Downtown Bellingham is two roofing worlds sharing a few square blocks. Above the storefronts along Holly, Cornwall, and Railroad Avenue sit low-slope roofs — membranes, drains, and parapets on buildings that in some cases predate the First World War. A few streets out, in the Lettered Streets and York neighborhoods that ring the core, the housing turns to steep-pitched homes from the early 1900s. We roof both, and they fail in completely different ways.
Low-Slope Roofs: Drainage Is Everything
A flat roof in a city that gets close to three feet of rain a year is really a very shallow pool with a schedule. When the drains, scuppers, and slope-to-drain details work, a modern TPO or torch-down membrane performs for decades. When they clog or were never right, water ponds, seams stress, and the leak shows up two rooms away from its source — usually above someone's inventory or tenant. Our low-slope work downtown focuses on the details that actually decide lifespan: tapered insulation to kill ponding, properly flashed parapets and penetrations, and walk pads where HVAC techs actually walk.
Older masonry buildings near Whatcom Creek and the Maritime Heritage Park end of downtown add their own wrinkle — brick parapets that wick moisture and flashing embedded in mortar joints that gave up decades ago. We rebuild those transitions correctly rather than smearing another generation of roof cement over them.