Case studies: every question answered
150 questions with short answers. Each links to the full, sourced explanation.
How deep did steel piers go across a large Tulsa apartment complex?
Across 396 logged piers at a 34-building Tulsa complex, refusal depth ranged 2 to 40 ft, median 12 ft, at a median 9,000 psi driving pressure.
- Tulsa apartment pier depths: What did the buildings show?
- The engineer's drawings marked pier locations and foam-injection areas building by building, but did not include a written narrative, soil borings or a stated cause.
- Tulsa apartment pier depths: What did the engineer find was causing it?
- No cause was written up. Standard notes on every sheet called for gutters on all eaves and stated that better drainage around each building would improve structural stability.
- Tulsa apartment pier depths: What repair was specified?
- 469 galvanized steel push piers at exterior footings, hydraulically driven to refusal at bedrock; plan spacing typically 3 to 5 ft, with some 6 to 7 ft spans.
- Tulsa apartment pier depths: What happened on the job?
- Work ran in five phases from September 2025 into 2026. Of 469 planned piers, 396 have both a logged depth and pressure. Buildings that first needed siding or wall demolition for access are the ones with missing logs.
- Tulsa apartment pier depths: What does this case show about Oklahoma foundations?
- Depth to a pier-stopping layer is not uniform even within one property.
- Did piers on the same site reach refusal at the same depth?
- No. Logged depths ran from 2 ft to 40 ft. Phase medians ranged from 10 to 20 ft, and one building's piers ranged from 7 to 40 ft.
- Did deeper piers take more pressure?
- Hardly. Across 396 piers the correlation between depth and logged pressure was about r = -0.06; pressure tracked work phase more than depth.
- Tulsa apartment pier depths: What did the engineer point to as the cause?
- No written cause was given, but every drawing called for gutters and better drainage, and one building near a retaining wall was described as subsiding from bad site drainage and uncontrolled roof water.
How did downspouts help crack the foundation of a 2007 Bristow house?
Downspouts discharging at the foundation eroded two corners. The engineer called it a defect and specified piers, slab leveling and downspout extensions.
- Bristow downspout erosion: What did the house show?
- The engineer inspected the house in February 2026. It is a one-story timber-frame house with vinyl siding, built about 2007, on a slab-on-grade with continuous perimeter footings and stem walls.
- Bristow downspout erosion: What did the engineer find was causing it?
- The engineer named two factors:
- Bristow downspout erosion: What repair was specified?
- Piers under the continuous footings at the locations on the engineer's drawing; Polyurethane slab leveling at marked areas, to "stabilize and partially lift"; A leak test of the sub-slab supply and drain lines.
- Bristow downspout erosion: What happened on the job?
- The record shows that an updated estimate based on the engineer's recommendations was prepared in March 2026. It does not record whether the work was done.
- Bristow downspout erosion: What does this case show about Oklahoma foundations?
- Downspouts are a concentrated water source. ASCE's homeowner guide for shrink-swell soils recommends downspouts that discharge at least 3 feet from the foundation into well-drained areas.
- Is a downspout that drains at the foundation a defect?
- In this report the engineer called downspouts discharging at the foundation a defect and called for extensions at every downspout so water flows away from the house.
- Bristow downspout erosion: Can a house less than 20 years old need piers?
- Yes. This house was built about 2007 and in 2026 had significant stem-wall cracks on the eastern part of the house; the engineer specified piers under the continuous footings.
- Bristow downspout erosion: What does 'stabilize and partially lift' mean for a slab?
- It was the engineer's stated goal for the polyurethane slab leveling: stop the movement and recover some, not necessarily all, of the slab's lost elevation.
What did an engineer specify for a previously piered Sand Springs house?
21 perimeter steel piers at least 10 ft below the footing, 10 to 15 interior helical piers with foam, and a duct camera check, for active clay and additions.
- Sand Springs re-piering scope: What did the house show?
