Pressure washing in Woodbridge, Connecticut.

Local conditions

The most wooded town on the list.

Woodbridge covers 19.2 square miles, of which under half a square mile is water. It is hilly, it sits at about 350 feet of elevation, and the town describes itself as rural in feel, with single family homes on lots of an acre and a half or more and an extensive network of preserved open land and trails.

For exterior cleaning that adds up to one thing: shade. Houses on large wooded lots sit under mature canopy for most of the day, and surfaces that never dry out properly grow things. Roofs here collect moss and lichen rather than just algae streaking, and moss holds water against the shingle, which is a different and slower kind of damage than dirt.

The gutters follow the same logic. Our general recommendation is clearing them at least twice a year, spring and autumn, and we say plainly that properties with heavy tree coverage need it more often. Woodbridge is the town where that sentence stops being a caveat and becomes the default.