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Construction on piers over water - pilings, moisture, movement, vapor barriers © D Friedman at InspectApedia.com Pier or Pile Foundations
How to Detect, Diagnose, & Evaluate Settlement, Movement, Cracks, Damage

  • POST a QUESTION or COMMENT 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.

Pier foundations:

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.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Pier or Pile Foundation settlement, movement, diagnosis & repair suggestions

Mud jacking founadtion repair (C) Carson Dunlop Associates

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.

Bearing strength of different soil types (C) Carson Dunlop Associates

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.

Cracked or pour joint in concrete pier © Daniel Friedman at InspectApedia.com

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

Inadequate DIY concrete block used as pier (C) InspectApedia.com Carson Dunlop Associates Toronto

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:

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

Photograph of the Empress Hotel on Victoria Island, Vancouver BC  © Daniel Friedman

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.

Helical anchor pier used to repair foundation settlement (C) Carson Dunlop Associates

Piers in tidal waters in Maine © Daniel Friedman at InspectApedia.com

Pier cross bracing in Maine © Daniel Friedman at InspectApedia.com

The driven piles for this Maine pier are cross-braced in two directions using eyebolts and heavy chain.

Long home on piers, upstate New York © Daniel Friedman at InspectApedia.com

Watch out: an inspector might be confused about the support beneath a home such as the one shown above.

Non-structural concrete block wall in-fill betweeen concrete piers © Daniel Friedman at InspectApedia.com

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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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

Question: comments on tall single-block stacked CMU piers under a deck

Too-tall concrerte block deck pier (C) Dov Ber Kahn at InspectApedia.com

I noticed the attached CMU columns for the deck, it seemed unusual and I am thinking it's not good practice.

Appreciate your assistance in clarifying this.

Also did not like the "wood boards / shims" between the columns and girder and I did note the rot of a portions of the girder. - Dov.

Dov Ber Kahn, a home inspector in Rockland County, NY has contributed photographs of various building features to InspectApedia. Mr. Kahn is a licensed home inspector in New York and New Jersey, and can be reached at Website: Kahnbhomeinspectors, Tel: 845-445-8234, Email: kdovber@googlemail.com

Moderator reply: tall single-block masonry column, unreinforced? no connection to beam? Masonry Pier Construction Codes

Great photo and question. Do you know if there is still reinforcement and concrete fill in those columns? If not they probably exceed the allowed height for masonry peers or columns.

I count eight single concrete blocks. You don't give measurements but they look like 10" tall blocks giving an 80" tall pier + footing height + another 6" or so of blocking under that birder.

I also don't see any sign of a structural connection between the top of the masonry block column and the wood beam that it supports.

Typical codes specify

Piers between 36 and 80 inches (914 and 2032 mm) in height and all corner piers greater than 24 inches (610 mm) in height shall be at least 16 inches by 16 inches (406 mm by 406 mm) consisting of interlocking masonry units and shall be fully capped with minimum 4-inch (102 mm) solid masonry units or equivalent.

or

AE603.1 General - Piers constructed as indicated in Section AE602 may have heights as follows:

Except for corner piers, piers 36 inches (914 mm) or less in height may be constructed of masonry units, placed with cores or cells vertically. Piers shall be installed with their long dimension at right angles to the main frame member they support and shall have a minimum cross-sectional area of 128 square inches (82 560 mm2).

Piers shall be capped with minimum 4-inch (102 mm) solid masonry units or equivalent.

Piers between 36 and 80 inches (914 and 2032 mm) in height and all corner piers greater than 24 inches (610 mm) in height shall be at least 16 inches by 16 inches (406 mm by 406 mm) consisting of interlocking masonry units and shall be fully capped with minimum 4-inch (102 mm) solid masonry units or equivalent.

Piers greater than 80 inches (2032 mm) in height may be constructed in accordance with the provisions of Item 2, provided the piers shall be filled solid with grout and reinforced with four continuous No. 5 bars.

One bar shall be placed in each corner cell of hollow masonry unit piers or in each corner of the grouted space of piers constructed of solid masonry units.

Cast-in-place concrete piers meeting the same size and height limitations of Items 1, 2 and 3 may be substituted for piers constructed of masonry units.

Also of interest:


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