- The engineer inspected the house in May 2025. It is a two-story wood-frame house with brick veneer. The garage is an addition, and a former garage was converted to living space. The foundation is a slab-on-grade with continuous perimeter footings and a floating floor slab.
- Sand Springs re-piering scope: What did the engineer find was causing it?
- The engineer named three factors:
- Sand Springs re-piering scope: What repair was specified?
- Perimeter (item 1). 21 perimeter piers, shown at 9 ft dimensions on the plan, with equal spacing where none is given. The engineer's pier specification requires:
- Sand Springs re-piering scope: What does this case show about Oklahoma foundations?
- Shale is both the problem and the target. A federal survey of expansive materials identifies clay-rich sediments and shales as the most troublesome expansive materials.
- Sand Springs re-piering scope: What is a pier log?
- A record the engineer required for every pier: depth, pier type, diameter, driving pressure and amount of lift.
- Sand Springs re-piering scope: Why are additions expected to move separately?
- The engineer noted that the garage and converted room were additions, so independent movement at the joints with the original house is expected.
- Sand Springs re-piering scope: Why use helical piers inside and steel piers outside?
- The engineer specified steel push piers under the perimeter footings and helical piers under interior load-bearing walls, with foam injection elsewhere under the slab.
What did an engineer specify for a south Tulsa slab with failing walls?
4 perimeter steel piers, 10 to 15 interior helical piers with foam, crack stitching, new retaining walls and channel drains, for active clay movement.
- South Tulsa slab and walls: What did the house show?
- The engineer inspected the house in January 2026. It is a two-story wood-frame house with brick veneer, an attached two-car garage and a partly converted attic. The lot has a pool and retaining walls.
- South Tulsa slab and walls: What did the engineer find was causing it?
- The engineer named shrink-swell of active clay under the perimeter and slab, and ineffective surface drainage at the back of the house.
- South Tulsa slab and walls: What repair was specified?
- Perimeter piers. 4 perimeter steel piers at spacings of 2 to 7 ft shown on the plan. They must penetrate at least 10 ft below the bottom of the foundation into firm, stable strata, and be driven to refusal on bedrock (blue shale) per the detail.
- South Tulsa slab and walls: What does this case show about Oklahoma foundations?
- Ponding near a slab matters on clay. ASCE's homeowner guide for shrink-swell soils warns that ponding water near a foundation can cause localized heave. It recommends checking grading and drainage every year.
- South Tulsa slab and walls: When does an engineer accept foam instead of interior piers?
- Here foam injection was acceptable under the slab only if warranted against all slab movement. The engineer noted that foam rests on the existing soil, not on bedrock.
- South Tulsa slab and walls: Are uneven upstairs floors always a foundation problem?
- No. In this house the engineer attributed uneven upstairs floors over the garage to sagging floor framing and specified framing repair, not piers.
- South Tulsa slab and walls: Why replace pool channel drains as part of a foundation repair?
- The existing channel drains were damaged and painted over, and water was pooling on the patio. The engineer called for 4 in. channel drains placed to stop the pooling.
What did an engineer specify for an 80-year-old Tulsa basement house?
15 exterior steel piers, a rebuilt stairwell wall, new beams and posts, porch foam and a new sump pump, for age-related settlement and basement water.
- What did the house show?
- The engineer inspected the house in January 2014. It is a two-level timber house with brick veneer and a basement. The stem walls are clay vitreous tile, the basement walls are brick masonry on spread footings, and the floor is framed with 2x10 joists at 16 in. on center.
- Older Tulsa basement house: What did the engineer find was causing it?
- The engineer described the movement as age-related settlement plus long-term deflection of the timber framing, typical of a house of this age. Poor maintenance and basement water added to it.
- Older Tulsa basement house: What repair was specified?
- The report was a ten-item scope:
- Older Tulsa basement house: What does this case show about Oklahoma foundations?
