Crawl Space Repair in Battle Ground, WA

Battle Ground is the newest of the eighteen cities with published figures apart from Happy Valley. Census American Community Survey five-year estimates for 2019 to 2023 give a median year built of 2002 with a margin of error of one year, 17.8% of homes built before 1980 and 3.1% before 1950.

It also has the most completely mapped ground of any Washington city here: only 0.1% of the area carries no soil drainage class, against 17.8% in Camas and 15.2% in Washougal. Whatever the survey says about Battle Ground, it says about effectively the whole city rather than about the parts that happen not to be urban land.

What it says is 22.7% somewhat poorly to very poorly drained. Roughly a fifth of the ground holds water in the wet season — more than Camas or Vancouver, less than half of what the Tualatin Valley cities carry.

Put the two together and Battle Ground is an unusually predictable place to quote: young houses, moderately drained ground, and no large hidden population of pre-war stock to surprise anyone. A quote here that reaches the top of the published metro ranges is describing a specific problem, and should be able to name it.

A median of 2002 means most Battle Ground crawl spaces are somewhere between fifteen and twenty-five years old, and that age has its own catalogue of failures, distinct from both new construction and the pre-war stock elsewhere in the metro.

Original ground cover is present but has been walked on, dragged across and torn at the access hatch and around piers, so coverage is partial rather than absent. Floor insulation is in place but is the first thing to show a moisture problem: batt that is damp along the perimeter each winter is reporting a rim joist condensation issue, not an insulation issue. Original perimeter drainage exists but is at the age where silting and settlement start, and downspout extensions have often been shortened or removed during landscaping since the build.

That last one is worth singling out because it is the cheapest fix on this list by an order of magnitude and the most frequently skipped. Before anyone prices an interior trench on a house this age, the exterior downspouts and grade should have been looked at and the finding stated either way.

Battle Ground is in Clark County and works to the Washington State Residential Code. Under WAC 51-51-0408 that means under-floor ventilation at one square foot per 300 square feet, six-mil black polyethylene ground cover with joints overlapped at least six inches, and an Appendix AF radon vent system required where ventilation drops below the 1/300 ratio or operable louvers are used. How that compares with Oregon's requirements matters if you are reading a bid from a Portland firm.

Unvented crawl spaces are permitted, with a sealed Class I vapor retarder six inches up the stem walls plus a radon system, or with continuous mechanical exhaust at 1 cfm per 50 square feet. R408.8 is not adopted in Washington. Oregon's requirements differ on all of those points, which is why a contractor's Portland experience does not transfer cleanly.

Nor does the licence. Construction work here requires an active Washington L&I licence; an Oregon CCB licence does not cover it, and the two are not interchangeable in either direction. Verify the licence before signing, not after.

Battle Ground shares Clark County's radon position, which the EPA Map of Radon Zones puts in Zone 1 — predicted average indoor screening level above 4 pCi/L, the highest of the three categories. That is the reason the Washington code clause described above exists: reduce crawl space ventilation below the 1 in 300 ratio, or fit operable louvers, and an Appendix AF radon vent system is required with it.

There is a particular reason to take that seriously on housing this new. A house built around 2002 is comparatively tight to begin with, and sealing its crawl space changes how soil gas moves into it. EPA's guidance is that no zone map decides whether an individual home needs testing and that every home should be tested; the practical version on a sealing job is a test before and a test after.

Battle Ground's flood exposure is creek exposure rather than river exposure. The FEMA Flood Insurance Study for Clark County studies Salmon Creek and the East Fork Lewis River in detail among its flooding sources, and neither behaves like the Columbia. Whether a given address is affected is a FIRM panel question. What it changes about a crawl space, if it is affected, is the design: a space that may take surface water needs a route for the water to leave and equipment placed to survive submersion.