Overview
Inspect under sinks, around windows, in the basement or crawl space, and attic for water stains or mold. Catching water damage early prevents costly structural repairs.
Step-by-Step Guide
Inspect under every sink in the house
Open the cabinet doors under every kitchen and bathroom sink. Look for warped or stained cabinet floors, active drips, corroded supply valves, and musty odors. Run the faucet for 30 seconds and check all connections for leaks. Feel the P-trap for moisture.
Examine ceilings and walls for stains
Walk through every room and look up. Water stains on ceilings appear as yellowish-brown rings or discolored patches. On walls, look for bubbling or peeling paint, warped drywall, or soft spots. Pay special attention to areas below bathrooms and near exterior walls.
Check around all windows and exterior doors
Inspect the drywall and trim around every window frame for discoloration, soft spots, or peeling paint. Feel the window sills for dampness. Check exterior door thresholds for rot or staining. Look at the caulking on the outside — cracked or missing caulk is a water entry point.
Inspect the basement or crawl space
Look for white mineral deposits (efflorescence) on foundation walls — this indicates past water penetration. Check for standing water, damp spots, or water lines on walls. Inspect the sump pump pit if one exists. In crawl spaces, look for wet insulation, mold on joists, and standing water on the vapor barrier.
Examine the attic
Look at the underside of the roof sheathing for dark stains, mold, or daylight coming through. Check around roof penetrations (plumbing vents, chimney, exhaust fans) for water staining. Feel the insulation near eaves for dampness — this can indicate ice dam damage.
Check around toilets, tubs, and showers
Feel the flooring around the base of each toilet for softness or sponginess — this indicates a failed wax ring. Check the caulk lines around tubs and showers for gaps or mold. Press on the tile surround near the bottom of showers — soft spots mean water has penetrated behind the tile.
Document everything you find
Photograph and note every issue with its location. Rate each finding as cosmetic (stain only), active (currently leaking), or structural (soft wood, sagging). This documentation is essential for prioritizing repairs and for insurance or warranty claims.
What You'll Need
Tools
- - Flashlight
- - Moisture meter (optional but very helpful)
- - Screwdriver (for probing soft wood)
- - Camera or smartphone
- - Step ladder
Cost Estimates
DIY Cost
$0–$50 (flashlight and moisture meter rental)
Professional Cost
$200–$500 (professional water damage inspection)
Safety Tips
- Wear a dust mask in the attic and crawl space — these areas may contain mold spores or insulation fibers.
- Do not walk on attic insulation between joists — step only on the joists or a board placed across them.
- If you encounter what appears to be mold covering more than 10 square feet, do not disturb it — call a mold remediation specialist.
- Turn off the water main before probing around supply lines to avoid triggering a leak.
When to Call a Professional
Call a professional if you find active leaks, widespread mold, soft or sagging structural wood (joists, studs), or if a moisture meter shows elevated readings in walls or floors. A home inspector or water damage restoration company can assess the scope.
Pro Tip
A $30 pin-type moisture meter from the hardware store is one of the best investments for a new homeowner. It can detect hidden moisture behind walls and under floors long before stains appear.
Common Mistakes to Avoid
- Only checking obvious areas and missing hidden spots like inside closets backing exterior walls.
- Assuming a dry stain means the problem is fixed — it may be seasonal and return during rainy months.
- Ignoring musty smells as 'just an old house' — musty odors almost always indicate hidden moisture or mold.
- Not checking the grading around the foundation exterior — soil should slope away from the house.
- Overlooking the hot water heater drain pan — a rusted or full pan indicates a slow leak.
Local Professionals in Ames

Ames Housing Market
Median Household Income
$60,102
Median Home Value
$263,800
Median Rent
$1,040/mo
Homeownership Rate
42.9%
Population
66,112
Median Year Built
1991
Source: U.S. Census Bureau, ACS 2023 5-Year Estimates
Fair Market Rents — Ames
Studio
$972/mo
1 Bedroom
$1,026/mo
2 Bedroom
$1,153/mo
3 Bedroom
$1,601/mo
4 Bedroom
$1,934/mo
Source: HUD FY2026 Fair Market Rents — Ames, IA HUD Metro FMR Area
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Related How-To Guides
Schedule a Deep Clean Before Moving In
Clean the house thoroughly before moving in — especially kitchen, bathrooms, and inside cabinets. An empty house is the easiest time to deep-clean every surface.
Document the Home's Current Condition
Take photos and video of every room, including close-ups of existing damage. This documentation protects you for insurance, warranty claims, and future resale.