- Old houses need the footing checked before piering. Clay tile stem walls are an older construction type. The engineer made verifying the footing part of the pier scope and noted that a supplemental footing may be required; Basement water is part of the structural picture.
- Older Tulsa basement house: Why might an engineer say a supplemental footing could be needed before piering?
- This house had clay vitreous tile stem walls. The engineer asked that the foundation construction be verified before piering and noted that a supplemental footing may be required, because a pier can only lift what sits on a sound footing.
- Older Tulsa basement house: Can new beams fully remove old floor sag?
- Not always. Here the engineer specified LVL beams on new posts but expected only partial recovery of the long-term deflection in the floor framing.
- What did the engineer do about water in the basement?
- The sump pump was dead and there was seepage at the walls and floor. The engineer called for a new sump pump, hydraulic cement on the basement walls, and epoxy floor paint.
What did an engineer specify when old piers stopped holding in south Tulsa?
Cracks reopened along a previously piered garage wall; the engineer said to repressurize those piers or replace them, add 3 new piers, and level the slab.
- South Tulsa old piers repressurized: What did the house show?
- Stone veneer separations at the southeast corners of both the house and the garage; Hairline to 1/8 in. cracks on the south, east and west walls and on the chimney; Hairline to 1/4 in. interior cracks throughout, and floor cracks in the entry, kitchen, living room and hall bath.
- South Tulsa old piers repressurized: What did the engineer find was causing it?
- Shrink-swell movement of active clay soil, together with loss of support from the existing piers along the garage's south wall, which were no longer holding.
- South Tulsa old piers repressurized: What repair was specified?
- 3 new piers at the southeast corner, shown at about 3 ft spacing near the corner, at least 10 ft below the bottom of the foundation; Repressurize the existing piers on the garage's south wall (about 9 ft spacing on the plan); if they would not repressurize, replace them with new piers; For the slab, steel slab piers about 6 ft on center, or foam injection on about a 6 ft grid with a warranty, or a combination, after consulting the engineer.
- South Tulsa old piers repressurized: What happened on the job?
- The record shows the repair contractor's proposal was checked against the engineer's requirements, a plumbing leak test was provided, and an updated scope was sent in early 2026.
- South Tulsa old piers repressurized: What does this case show about Oklahoma foundations?
- This house had already been piered, yet it was moving again. The old piers were along one garage wall, and the new distress appeared at an unpiered corner, in reopened cracks along the old pier line, and in the interior slab.
- Do old piers always have to be replaced?
- Not in this case. The engineer's first step was to repressurize the existing garage wall piers, and to replace them with new piers only if they would not repressurize.
- South Tulsa old piers repressurized: What options did the engineer give for the slab?
- Steel slab piers about 6 ft on center, foam injection on about a 6 ft grid with a warranty, or a combination, with the engineer consulted first.
- South Tulsa old piers repressurized: When should the plumbing be tested?
- The engineer called for a plumbing test both before and after the repair.
Why did a 1928 Tulsa basement wall need a full rebuild?
Years of lateral soil and water pressure bowed the lower block wall inward, so the engineer ruled out crack repair or bracing and called for a rebuild.
- Tulsa basement wall rebuild: What did the house show?
- The house is a one-story wood-frame house without veneer, built about 1928. It has a crawl space under most of it and a partial concrete-block (CMU) basement at the west end, all on a continuous trench footing. The same engineer had inspected it since 2009.
- Tulsa basement wall rebuild: What did the engineer find was causing it?
- The engineer concluded the wall had failed gradually over years under long-term lateral soil pressure and hydrostatic (water) loading. The soil was presumed to be silty clay with trace sand and moderate expansive potential.
- Tulsa basement wall rebuild: What repair was specified?
- The engineer stated that crack repair or more bracing would not be adequate. The scope was:
- Tulsa basement wall rebuild: What does this case show about Oklahoma foundations?
