Wind coming down the length of the lake hits the north-facing side of this city with nothing in the way. That shows up as wind-driven rain forced up under shingle courses, and as paint that fails on the north and west elevations years before the sheltered sides need attention. Anyone who has repainted a house near Lakeside Park knows the lake side goes first.
The housing stock is old, which is mostly a good thing and occasionally an expensive one. The neighborhoods running off Main Street and around the Division Street historic district are full of late-1800s and early-1900s homes: foursquares, gabled Victorians, real wood siding, deep overhangs and steep roof pitches. Prep that original wood siding right and it holds paint for a decade. Skip the prep and it peels in two summers.
Those same houses tend to have modest attic insulation and blocked soffit vents, which is the recipe for ice dams. A large share of what gets called a roof leak in Fond du Lac in February is meltwater backing up behind ice at the eave, and it is not fixed by more sealant.