Ask House Spouse · Exterior & Weatherproofing · Gutters & Downspouts
Do I need downspout extensions on my gutters?
Short answer
Yes — every downspout should discharge water at least 4–6 feet from the foundation, and ideally into a splash block or buried drain. The single cheapest crawlspace-moisture fix in the PNW is $15 flexible downspout extensions on every corner. It takes an hour and prevents the majority of foundation damp problems.
What proximity does
Water that hits the ground within 2 feet of the foundation follows the soil down along the concrete and enters the crawlspace. Move it 6 feet out and it drains away instead. In heavy PNW rain, this difference is thousands of gallons per storm.
Cheap vs. permanent
Flexible plastic extensions are $10–$20 each and last a few years. Buried rigid pipe to daylight is $40–$60 per foot installed but permanent — the right call if your yard slopes toward the house or you already have a moisture issue.
Signs you already need this
Musty crawlspace smell, efflorescence (white salt) on foundation walls, mud along the base of siding, or moss growing at ground level on shaded walls.
What we see on Home Health Assessments
Around 74% of PNW roofs we assess show active moss establishment — accelerates shingle wear by an estimated 3–5 years if untreated.
Caught early on assessment: $220–$650 · Left until failure: $3,500–$22,000
Based on real experience across Snohomish and King County, exterior & weatherproofing issues like this are among the ones homeowners most often miss until they become expensive. Our Home Health Assessment catches them early — while they're still a maintenance item, not a repair.
How the Home Health Assessment worksServices we'd bring to this job
Related questions
Exterior & Weatherproofing · Gutters & Downspouts
How often should I clean gutters in the Pacific Northwest?
Twice a year minimum — once in late fall after the leaves drop (mid-November) and once in spring (late March). Homes surrounded by Douglas fir, cedar, or big-leaf maple need a third mid-fall cleaning, typically late October. Skipping cleanings is the #1 cause of preventable siding and foundation damage we see.
PNW Seasonal · Fall Rain Prep
What should I do to prepare my house before the PNW rainy season?
Six items, mid-October: clean gutters and downspouts, check and extend downspout runouts, seal any exterior wood cracks with caulk, verify the sump pump works (if you have one), swap furnace filter, and test every smoke and CO detector. This routine takes half a day and prevents 90% of the wet-season damage we get called for.