Yes a clean roof massively boosts curb appeal. Firstly it’s one of the first things someone will notice on your home as it typically accounts for up to 25-40% of what they see as they approach your house. A clean roof signals overall good home health and maintenance compared to a dirty, moss-covered roof indicates lack of maintenance and potential underlying issues. And most importantly a clean roof can help increase the perceived value of your home leading to an increase in sale price, studies found that good curb appeal can increase the asking price of a home by 5-10%.