- Water behind a wall adds load. Building-science guidance for basements calls for a perimeter drain outside the foundation wrapped in geotextile and free-draining backfill or a drainage board to carry groundwater down to it.
- Why wasn't bracing enough for this basement wall?
- The engineer found the lower part of the wall leaning and bulging inward, worse than at a 2017 inspection. The engineer stated that crack repair or added bracing would not be adequate and called for full reconstruction.
- Why didn't the existing steel columns hold the wall?
- They were only bolted to the masonry and had no independent footing, so they moved with the wall instead of restraining it. The engineer called for them to be removed and said any new bracing must be independently supported and engineered.
- Tulsa basement wall rebuild: Why does silt end up in the sump?
- Stormwater and soil were entering at the base of the failing wall. The silt ran to the sump and clogged the pump.
Why did a 1953 Tulsa crawl space home need drainage work along with piers?
Surface water was entering the crawl space and old concrete piers at one corner had stopped holding; the engineer specified steel piers plus drainage fixes.
- Tulsa crawl space water and piers: What did the house show?
- Wood floors slightly uneven, which the engineer considered normal long-term framing sag for the home's age; Concrete piers previously installed at the southeast corner; In the southeast bedroom, cracks and a warped wall under the east window caused by window leaks, and a corner separation at the south window from wall movement.
- Tulsa crawl space water and piers: What did the engineer find was causing it?
- Surface water was the main cause: the at-grade crawl vent, planters holding water against the walls, downspouts at the foundation and a flat front yard.
- Tulsa crawl space water and piers: What repair was specified?
- Install new steel piers at the southeast corner, replacing the old concrete piers, as the repair contractor had proposed; Build a masonry curb around the north crawl vent; Grade the north planter down toward the north and remove the east planter.
- Tulsa crawl space water and piers: What does this case show about Oklahoma foundations?
- Most of this engineer's list was water control, not structure.
- Tulsa crawl space water and piers: Why did the engineer say to remove the vapor barrier?
- The soil under the existing barrier was damp, and the engineer wanted the crawl space soil to be able to dry once water entry was stopped.
- What was wrong with the old piers?
- Concrete piers previously installed at the southeast corner were no longer holding. The engineer endorsed replacing them with new steel piers.
- Tulsa crawl space water and piers: Were all the wall cracks caused by the foundation?
- No. Cracking and a warped wall under one bedroom window were traced to a leaking window, which the engineer said to seal.
Why did a 1970 Claremore slab house on a sloped lot crack everywhere?
The engineer blamed changing moisture in the clay under the footings and slab, and specified perimeter piers, polyurethane slab leveling and a leak test.
- Claremore sloped-lot slab: What did the house show?
- The engineer inspected the house in December 2025. It is a one-story timber-frame house with brick veneer and fiber siding, built about 1970. The garage had been converted to living space and a patio addition abuts the original east wall.
- Claremore sloped-lot slab: What did the engineer find was causing it?
- The engineer attributed the movement to "variations in the moisture content of the soil beneath the footings and slab," describing the soil at foundation level as a mildly active clay. The report also noted the steep slope and the additions, but did not name them as the cause.
- Claremore sloped-lot slab: What repair was specified?
- Piers under the continuous footings at locations shown on the engineer's drawing; Polyurethane slab leveling where the slab is out of level. The exact areas are to be set by the contractor from a floor survey.
- Claremore sloped-lot slab: What does this case show about Oklahoma foundations?
- Clay subsoils formed from shale are common here. The USDA describes the Dennis series, whose type location is in Rogers County, as formed in residuum weathered from Pennsylvanian shale.
- Why test the plumbing before lifting a slab?
- Leaking supply or drain lines add water to the soil under a slab. The engineer called for a licensed plumber to leak-test supply and drain lines and repair any leaks as part of the scope, and cautioned against lifting large areas over plumbing.
- How were slab cracks to be repaired after leveling?
