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Repair Methods for Foundation Settlement or Vertical Foundation Movement

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Repairs for vertical foundation movement, damage, cracking:

This foundation repair article discusses how to repair vertical foundation movement or foundation settlement using methods to stabilize or even level and straightened a settling or moving foundation wall or floor slab, by using slab jacking, driven steel pins, helical or "screw piers", friction piers or piles or even foundation reconstruction.

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Repair Methods for Vertical Foundation Movement - Foundations, slabs, fireplaces, chimneys

Photograph of a substantial settlement crack in poured concrete.

In the photos shown here, substantive cracks appeared and continued to increase in size in this poured concrete foundation used to support a modular home which had recently been completed.

../structure/Photograph of a substantial settlement crack in poured concrete.

The cracks and foundation movement were probably due to a combination of: poorly prepared foundation footings, blasting on an adjacent building lot to prepare that site for new construction, and possibly omission of steel reinforcement in the poured wall.

As movement appeared to be ongoing over more than a year, the builder might have repaired the foundation by supporting it from below using one of the methods listed here.

Foundation Repair Using Mud Jacking, Pressure Jacking, Slab jacking Methods

Mud jacking founadtion repair (C) Carson Dunlop Associates

Grout pumping or mud jacking is used to stabilize soils below settling footings or slabs.

The mud jacking or grout pumping method of foundation repair is capable of lifting a slab and possibly some structures.

Mud jacking is suitable if bearing rock or stable soils are not too deep.

For cases where bedrock or suitable stable soils are deeper, slab-jacking methods are usually preferred - see the next foundation repair item just below.

Slab jacking (sketch below) is used to stabilize or lift and level settling concrete slabs, including interior floor slabs poured within the perimeter of a building foundation, and also lifting and leveling of monolithic concrete slabs or slab-on-grade construction.

Photograph of slab jacking.

If a floor slab or slab on grade construction is tipped, settling, or cracking, the underlying cause may vary among poor site preparation such as pouring over un-compacted fill, poor surface water runoff control resulting in soil loss or compaction, expansive clay soils, soil subsidence over buried debris, and sinkholes. [Sketch above provided courtesy of Magnum Piering, Florida.]

Contact information for Magnum Piering is atReferences or Citations .

[Click to enlarge any image]

Mud jacking schematic (C) Carson Dunlop Associates

Sketch of mud jacking or pressure grouting to lift and repair a concrete floor slab

Carson Dunlop Associates' sketch above shows how slab jacking or mud jacking, also called pressure-grouting, might be used to repair a settling garage floor slab.

Foundation Repair Using Driven Steel Pins

Photograph of Magnum steel pier foundation leveling or jacking.

Driven steel pins

are used to stabilize settling foundation walls or footings. A pin is driven next to the foundation and is inserted into the soil until it contacts bedrock. Variations in name and type for these steel foundation repair pins or piers include push piers, steel push piers, helical piers, and push pins.

The driven pin foundation repair method, like the alternative piers listed below, is often used when a portion of a foundation wall is moving or settling, perhaps because of improper site work or footing undermining.

The cost of this method is about $1200. to $1500. per pin for average 30 ft. depth.

The steel pin foundation repair method permits more precise leveling control across the building than grout pumping.

Some reviewers expressed a concern about a possible durability problem? The manufacturers typically warrant the product for 60 years.

[Sketch at left was provided courtesy of Dwyer, Magnum Piering, Florida, via ASHI Seminar 1998, edited by DF.]

Contact information for Magnum Piering is included atReferences or Citations .

Helical Pier or Screw-Pier foundation Repair for Settled Footings, Slabs, or Walls

A.B. Chance helical screw piers are an approach similar to the above, but may be shorter in length and useful where soil conditions do not provide shallow bedrock or won't work well with friction piers (below).

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

Helical piers to repair sinking foundations are often used in building repair or reconstruction, and include models which can be used to level floor slabs as well.

Sketch above provided courtesy of Carson Dunlop Associates [Toronto]. Contact information for A.B. Chance is detailed atReferences or Citations .

Friction-Pie, Driven Pie, Push Pier Foundation Repair for Settled Footings, Slabs, or Walls

Friction pier or pile for foundation repair (C) Carson Dunlop Associates


Rod & Steel U-Channel or I-Beam Foundation Repair for Settled Footings, Slabs, or Walls

Rod and steel channel structural repair over bad soils (C) Carson Dunlop Associates

Rod & Channel Repair

 to Stabilize Structures over Poor Soils. Carson Dunlop Associates' sketch of steel rods and "U" channels illustrates how an engineer may specify a repair to stabilize a building which has been constructed over un-stable soils.

