can. Such added details can help us understand what's happening and often permit some useful further comment. What we both learn may help me help someone else.
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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
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"Backfilling Basics," Buck Bartley, Journal of Light Construction, October 1994
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Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
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.
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.
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.
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.
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.
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.
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