- By stitching with carbon fiber strips and self-leveling epoxy. If a height difference remained across a crack, the engineer called for saw-cutting at least 6 in. each side and re-pouring.
- Claremore sloped-lot slab: Is some movement after piering normal?
- The engineer wrote that some minor movement after piers are installed is quite common, and advised waiting several weeks after stabilization before cosmetic repairs.
Why did a Bartlesville commercial building need piers and floor leveling?
Its perimeter had settled while the interior slab heaved; the engineer specified 13 steel piers to shale or rock, then interior leveling, plus gutters.
- Bartlesville heave and settlement: What did the house show?
- Interior floors out of level, sloping from 1/4 in. to 3 in.; doors had been trimmed to fit; On the east unit, cracks of 1/4 to 1 in. and displaced concrete blocks on the south, east and west walls, with soffit trim separations at the southeast and southwest corners; Incomplete, rusted guttering, with downspouts discharging directly against the foundation; spalled curbs and an aged roof.
- Bartlesville heave and settlement: What did the engineer find was causing it?
- The engineer separated two mechanisms. The perimeter of the east unit had settled on its south, east and west sides.
- Bartlesville heave and settlement: What repair was specified?
- 13 steel piers on the south, east and west sides of the east unit, per the engineer's sketch. Caulking between veneer and windows was to be removed before lifting; Piers driven deep enough to reach bedrock, blue or gray shale, or dense unweathered stone.
- Bartlesville heave and settlement: What does this case show about Oklahoma foundations?
- A single building can show both heave and settlement. Here the engineer ordered the work so the settled perimeter was piered first and the heaved interior was leveled afterward.
- Can a building settle and heave at the same time?
- Yes. Here the engineer found perimeter settlement on three sides of one unit and heave of the interior slab, and specified piering the perimeter first, then leveling the interior.
- Bartlesville heave and settlement: How deep did the engineer want the piers?
- Deep enough to reach bedrock, blue or gray shale, or dense unweathered stone. The report described a bearing material, not a fixed depth or pressure.
- Bartlesville heave and settlement: What else did the engineer recommend besides piers?
- Plumbing leak detection on sewer, supply and shower pans, a new roof, repair of spalled concrete, and a new gutter system with downspout extensions.
Why did a Bixby engineer want a tree removed before piering a corner?
Cracking was worst at the corner beside a tree on active clay; the engineer listed tree removal first, then 3 steel piers at least 10 ft below the footing.
- Bixby tree, then corner piers: What did the house show?
- Stone veneer separations and hairline to 1/4 in. cracks, some previously patched, around the chimney and on the north, south and west walls.
- Bixby tree, then corner piers: What did the engineer find was causing it?
- Shrink-swell movement of active clay soil, with the tree at the northeast corner as a contributor. No soil report was available.
- Bixby tree, then corner piers: What repair was specified?
- Remove the tree at the northeast corner; Then underpin the northeast corner with 3 piers, shown at about 9 ft spacing on the plan.
- Bixby tree, then corner piers: What does this case show about Oklahoma foundations?
- On clay soils, trees draw water out of the ground beneath nearby foundations during dry spells, the clay shrinks, and the result is settlement with cracking that often shows around windows and doors.
- Bixby tree, then corner piers: In what order did the engineer want the work done?
- Tree removal was recommendation number one. The 3 corner piers were to be installed after the tree was gone.
- Bixby tree, then corner piers: Did the slab need repair?
- No. The engineer found the slab movement not severe enough to repair; the garage slab cracks were rated non-structural.
- How deep were the piers specified?
- At least 10 ft below the bottom of the footing, driven to refusal on firm strata, with the detail showing bedrock (blue shale).
Why did a Claremore church addition's floor drop 1 to 3 inches?
The engineer found soil consolidation under the slab and a possible void or plumbing leak, and specified 16 steel piers at least 12 ft deep plus slab support.
- Claremore church addition slab: What did the building show?