Rod and u-channel structural repairs are more likely to be used where soil conditions prohibit the other pier or jacking methods illustrated above.

Threaded steel rods are run through the width or length of the damaged structure and bolted to vertical steel U-channels on the building exterior.

You may see a similar use of through-building threaded steel rods in 19th century masonry buildings in an attempt to stabilize structural masonry walls.

Instead of "U" channels the rod ends are mounted through steel plates, often in a decorative shape.

Foundation Repair of Settled Footings, Slabs, or Walls by Reconstruction

Reconstruction of foundations:

Some engineers who examine a failing foundation may prescribe excavation and reconstruction, possibly with reinforcement over the original design and with additional foundation and site drainage.

And indeed in some cases these extensive foundation repair steps are completely appropriate and necessary both to repair the building and to prevent a recurrence of the trouble.

Watch out: We saw this method used for a home in Hyde Park, New York when it was discovered that the home had been built half over a landfill and was suffering from substantial differential settlement.

Helical screw piers or even driven steel pins might have worked at about one tenth the cost of the project as it was designed. We don't know if that alternative was considered.

See FOUNDATION CONTRACTORS, ENGINEERS for advice on how to choose an expert to diagnose or repair a building foundation problem.

Foundation Repair Pier Sources

ECP helical piers are ideal for applications where there is a need to resist a tension or compressive force or both. When combined with an ECP helical bracket, these helical screw anchors are ideal for foundation repair applications.

ECP helical piers have been used in many utility and civil construction projects over the years, from guy wire applications to underpinning and soil nail applications, upon installation helical piers load tested to prove their capacities. Earth Contact Products recommends that only a registered engineer design and oversee the design and application of helical piers when used in foundation repair or new construction projects.

Remember, not all helical piers are equal. On your next project make the ECP helical pier your foundation repair solution of choice. Many times helical piers and helical anchors are the best solution for your foundation project due to one of the following factors:

- retrieved 1/29/2014 original source: http://www.earthcontactproducts.com/HELICAL_PIER.asp

 




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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

On 2021-03-23 by (mod) - danger of cracked plaster interiors as house settles in after being jacked, lifted, straightened

@gamelyells,

I can tell you from both study and direct personal experience that jacking up a house is tricky and dangerous.

Generally the procedure is done by experienced people and they lift the house as uniformly as possible and very slowly.

The house is set back after repairs to its structure and foundation - also uniformly and slowly. Even so there may be subsequent interior cracking and damage. For some house jacking it's necessary to add diagonal bracing in the building interior before it is moved.

The first priority is safety for yourself and other workers. That means using an adequate number of jacking points and strong lifting timbers. It also means working slowly.

In your particular case there's no point in even doing this work if you're not prepared to construct adequate footings and foundation walls so that when the house is set down it is on a stable foundation.

In 1956 my family lifted an antique house in Goochland County Virginia (Lanyfair, re-named Vinita Farms, later St. John Vianney Seminary, later abandoned - see my sister's photo from 2007, below) and then set it back on its foundation after repairs. The first floor had sloped 18" across a six-foot pantry between dining room and kitchen.

With the house now leveled and secure, mom had all of the interior wall plaster-lath repaired and painted. The next year as the house "settled-in" to its new position large diagonal cracks appeared on many interior walls. Mom was so discouraged (and out of money) that instead of repairing the plaster all over again, she covered all of the walls with thick wallpaper or in the worst-damaged-rooms, with burlap fabric wallpaper.

Vinita Farms Goochland County outside Richmond Virginia (C) Daniel Friedman at InspectApedia.com - St. John Vianny seminary

Below is the house entry hall at my parent's house in 1957. Mom is at lower right in the photo. (Religious celebration, age 13).

The settlement cracks were hidden by wallpaper, and the house stabilized in its new position without further movement.

Plaster cracks covered by wallpaper after house jacking (C) Daniel Friedman Vinita Farms at InspectApedia.com

See also PLASTER REPAIR METHODS

On 2021-03-23 by gamelyells

Hello, let me thank you for this website. The information found on this site has been invaluable to me for several years and I appreciate the knowledge and helpfulness of it. Thank you.
Ok, I need to level my mothers house.

It doesn’t necessarily have to be level but level would be cool. The house is around 115 years old and was moved to its current location about 3 decades ago. I’m in East Texas over sugar sand and clay soils. There is major subsidence still happening.

