Crawl Space Repair in Kenmore

King County describes the Sammamish River as running 14 miles through Kenmore, Bothell, Woodinville and Redmond. The county’s 2016 mapping of potential landslide hazards along its river corridors included the Sammamish River, and across all the corridors it studied it mapped 930 deep-seated landslides. Neither document maps individual Kenmore lots. The county’s flood page gives no Kenmore flood record, and this site has not read Kenmore’s own flood-hazard or critical-area maps.

The soil survey shows two kinds of ground that ask for opposite things. Norma sandy loam, which it rates poorly drained, covers 4.1% of Kenmore’s mapped area and makes up most of the city’s 6.4% in the wetter drainage classes. Kitsap silt loam on 15 to 30 percent slopes covers 5.2%, and a unit the survey calls “Alderwood and Kitsap soils, very steep” another 2.2%. The map unit says what the soil is, not how near it lies to the river.

Under a house on poorly drained ground, water can rise into the crawl space from below and stay for the whole wet season, and collecting it with a drain and a sump may be part of the answer; a sump pump installation runs $1,600 to $3,125 on this site’s cost guide, before sales tax. On a slope, the harder question is where the collected water goes, because downhill may mean a neighbor’s foundation or the face of the slope. Ask Community Development what applies to the parcel before a drain is trenched, and see what a sump pump installation covers.

Kenmore is mapped in three soil survey areas, an arrangement only Federal Way shares among the nineteen places. Most of the city lies in the survey area that also covers the Eastside cities, where Kenmore’s largest map unit is Alderwood gravelly sandy loam on 8 to 15 percent slopes, 35.7% of the mapped area, rated moderately well drained. Another part lies in the newer urban survey that covers Seattle, mapped as Urban land-Alderwood complex on three slope classes (17.5% together), and the Eastside survey area maps another 6.1% as Urban land on its own.

None of those urban units has a drainage class. That is why 28.1% of the mapped area is unrated, and only 0.4 points of it is open water. Of the rest, 54.0% of the mapped area is moderately well drained, 7.4% somewhat excessively drained (mostly Indianola loamy sand and Everett very gravelly sandy loam) and 6.4% in the wetter classes.

So Kenmore’s wet-rated share describes the roughly three quarters of the city the survey rates, not the whole of it. A house on one of the Urban land units has no soil rating at all, and even a rated one is rated for a map unit, not a lot. In both cases the crawl space in February tells more than the map: damp air and condensation on cold surfaces point one way, water on the ground another. High humidity in a crawl space covers the first.

Kenmore did not build in one burst. The Census counts 1,455 housing units from the 1960s, 1,286 from the 1970s, 2,194 from the 1980s, its peak, then 1,158, 1,161 and 1,230 in the three decades after. Before 1960 there are 1,126 units, 11.5% of the city, and since 2020, 151.

That even spread means a neighbor’s crawl space is a poor guide to yours. A house from the 1960s or 1970s may have had its ground cover replaced once, patched several times or never laid, and its floor insulation may date from any decade since. One from the 2000s or 2010s most likely still has what it was built with, and the question there is whether it has held up: a ground cover still lapped and intact, insulation still against the subfloor, vents not buried by later landscaping. Find out which kind of crawl space you have before comparing quotes; vapor barrier versus encapsulation explains the two scopes most often proposed.

Seattle’s Sand Point station is 4.3 miles from Kenmore’s Census internal point, the fifth-shortest distance to a published station among the nineteen places, and its 1991–2020 annual normal is 37.82 inches. Two more stations fall inside 15 miles: the Everett airport at 11.0 miles, 33.37 inches, and Monroe at 13.5 miles, 50.77 inches. Almost all of the 17.4-inch spread among them comes from Monroe, the wettest of the three.

Monroe is also the cold record. It averages 60.0 nights a year at or below freezing and 5.6 at 20°F or below, the most hard-freeze nights of the eight published stations, against 25.0 and 0.8 at Sand Point. The dataset cannot say which a Kenmore house is closer to in practice; Sand Point is the nearest record, and Monroe is a reason not to leave crawl space pipes uninsulated on the strength of it.

Kenmore and its ZIP code coincide. ZIP code 98028 covers all of the city’s land and lies entirely inside it, which of the nineteen places is true only here and on Mercer Island. A 98028 address is a Kenmore address, and the City of Kenmore is its permit authority: building permits come from Community Development, through MyBuildingPermit.com. This site has not read which crawl space work Kenmore exempts from a building permit, so ask before assuming a scope needs none.

Electrical permits do not come from the city. Kenmore says plainly that all electrical permits in the city are issued and inspected by L&I, and L&I’s own list of cities that run their own electrical programs leaves Kenmore off. A new circuit or receptacle for a sump pump or a dehumidifier is therefore an L&I permit.

The Department of Revenue lists one Kenmore rate, 10.3% for October 1 to December 31, 2026. It applies to the whole contract price for repair work on a home, labor and materials together, and the ranges on the cost guide leave it out.