- The engineer inspected the building in April 2025, limiting the inspection to the southeast addition. The building is one-story wood frame with brick veneer. The addition sits on a slab-on-grade with a continuous perimeter spread footing and stem walls.
- Claremore church addition slab: What did the engineer find was causing it?
- The engineer found consolidation and settlement of the underlying soil beneath the slab in active clay, with a suspected void or under-slab plumbing leak.
- Claremore church addition slab: What repair was specified?
- Slab:
- Claremore church addition slab: What does this case show about Oklahoma foundations?
- Leaks are a known cause of localized slab movement. ASCE's homeowner guide for shrink-swell soils states that leaks in sewer or water lines provide a localized source of water that may lead to localized foundation movements.
- Claremore church addition slab: What lift tolerance did the engineer set?
- The slab was to be lifted and leveled to within 1/2 to 3/4 in.
- Claremore church addition slab: Why test plumbing before and after foundation repair?
- The engineer suspected a plumbing leak under the slab and required a plumbing test both before and after the repair.
- When does a cracked slab get replaced instead of stitched?
- The engineer specified stitching for ordinary cracks, and replacing the slab with #3 bars at 18 in. each way, doweled to the existing concrete, if it is heavily cracked.
Why did a Tulsa house with 23 piers need pier work again in 2026?
Footings kept moving at existing pier locations, and drainage was poor. The engineer specified adjusting the old piers or adding new steel piers, plus gutters.
- Tulsa piers needing readjustment: What did the house show?
- The house is a one-story wood-frame residence with brick veneer and siding. It sits on poured concrete footings with stem walls and a slab floor. The file records a long repair history:
- Tulsa piers needing readjustment: What did the engineer find was causing it?
- The record describes continued exterior footing movement at the existing pier locations, together with poor surface drainage around the house. This was the second adjustment cycle in about four years after the 2002 installation.
- Tulsa piers needing readjustment: What repair was specified?
- Install steel piers or adjust existing piers at the footings at the sketch locations.
- Tulsa piers needing readjustment: What does this case show about Oklahoma foundations?
- Perimeter water is a recurring driver. ASCE's homeowner guide for shrink-swell soils recommends keeping soil sloped away on all sides (at least 3 inches of fall in 5 feet) and discharging downspouts at least 3 feet from the foundation.
- Can existing foundation piers be adjusted instead of replaced?
- The engineer's scope allowed either: adjust the existing pier at each marked location, or, if a pier is not in place or cannot be adjusted, place a new steel pier there.
- Will adjusting piers return the house to its original level?
- The engineer stated that full recovery to the original position is not guaranteed.
- Why does drainage matter on a house that already has piers?
- The engineer found the grade did not slope away enough and gutters, splash pads and downspout extensions were missing, and called for re-grading and gutters at all eaves along with the pier work.
Why did a Tulsa slab home get wall piers but no slab repair?
Brick cracks showed the east wall footing had moved, but floor differential was under 1 in., so the engineer specified 7 steel piers and no slab work.
- Tulsa east wall piers: What did the house show?
- Brick cracks on the east wall.
- Tulsa east wall piers: What did the engineer find was causing it?
- Shrink-swell movement of active clay soil under the east wall's perimeter footing. A plumbing leak was not confirmed, and the engineer asked for one to be ruled out.
- Tulsa east wall piers: What repair was specified?
- A plumbing test of the supply and drain lines; 7 piers along the east wall at 8 ft spacing on the plan; Steel piers only; any other system needed the engineer's approval.
- Tulsa east wall piers: What happened on the job?
- The repair contractor installed the piers in spring 2025, shortly after the report was issued.
- Tulsa east wall piers: What does this case show about Oklahoma foundations?
- On a floating slab, the perimeter footing and the interior slab are separate pieces and can move by different amounts.
- Tulsa east wall piers: Why didn't the engineer repair the slab?
- The elevation survey found less than 1 in. of differential across the floor, which the engineer judged minor, so only the east wall footing was piered.
