Why Portland Homes Get Wet
Portland's climate creates persistent moisture exposure unlike drier regions. Rain falls for roughly 154 days annually, concentrated between October and May. This isn't heavy downpour rain - it's persistent drizzle that keeps everything damp for months.
Houses built before modern moisture management practices often lack proper vapor barriers, drainage planes behind siding, and adequate foundation waterproofing. They were built for the climate as it was understood then, not with today's building science.
Common Entry Points
Water enters Portland homes through predictable locations: roof valleys and flashing, window and door frames (especially on west-facing walls that take weather), foundation walls below grade, and anywhere wood contacts soil or concrete. Inspectors check these areas systematically.
The West Side Problem
Portland's prevailing weather comes from the west. West-facing walls take the brunt of wind-driven rain. Homes with covered porches or deep overhangs on the west side fare better than those with exposed siding. You'll often see more moisture damage on a home's west side than east.
Crawlspaces: Portland's Problem Child
Many Portland homes have crawlspaces rather than basements or slab foundations. These dirt-floored spaces under the house are moisture magnets. Portland inspectors spend considerable time evaluating crawlspace conditions.
What Inspectors Look For
Standing water or saturated soil indicates drainage problems. Moisture on floor joists and subfloor suggests vapor rising from the ground. Visible mold or fungal growth means moisture has been present long enough to create biological activity. Wood damage to structural members is the worst-case finding.
Vapor Barriers
Modern practice calls for 6-mil polyethylene covering the crawlspace floor to block ground moisture. Many older Portland homes lack this barrier or have deteriorated plastic that no longer functions. Adding or replacing a vapor barrier is relatively inexpensive but requires crawling through the space to install it.
Ventilation Debate
Traditional wisdom said crawlspaces should be vented to the outside. Current research suggests that in Portland's climate, vented crawlspaces may actually pull in humid outside air during summer, causing condensation. Encapsulation (sealing the crawlspace) is increasingly recommended but costs $3,000-8,000.
Wood Rot: The Real Concern
Moisture itself isn't the problem - wood rot from sustained moisture is. Portland inspectors probe wood members with an awl or screwdriver to check for softness indicating decay.
Hotspots for Rot
Bottom edges of exterior door frames where splash-back hits. Window sills, especially on west-facing windows. Trim boards at corners where water runs down. Deck ledger boards attached to the house. Any wood within 6 inches of soil. These are the first places to check and the first places to fail.
Repair vs. Replacement
Small areas of rot in non-structural trim can be repaired with epoxy consolidants and filler. Rot in structural members (rim joists, posts, beams) typically requires full replacement of the damaged section. Costs range from $200 for trim repair to $2,000+ for structural work.
Basement Water
Portland homes with basements frequently show signs of water intrusion. The question is degree. Some dampness during heavy rain is almost unavoidable in older construction. Active water pooling indicates more serious problems.
Efflorescence
White mineral deposits on foundation walls indicate water has moved through the concrete, evaporated, and left minerals behind. This is common and not necessarily alarming, but it confirms moisture is reaching the wall. Heavy efflorescence with flaking concrete suggests more significant water exposure.
Staining Patterns
Water stains with clear tide lines show where water has risen and fallen repeatedly. Dark staining in corners often indicates water entry from above (failed window wells, poor grading) rather than groundwater pressure. The pattern helps identify the source.
What Sarah's Report Actually Meant
After walking through her report together, Sarah realized her moisture findings fell into two categories. The crawlspace needed a vapor barrier and had some elevated readings that warranted monitoring - typical Portland stuff. But one corner of the basement showed active water intrusion during rain, with damaged drywall and mold growth behind it. That corner needed real attention.
She negotiated $3,500 from the seller to address the basement drainage problem. The crawlspace vapor barrier she planned to do herself for a few hundred dollars. The house was fine - she just needed to understand what the inspection was actually telling her.