Basement Expert Field Manual
Practical answers from real jobs in Seattle, Snohomish County, and the Eastside — for homes and commercial buildings. Plain language, not textbooks.
From the field
Drainage and waterproofing work follows NDS-certified practices where systems are designed to move water off the structure — not just patch the symptom.
Start with what you’re seeing
Tap the situation that matches — jump straight to the right guide.
For your home
Twelve guides written for Puget Sound homeowners — what to notice, what it usually means, and when to call a pro.

Hydrostatic pressure in Seattle-area basements
Why groundwater pushes against your floor and walls after heavy rain.

Water on the basement floor after rain
Common causes in Western Washington and what to check first.

Do you need a sump pump?
What a sump does in your basement and when it matters in the PNW.

Musty basement & winter humidity
Why basements smell damp in our climate and when it’s more than air quality.

Mold vs. efflorescence on basement walls
White powder, dark spots, and what each might mean for your foundation.

Foundation cracks: monitor or repair?
Which cracks are worth watching before the rainy season.

Bowing or leaning basement walls
What inward movement usually means under soil and water pressure.

Interior vs. exterior French drain
A homeowner comparison — not a sales pitch for one path.

Yard & downspout drainage
Surface water that actually protects (or stresses) your foundation.

Wet basement after a flood — first steps
What to do immediately and what not to ignore.

Exterior basement waterproofing — when it helps
When excavation and exterior systems are worth the disruption.

Crawlspace moisture & PNW soils
Glacial till, seasonal rain, and why crawlspaces flood here.
For your building
Property owners, managers, and facilities — practical basics before mitigation or repair.
Deeper technical library — engineering detail, mold science, sump sizing, and more live in our FAQ archive. Field Manual articles link to those when you want to go deeper.