- How deep did the piers have to go?
- At least 12 ft below the bottom of the footing, driven to refusal on firm strata; the detail showed refusal on bedrock (blue shale).
- Tulsa east wall piers: What records did the engineer require from the crew?
- A log for each pier giving depth, pier type, diameter, driving pressure and amount of lift.
Why did an Edmond slab house settle again two years after piering?
The engineer found more settlement at piers installed in 2023 plus erosion and poor grading. The fix: adjust or replace 7 piers, add 1, and improve drainage.
- Edmond settlement after piers: What did the house show?
- The engineer inspected the house in November 2025 and issued the report in December. It is a one-story house of about 1,035 sq ft, built about 1967, on a slab-on-grade.
- Edmond settlement after piers: What did the engineer find was causing it?
- The engineer described continued settlement at pier locations and stressed surface water, grading and drainage. Possible under-slab leaks were also raised.
- Edmond settlement after piers: What repair was specified?
- Adjust or replace 7 of the existing piers shown on the report's figure. Replacement piers must be steel; Add 1 new pier on the north side "due to excessive spacing"; Afterward, repair drywall and trim, seal exterior cracks, tuck-point, and use elastomeric caulk.
- Edmond settlement after piers: What does this case show about Oklahoma foundations?
- OKC-area soils include clay subsoils over shale. The USDA describes the Bethany series, with its type location in Oklahoma County, as formed in loess or alluvium over Permian shale. Its subsoil is silty clay loam to clay with 35 to 45 percent clay.
- Edmond settlement after piers: Why would an engineer add a pier to an existing pier layout?
- In this case the engineer added one new pier on the north side 'due to excessive spacing' between the existing piers.
- Edmond settlement after piers: What grading did the engineer suggest?
- Slope the ground away from the house at 1 in. per 12 in. within 4 ft, extend downspouts at least 36 in. or pipe them underground to daylight, and remove beds that trap water.
- Edmond settlement after piers: Is a ceiling crack always a foundation problem?
- No. In this house the engineer attributed a living and kitchen ceiling crack to truss movement and described it as not structural.
Why did an engineer pick helical piers for a Tulsa crawl space home?
A clay tile stem wall and a light converted garage gave push piers little to push against, so the engineer specified 10 helical piers at least 20 ft deep.
- Tulsa helical piers, clay tile wall: What did the house show?
- Brick veneer separations over 1/2 in. on the north side, and veneer-to-trim gaps over 1/4 in. at the northwest and southwest corners; The south door of the converted garage out of square, and interior drywall cracks; Previous underpinning along the north, west and south sides, with no documentation available.
- Tulsa helical piers, clay tile wall: What did the engineer find was causing it?
- With no geotechnical data, the engineer presumed moisture-reactive clay whose shrink-swell causes loss of support and uplift at the perimeter footing. The incomplete gutter system contributed; possible fill or slope issues were noted as beyond the report's scope.
- Tulsa helical piers, clay tile wall: What repair was specified?
- 10 exterior piers under the perimeter footings. Helical piers were specifically recommended because of the clay tile stem wall and the light weight of the garage.
- Tulsa helical piers, clay tile wall: What does this case show about Oklahoma foundations?
- The project record lists the Coweta series mapped at the site. USDA describes Coweta as a shallow, well-drained soil formed from soft Pennsylvanian sandstone interbedded with shale, with the soft rock typically about 15 in. down and harder sandstone at 2 to 5 ft in some places.
- Why helical piers instead of steel push piers?
- The engineer cited the clay tile stem wall and the light weight of the converted garage. Push piers rely on the building's weight as reaction; helical piers are screwed in and do not.
- Tulsa helical piers, clay tile wall: What happens if bedrock is shallower than the 20 ft minimum?
- The spec allowed a shallower depth only with the engineer's approval, and required calling the engineer if a stronger stratum such as bedrock or weathered shale was not reached.
