What does a full foundation inspection include?

Reviewed by Preston, Oklahoma foundation repair consultant · Updated 2026-10-14

In short: A full foundation assessment moves from background research to an interview about the home's history, a walk around the outside and inside, a floor elevation survey, a crawl space or basement check where present, and a written report. Engineering guidelines describe these steps in levels, from a walk-through "first impressions" visit up to one with soil sampling and plumbing tests. Each step feeds the main question: what is moving, and why.

What are the levels of investigation?

The Texas Section of the American Society of Civil Engineers (ASCE) defines three levels of residential foundation investigation ¹:

The Foundation Performance Association (FPA) uses a similar structure, with a survey elevation plan and a plan of observed distress at Level B ².

1. What desk research happens before the visit?

Background on the lot can be gathered before anyone arrives:

• Soil map. Web Soil Survey, the USDA soil map, shows the mapped soil series, soil data and use ratings for a chosen area of interest ⁴. See the Soil Series Index.
• Flood map. FEMA's Flood Map Service Center can be searched by address for the flood map panel and a printable flood map for that location ⁵.
• Weather. The Oklahoma Mesonet runs 120 automated weather stations with at least one in every county, giving local rainfall records for the weeks before a visit ⁶. See Mesonet for foundation pros.

2. What is asked in the homeowner interview?

ASCE Texas guidelines call for interviewing the occupant, owner and client, where possible, about the property's history and the structure's performance, and reviewing any documents such as construction drawings or geotechnical reports ¹. Topics that bear on soil moisture and movement include:

• Whether cracks show progressive or seasonal movement ⁷
• Water bills, known leaks and plumbing work; the ASCE homeowner guide recommends monitoring water bills along with foundation performance ⁷
• Sprinkler location and watering habits ⁷
• Trees planted or removed near the house ¹⁷
• Earlier repairs and their records ²

3. What is checked on the exterior walk?

The exterior walk records cracks in brick, gaps at windows and doors, and separation of flatwork from the house ⁷. The ASCE homeowner guide recommends checking that the ground within 5 feet of the foundation drains water away ⁷. Home inspection standards likewise include grading, surface drainage and retaining walls where they may affect the structure through moisture ³. See surface drainage and grading.

4. What is checked on the interior walk?

FPA's guideline calls for recording distress on every interior level and the exterior, noting whether it is on a wall, ceiling or floor, its position relative to doors and windows, and any sign of earlier repair; crack widths may also be recorded ². A crack width scale such as the UK Building Research Establishment categories grades cracks from hairline to over 25 mm, and also weighs the number of cracks and whether they are growing ⁸. Patterns are explained in the distress pattern library.

5. How is the elevation survey done?

The floor elevation survey is the Level B step ¹. FPA calls for an instrument accurate to 1/8 inch or better, a repeatable reference point and readings about every 30 to 100 square feet, corrected for floor coverings ². Details are on elevation surveys.

6. What is checked in the crawl space or basement?

Home inspection standards require describing the foundation type and the crawl space access, and reporting active water penetration, wood in contact with soil and signs of possible foundation movement ³. Inspectors are not required to enter crawl spaces that are not readily accessible or where entry could endanger them ³.

7. How are the findings analyzed?

Distress locations are compared with the elevation contour map, the likely mechanism is identified (see heave vs settlement), and moisture sources are listed. Level C adds tests the engineer considers appropriate, such as soil sampling and plumbing testing ¹. ASCE Texas guidelines call for testing water and drain lines when lifting is part of the repair ¹.

8. What goes in the written report?

ASCE Texas guidelines list possible report contents such as the authorization and scope, property description, information sources, collected data, assumptions, analysis, conclusions, recommendations and limiting conditions ¹. FPA adds a list of reviewed documents, the survey elevation plan and the distress plan for a Level B report ².

Home inspection versus engineering evaluation

Home inspection standards require reporting possible foundation movement, such as cracked drywall or brick, out-of-square door frames and unlevel floors, but state that inspectors are not required to provide engineering services or report on the adequacy of structural systems ³. See working with engineers.

Related

• Elevation surveys
• Heave vs settlement
• Method selection matrix
• Real estate, disclosure and inspections
• Symptom matrix