Basement Waterproofing Seattle
Wet floors, wall seepage, and musty air after Puget Sound rain — engineered drainage for Seattle homes in Seattle metro and older urban foundations.
Engineering-first, NDS-certified drainage
We trace where water enters and seeps at your foundation — roof runoff, grading, footing drains, or hydrostatic pressure under the slab — then design NDS-certified systems to move it off the structure. We serve Seattle alongside Shoreline, Edmonds, and Bellevue from our Lynnwood headquarters.
Signs you may need basement waterproofing
Tap a symptom to read the FAQ — then see how it shows up around Seattle.
Basement waterproofing in Seattle, WA
From wet floors to damp air—we inspect and isolate the exact pathways of water entry to solve your specific problem.
Older Seattle basements – from Ballard to West Seattle – often see hydrostatic push and perimeter drain failures after weeks of rain, not just during a single storm.
If gutters dump next to the footing, downspouts tie into a clogged perimeter drain, or the sump discharge sends water back toward the house, interior pumps alone will not fix the load. We map those paths on site, then scope interior drainage, exterior work, or both.
How we solve wet basements
The right fix depends on where water enters — wall, floor, or both.
Interior drainage & sump
Sub-slab collection and sump systems when floor water or hydrostatic pressure is the main load — or when exterior access is limited.
Exterior membrane & drain tile
Excavation and footing-level drainage when wall leaks need to be stopped at the source — common on hillside and daylight basements.
Sump & discharge fixes
Basin sizing, backup power, and discharge routing when the pump runs but the basement still wets.
Basement waterproofing vs. foundation waterproofing
This page covers wet basement living space — floors, walls, odor, and seasonal seepage. Footing-level exterior membrane and structural footing drainage for Seattle is scoped on our foundation waterproofing page.
Field Manual guides
Plain-language answers from real jobs in Western Washington — read before you commit to a scope.
Ready for a wet-season assessment in Seattle? We inspect first, explain what we find, and scope drainage work that matches how water actually enters your basement. Browse the basement waterproofing hub or read more in the Field Manual.
