Field notes / Homeowner guide
Signs a foundation needs professional evaluation
Cracks, sticking doors and sloping floors are common in older Los Angeles houses. Some are cosmetic; some are the first visible sign of movement. The useful question is not "is it bad?" but "what has changed, and who should look?"
Written · KB Remodeling
The short answer
Ask for a professional evaluation when a symptom is new, growing, accompanied by others in the same part of the house, or follows a leak, heavy rain or earthquake. Width alone does not decide whether a crack matters.
Who this applies to
Owners of existing houses noticing changes. This guide helps decide when to call someone; it does not diagnose damage, declare a house safe or unsafe, or replace an engineer's evaluation.
01 · When it applies
Why one symptom is rarely an answer
Concrete shrinks as it cures, wood framing dries and shifts, and stucco cracks at window corners on many houses that are not moving. The same visible crack can come from shrinkage, seasonal soil moisture, a plumbing leak, poor drainage, past repairs or ongoing settlement.
That is why a photo or a crack-width chart cannot tell you the cause. What helps is context: where the symptom is, whether it is changing, and what else is happening nearby.
Ask yourself
- Is the symptom new, or has it always been there?
- Is it in one area of the house or spread around?
02 · Comparing the options
Symptoms that are usually worth watching, and those worth a visit
The table separates symptoms that are commonly cosmetic from those that more often justify a professional look. It is a prompt for action, not a diagnosis; exceptions run both ways.
| What you notice | Often | Worth a professional look when |
|---|---|---|
| Hairline cracks in drywall or stucco | Shrinkage or normal movement | They reopen after patching, grow, or cluster in one area |
| Doors or windows that stick | Humidity, hinges or paint | Several stick in the same part of the house, or gaps appear above doors |
| Floors that slope or feel soft | Old framing or settled supports | The slope is new or increasing, or the floor feels springy |
| Cracks in the foundation concrete | Shrinkage cracks in older concrete | Edges are offset, crumbling, or wider at one end; or water comes through |
| Gaps between trim, cabinets or tile | Seasonal wood movement | Gaps keep widening or tile cracks in a line |
| Water in the crawl space or against walls | Grading, gutters or irrigation | Always worth addressing; persistent water affects soil and wood |
| Changes after an earthquake | Minor finish damage | Anything new at the foundation, chimney or cripple walls |
03 · What to ask for
Record change before anyone visits
A simple record makes any evaluation more useful. Photograph each symptom with a ruler or coin for scale, note the date, and repeat the same photo every few weeks or after storms. Mark crack ends lightly with pencil and a date so growth is visible.
Write down when you first noticed each item, any leaks or plumbing repairs, and earlier foundation or retrofit work you know about.
Ask yourself
- Do you have photos from when you bought the house?
04 · The decision
Who to call, and what each can tell you
A contractor evaluation looks at visible conditions and practical next steps. A licensed structural or geotechnical engineer diagnoses causes and designs solutions. A city inspector checks permitted work; they do not diagnose your house on request.
If movement, soil or structural capacity is in question, the engineer's evaluation is the one to rely on. Check any contractor's license with the state before work.
Ask yourself
- Is the question what is visible, or what is causing it?
Source for this section
05 · Next step
Regional hazard maps are context, not a diagnosis
The California Geological Survey publishes seismic hazard zone maps for liquefaction and landslide study areas. They show where investigation may be required for some projects; they do not describe the soil under a particular house or explain a specific crack.
Use them as background for questions to a professional, not as an answer.
Ask yourself
- Has a soils report ever been prepared for the property?
Source for this section
A scenario to consider
An owner notices a bedroom door sticking and a new diagonal crack above it. Photos taken monthly show the crack lengthening after the rainy season, and the downspout nearby empties against the wall. Both facts go to the evaluator: the pattern, the timing and a possible water source.
Planning scenario
Bring this to your conversation
- Photograph each symptom with scale and date
- Mark crack ends with pencil and date
- Note leaks, plumbing work and drainage changes
- List earlier foundation or retrofit work
- Gather any reports, permits or plans
- Note crawl-space access and anything blocking it
One more question
Is a crack wider than a certain size always structural?
No. Width is one clue among many. Direction, offset, change over time, location and other symptoms matter more than a single measurement. A professional evaluation looks at the pattern.
Official references
Research the property · Web resource · English source
California Geological Survey — Seismic hazard zones (SHMA)Use this for: Check whether a regional seismic hazard study zone applies; it does not describe a specific home's soil.
Prepare plans and ADUs · Web resource · English source
LADBS — Plan review and permittingUse this for: For City of Los Angeles parcels, find LADBS plan review, online permits and appointments.
Check professionals · Web resource · English source
California Contractors State License Board — Check a contractor licenseUse this for: Check the current contractor record before hiring; a number alone does not establish scope or status.
For requirements specific to your property, consult the local reviewing authority.
About this guide
Published by KB Remodeling from the official sources cited. It is not attributed to an individual author and does not claim review by an architect, engineer or attorney. We receive remodel, ADU, new-home and rebuild inquiries; scope, licensing and location are reviewed before any next step.