What We Look For (And What We Don’t): Foundation, Crawlspace & Basement — Uncovering Structural Clues
The reason I spend time staring at concrete piers and dirty crawlspace walls is because the structural clues down here matter more than anything happening upstairs. You might have new flooring and fresh paint—but if the home is settling, shifting, or collecting water underneath, that’s the stuff that really counts.
My Mindset in a Crawlspace or Basement
I’m not just glancing for water. I’m looking at the support systems. Are piers solid, straight, and continuous? Are they resting on proper footings or makeshift blocks? Is there evidence of movement, like gaps between beams and supports, or diagonal cracking in stem walls?
Foundation systems vary—slab-on-grade, post and pier, basement, stem wall, pilings—but the approach is the same. I’m looking for settlement, shifting, and moisture. I’m also checking whether repairs have been made—and how well. Foam shims and cardboard spacers aren’t load-bearing materials (no matter how clever the last guy thought he was).
Moisture Is the Common Denominator
Water doesn’t belong inside a crawlspace or basement. I check for efflorescence (that white powdery residue from water seepage), dark staining, standing water, and mold-like substances. These may not just mean dampness—they may point to poor drainage or a failing sump pump system.
Sump Pumps: What I Can and Can’t Test
If the sump pump is exposed and I can reach it safely, I’ll inspect its condition. I look for power supply, float switch condition, visible rust or deterioration, and backup battery systems. If there’s standing water or a test button, I may activate it. But I don’t manually fill sump pits, override systems, or perform destructive testing. If it's a sealed system or inaccessible due to safety or design, I’ll document what I can see—and note that further evaluation may be needed.
What I’m Looking For—And What I’m Not
- ✅ I’m looking for: uneven floors, cracked foundation walls, displaced piers, sagging framing, long-term moisture, and signs of movement.
- ❌ I’m not looking to: conduct soil tests, certify foundation engineering, test underground drainage, or predict how the home will settle over the next decade.
When I Flag a Structural Concern
If I see horizontal foundation cracks, wall bowing, improper support spacing, or sloped floors beyond normal tolerance, I’ll let you know. These signs don’t always mean disaster—but they do mean a structural contractor should take a deeper look. Just like a knee specialist doesn’t diagnose from an x-ray alone, you need boots-on-the-ground expertise for repairs and solutions.
FAQs: Understanding Foundation and Basement Inspections
Do you test the sump pump?
Only if safely accessible and testable without altering the system. I’ll report visible condition and note if testing was limited or not possible. If it’s sealed, damaged, or inaccessible, I’ll recommend evaluation by a plumber or drainage contractor.
Will you tell me if the foundation is bad?
I’ll report cracks, movement, sagging, or signs of distress. But a full engineering opinion is beyond the scope of a home inspection. My goal is to tell you what’s visible, and whether it warrants a second look.
Do you enter crawlspaces even if they’re tight?
Yes—if safe and accessible. I’ll crawl, duck, and inch through to get eyes on the piers and framing. If entry is blocked or dangerous, I’ll document that in your report.
What foundation types do you inspect?
I inspect slab, post and pier, stem wall, and basement foundations. Each has different issues—but the same red flags: water, settlement, and failing support systems.
→ Next up: Post 14: Do You Have Good Bones? What a Structural Inspection Reveals
← Previously: Post 12: Exterior Systems — Drainage, Siding, and What Can Let Water In
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