- Tulsa helical piers, clay tile wall: What did the engineer say about the earlier underpinning?
- The house had been underpinned before on three sides with no documentation available. The engineer asked that existing piers be exposed in at least 3 places if a pier-and-grade-beam foundation turned up.
Why did one corner of a Mannford walk-out basement house settle?
The engineer tied it to possible fill consolidation on the south side and roof runoff concentrated at the southwest corner, and specified 8 steel piers.
- Mannford corner settlement: What did the house show?
- The engineer inspected the house in April 2022. The building is a one-story timber-frame house with brick veneer, a partial walk-out basement, and an attached garage that was built as an addition.
- Mannford corner settlement: What did the engineer find was causing it?
- The engineer concluded the house had minor long-term settlement along the south elevation, with possible consolidation of fill as a factor. Roof runoff was concentrated at the southwest corner.
- Mannford corner settlement: What repair was specified?
- The report listed five items:
- Mannford corner settlement: What happened on the job?
- The record shows the repair was carried out in April 2022, within about two weeks of the engineer's report.
- Mannford corner settlement: What does this case show about Oklahoma foundations?
- Roof water is a point source. A roof collects rain over a large area and the downspouts drop it in a few spots. ASCE's homeowner guide for shrink-swell soils recommends gutters and downspouts that discharge at least 3 feet from the foundation into well-drained areas.
- Mannford corner settlement: Can roof water alone damage a foundation and a retaining wall?
- In this case the engineer found roof runoff concentrated at the southwest corner and named it as a contributor both to settlement at that corner and to the buckling of a block retaining wall below it.
- Mannford corner settlement: Why did the engineer specify non-perforated drain lines?
- The goal was to carry downspout water past the retaining wall to the downhill side. A solid (non-perforated) pipe moves the water to its outlet instead of releasing it into the soil along the way.
- Mannford corner settlement: What does a gap between a window frame and brick mean?
- Here a 1/2 in. gap between a window frame and the brick, together with brick cracks at the same corner, was read by the engineer as settlement at the southwest corner.
Why did only one side of a 1958 brick home in The Village need piers?
The east side had settled up to about 1.2 in. on highly plastic clay, so the engineer specified 4 steel piers there and monitoring on the west side.
- The Village east-side piers: What did the house show?
- On the east side the engineer recorded brick cracks of 1/32 to 1/8 in. under the windows, brick pulled about 1/8 in. off the window frame near the southeast corner, a 3/8 in. gap at the frieze trim at that same corner, and interior cracks above the east bedroom windows.
- The Village east-side piers: What did the engineer find was causing it?
- The engineer named highly plastic clay soil, settling through consolidation and moving with moisture change. Rain and drought cycles, drainage, plumbing leaks and trees were listed as the moisture drivers.
- The Village east-side piers: What repair was specified?
- Underpin the east side with 4 steel piers, "hydraulically driven until the foundation starts lifting"; Maximum pier spacing of 8 ft; the plan was not tied to any proprietary pier system; A caution against over-lifting.
- The Village east-side piers: What happened on the job?
- The repair contractor installed the piers in 2025. Its markup of the engineer's plan logged the piers at roughly 9,500 psi driving pressure and recorded about 1/4 to 1/2 in. of lift.
- The Village east-side piers: What does this case show about Oklahoma foundations?
- The soil mapped for the area in the project record is the Renthin series.
- Why weren't piers put on the whole house?
- The engineer judged the west-side cracks (1/32 to 1/16 in.) not significant and recommended monitoring them, with re-evaluation only if movement continued.
- How did the engineer decide when to stop driving the piers?
- The plan said to drive the steel piers hydraulically until the foundation started lifting, at no more than 8 ft spacing, and warned against over-lifting.
- The Village east-side piers: What did the pier log show?
- The repair contractor's markup logged the piers at roughly 9,500 psi driving pressure, with about 1/4 to 1/2 in. of lift.