Birchwood sits on Bellingham's northwest side, a neighborhood of ranches, split-levels, and modest two-stories mostly built between the 1950s and 1970s along the streets between Squalicum Creek and Northwest Avenue. Homes of that era were commonly sided in cedar, plywood T1-11, or hardboard lap, and after five or six decades of Pacific Northwest weather, a lot of that original cladding is at the end of the road.
How Birchwood Siding Wears Out
The failure pattern here is familiar to us. Wind off Bellingham Bay drives rain against west- and south-facing walls all winter, and anywhere the paint film has cracked, water gets behind it. Hardboard siding from the 60s and 70s swells at the bottom edges and around nail heads once moisture reaches the core. T1-11 delaminates at the grooves. Cedar holds up better but still rots first at the classic trouble spots: behind downspouts, under window corners, around hose bibs, and along the bottom courses where splashback keeps the wood wet.
Low winter sun and the damp air near Squalicum Creek also mean north walls in Birchwood grow green algae film almost universally. That is cosmetic on sound siding but a warning sign on failing material, because the same conditions that grow algae keep compromised siding from ever drying out.