Looking under the house several joists are rotted and there are gaps between the cinder blocks it sits on and the sill beams of the house. For several years apparently the kitchen sink just drained under the house.

I've got it dried out under there but it is nasty. I plan on taking pressure off of the joist with a large beam and a bottle jack and then sister-in-law the rotted joists, then placing cinder blocks back under the sill beam and letting it back down.

This is going on all over the house. I guess, my question is in what order do I need to lift the house? Does it have to be lifted all at once? Can I do a side at a time? Is it better to use a jack at each end of the beam or can I use one in The middle?

I am aware that I should consult with a professional. There is no money to pay anybody anything with. I feel this recent shifting is due to the recent winter snow we just had here in Texas but we were denied by fema. I have to do something and it has to be now.

This house is all we have and no, we dont have insurance. Any advice any one can give on my situation is desperately needed and much appreciated. Thank you.

On 2021-03-21 - by (mod) -

@Mark J,

That's helpful; so most-likely there is some settlement on the left or right (or both) of the point at the bottom of that crack

OR some frost heave at a point right below the crack.

Frost heave is more likely if the footing may not extend below the frost line;

Settlement may be ongoing or related to water spilling close to the foundation wall.

As the crack has been "repaired" (filled-in) and re-appeared we'd guess that either the repair wasn't up to handling the temperature changes in the wall or there is cyclical or ongoing movement;

The width of the crack in the repair material is what, about 1/16" - not major;

The width of the original crack looks like about 1/8" in your photo - vertical cracks of that size would not usually, by themselves, lead to a sudden catastrophic collapse of the wall.

On 2021-03-21 by Mark J

Showing a bit more context

On 2021-03-21 - by (mod) -

@Mark J, That photo is a good starting detail but I need to see context: outside and inside from more distance so as to have a clue about what's going on.

On 2021-03-21 by Mark J

A previous owner repaired this large crack that has reappeared. A curved window and ledge are directly above this image.

This crack has re-emerged. over the last 10-yrs. I think it was chiseled out in a v-shape in the previous repair. The house in Chicago was built in 1927. On the outside is what was a very large shrub (American Yew) that was trimmed way back 15 years ago that may be exerting pressure on the wall. No water comes in. Clearly wider at the top than the bottom—due to settling to the right or left? What advice do you have?

On 2017-12-11 by Anonymous

I found cracks after i built first floor witout pillers

On 2017-02-08 by Anonymous

Bowed basement wall moving lower brakes

On 2015-01-13 - by (mod) -

Anon I would not pretend to perform engineering analysis, much less by e-note for an unknown property. You need an on-site expert. It's possible that jacking and helical piers can be used - depending on what your engineer finds workable.

On 2015-01-12 by Anonymous

originally the foundations for a property were piled using piled system which supported a ground beam on which the property was built these have failed and remedial work is now required, a site investigation has revealed the original piles are between 14 to 16 meters and need to be replaced with 20 meter piles. What is the best way to go about this thank you

On 2014-09-25 - by (mod) -

Don

I would not attempt a repair without first obtaining a solid diagnosis of the cause of the trouble, since the cause may dictate the repair. Meanwhile watch out for unsafe conditions such as leaky gas lines or damaged wiring or plumbing.

On 2014-09-25 by Don

I have a building that is a slab on grade and it has settled 6" on one side. What is the best way to raise and support the foundation doing the work myself?

On 2014-08-23 - by (mod) -

Megha I'd like to help but with no actual information about the structure, crack, load, function of the beam or anything else, any comment would be wild speculation.

On 2014-08-23 by Megha

I have noticed a crack of laminated beam in basement which would impact the load bearing capacity, How intense is this problem and what would be the measures I might need to take to fix it? Could any one post there recommendations.

On 2013-03-03 by Lara

My home was built in the 1960s and the foundation was repaired at the exterior with pins before I purchased it. At this time, the floor at the exterior walls is approximately 2 inches higher than the floor at the center of the house. There are small cracks in the walls throughout the house which come and go over time. The brick exterior has some large-ish stair step cracks and one quarter inch vertical crack through bricks, but it is not clear which of these were present before the repair, were caused by it, or if they have worsened since.

The general thinking is that the foundation repair over corrected and jacked the exterior walls up too high. My question is: when should I get concerned that the structural integrity has been compromised to the point it may collapse inward or some other terrible event? Or is the center sag not too worrisome?



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