Pressure washing is one of the most common methods for roof cleaning. Unfortunately, it can be the most damaging. A tile roof, for example, is not waterproof on its surface. The tile is designed to shed water, while the underlayment and flashings do the real work of keeping the building dry.
When you pressure wash a roof, you force water up and under the tile system in ways it was never designed to handle. Add in chlorine or bleach-based solutions, and you are pushing harsh chemicals directly onto the fasteners, underlayment, drip edges, and other metal components that hold the roof together.
The impact of this damage may not be immediate, but it is cumulative. Every time those chemicals are introduced, another layer of corrosion or deterioration sets in. A roof expected to last 25 years can quickly become a 19-year roof. That difference translates directly into special assessments and budget shortfalls that could have been avoided with proper maintenance practices.
Even worse, many manufacturers and roofing contractors require ongoing maintenance to uphold warranties. If the source of damage can be traced back to improper cleaning or negligence, warranty claims may be denied. This leaves the association covering the bulk of repairs that might have, with appropriate maintenance and record keeping, been covered by insurance. It's also worthwhile to note that damages caused by other trades on your roof will likely not be covered under your warranty.
The good news is that not all roof cleaning is harmful. Products such as Citra-Shield™ and Roof-A-Cide® are designed specifically for condominium roof maintenance. They use safe, non-chlorine solutions that prevent mold and mildew growth without damaging roofing systems.
The difference between cutting corners and using the right products can mean years of roof performance and millions in avoided costs across a community. Property managers and boards who choose roof maintenance programs built around safe products are not just protecting their roofs, they are protecting their financial stability.