Crawl Space and Rot Assessment in Beaverton, OR
The 1960s and 1970s Beaverton housing stock has a specific vulnerability: interior support is typically a grid of short wood posts on individual concrete pads sitting directly on the crawl space soil, rather than a continuous girder wall. Each of those posts is an independent point of failure and each is in contact with ground that stays damp for most of the year.
Decay starts at the post base where it meets the pad, because that joint holds water. A post can lose most of its bearing area at the bottom two inches while the rest of it remains completely sound, and there is no symptom above the floor until enough posts have gone for the floor to move.
What makes this era worse than it needs to be is that many of these crawl spaces were built with no vapour barrier at all, and later energy retrofits then blocked the vents that were doing the drying. The combination — moisture from below, no ventilation to remove it — is more damaging than either alone and is common enough here to be worth looking for specifically.
What We Look At Here
- Every post base probed at the pad contact, where decay concentrates
- Pad settlement into soft crawl space soil, distinct from decay of the post itself
- Girder condition above the posts and at any splice
- Presence and coverage of a ground vapour barrier
- Ventilation, including vents blocked or sealed by later insulation work
- Standing water, drainage entry points and evidence of a seasonal high water level
More on the service itself: Water & Rot Damage Assessment. More on the area: Beaverton.
Questions
Frequently Asked Questions
Should I seal the crawl space vents on my 1970s Beaverton house?
Not without addressing ground moisture first. Sealing vents on a crawl space with no vapour barrier removes the only drying mechanism while leaving the moisture source, which accelerates decay at post bases and girders.