Guides

Inspections, surveys, drainage, trees, weather and working with engineers.

• Are there gypsum sinkholes in western Oklahoma?Yes, in places. Gypsum near the surface can dissolve in groundwater, leaving voids that let the ground above sag or collapse.
• Can an under-slab plumbing leak move an Oklahoma foundation?Yes. A leak under a slab can make expansive clay swell and lift the floor or soften and wash out looser soil, so the leak must be fixed for a lasting repair.
• Can trees damage a foundation in Oklahoma clay soil?Large trees rarely push a foundation. They mainly cause damage by drawing water from clay, which shrinks and lets the nearby part of the house settle.
• How can Oklahoma Mesonet soil moisture data explain foundations?The Oklahoma Mesonet is a free statewide network reporting soil moisture. Its shallow readings show whether ground is drier or wetter than usual, as trends.
• How deep do foundation piers need to go in Oklahoma shale?Shale weathers top-down into clay; piers aim for firmer material below the shrink-swell layers, and Oklahoma push pier records run about 8 to 16 feet.
• How do erosion, creeks and slopes threaten Oklahoma foundations?Runoff can undermine slab edges, creeks can cut into banks, clay on slopes can creep, and underground flow can carry soil away and leave voids.
• How do freezes and frost affect Oklahoma foundations?Frost is a secondary issue in most of Oklahoma; freezes mainly affect porches, steps, driveways and plumbing, more so in the northwest and Panhandle.
• How do Oklahoma drought and wet cycles move foundations?Oklahoma clay shrinks in drought and swells when wet, so foundations drop at the edges during drought and can be pushed back up when heavy rain returns.
• How do Oklahoma storms, floods and ice affect foundations?Water is the main way severe weather reaches a foundation: floods and heavy rain saturate clay and wash out soil, while wind and tornadoes act on the structure.
• How do Oklahoma's geologic regions affect foundations?Pennsylvanian shales and sandstones in the east and Permian red beds in central and western Oklahoma shape soil, clay content and depth to firm material.
• How do you tell foundation heave from settlement?Heave is ground rising, usually as clay takes on water; settlement is ground dropping. Floor surveys over time, the season and water sources tell them apart.
• How does yard drainage and grading affect an Oklahoma foundation?On expansive clay, slopes toward the house, downspouts at the wall and sprinklers wet soil unevenly and drive movement; fixing drainage is a first step.
• How far apart are foundation piers in Oklahoma?Spacing depends on wall load, pier capacity and how far the beam can span. Oklahoma steel push piers are commonly set about 7 feet apart.
• How far out of level can an Oklahoma foundation be?There is no single allowed number. Engineers judge overall tilt, deflection and resulting distress against published guidelines.
• How is a foundation elevation survey done?Floor heights are measured from one reference point and mapped as contours, then tilt and deflection are checked against limits such as L/360 and 1 percent.
• How is a settled foundation lifted, and what happens after?Piers raise settled areas toward original height, aiming for the best practical lift, not flat, followed by plumbing checks, a new survey and pier records.
• Is it earthquake damage or soil movement in my Oklahoma home?Earthquake damage appears at a set moment tied to a recorded event; expansive clay damage builds over months or years and changes with the seasons.
• What affects the cost of foundation repair in Oklahoma?Scope drives cost: the cause of movement, foundation type, number and depth of supports, access, drainage and plumbing work, engineering, permits and follow-up.
• What are loess and collapsible soils in western Oklahoma?Loess is wind-deposited silt, found mainly on Oklahoma Panhandle tablelands. Loose, dry wind-laid soils can collapse when wetted, the reverse of swelling clay.
• What bedrock is under Oklahoma City homes?Mainly Permian red-bed Hennessey shale and Garber sandstone; the clay soils formed from these rocks, not the rock itself, cause most shrink-swell movement.
• What bedrock is under Tulsa, Oklahoma homes and how deep is it?Mostly Pennsylvanian shale with sandstone and limestone; upland borings usually hit rock within 4 to 20 feet, river banks have 18 to 35 feet of sediment.
• What causes common foundation symptoms in Oklahoma homes?Most foundation symptoms have more than one possible cause; in Oklahoma, clay soil that shrinks and swells with moisture is widespread.
• What do foundation crack patterns in a house mean?Stair-step brick cracks, cracks at door and window corners, sticking doors and sloping floors are movement clues, checked against floor elevation surveys.
• What do soil test numbers for expansive clay mean?The plasticity index from Atterberg limits is a common quick indicator of shrink-swell, while swell tests measure movement and pressure directly.
• What does a full foundation inspection include?It covers desk research, a homeowner interview, exterior and interior walks, a floor elevation survey, a crawl space or basement check and a report.
• What foundation does my Oklahoma house have, by year built?Older Oklahoma homes more often have crawl spaces or basements, while postwar and later homes are mostly on slabs or pier-and-beam.
• What is perched water and how does it affect Oklahoma homes?Perched water is rain backed up above a dense clay layer; in eastern Oklahoma it can wet crawl spaces, seep into basements and saturate footing clay.
• What is shrink-swell clay and the active zone under a foundation?Expansive clay swells when wet and shrinks when dry; the active zone is the layer, often several to over 10 feet thick, whose moisture changes enough to move.
• What soil types are in the Oklahoma City metro?Mostly soils from Permian red shale, claystone and sandstone. Clay-rich Renfrow and Kirkland shrink and swell strongly; sandy Dougherty and Lucien move less.
• What soil types are in the Tulsa metro and how do they behave?Tulsa soils formed mostly from shale and sandstone. Shale soils are clayey and can shrink and swell; sandstone soils on hills are loamy and shallow to rock.
• When do I need an engineer for foundation problems in Oklahoma?A licensed engineer gives an independent, sealed opinion on the cause and needed repair. Lenders, insurers and buyers may ask for an engineer's report.
• When do Oklahoma foundations move during the year?Clay swells in wet springs, shrinks in hot, dry midsummer and partly rewets with fall rains, so cracks often open in late summer and narrow in spring.
• Why did Oklahoma earthquakes increase, and can they damage houses?Quakes rose sharply after 2009, mainly linked to deep disposal of oil-and-gas wastewater; moderate quakes can crack plaster and masonry.
• Why do Oklahoma foundations move, in plain English?Most Oklahoma foundation movement comes from clay that swells when wet and shrinks when dry. Repair aims to stop damaging movement, not reach a level floor.
• Why does a home addition crack away from the original house?An addition is often a separate foundation at a different depth on different soil prep, so on Oklahoma clay the two move differently and crack at the joint.
• Why does fill soil under a house cause settlement?Poorly compacted fill, or fill with organic material or debris, can keep settling for years, often on one side of the house, apart from the seasonal pattern.
• Why does some Oklahoma clay swell more than others?Swelling depends mostly on clay minerals. Montmorillonite, a smectite, takes water between its layers and swells most; kaolinite swells much less.