Roof cleaning checklists

Vetting. Ask three questions and listen for hesitation. What method will you use on my asphalt shingles? What fall protection does your crew use? Can your insurance agency send me the certificate directly? ARMA's guidance that a pressure washer should never be used on asphalt shingles gives you a clear pass/fail on the first one.

Quote stage. Require the method named in writing, the roof area they measured (not house square footage), moss removal as a distinct line if applicable, landscape protection, and whether gutter clearing is included. Sanity-check the total against Today's Homeowner's $255-$1,190 typical range and $0.15-$0.70 per square foot — a quote far under that usually means high pressure or no insurance.

Before work starts. Move patio furniture and vehicles. Confirm they will pre-wet and rinse landscaping — ARMA advises protecting landscaping and surrounding areas from the bleach solution. Close windows. Take before photos of the roof from the ground on every elevation, plus the gutters and downspout outlets.

Before you pay. Look in the gutters and at the downspout outlet for granules — ARMA warns that pressure washing and scrubbing both cause granule loss, and that is where the evidence lands. Check plants under the eaves. Compare against your before photos. Ask what the contractor expects the roof to look like in 12 months, and hold them to it.

How to choose

Insurance certificate direct from the agency

General liability and workers' compensation. A PDF forwarded by the contractor is easy to edit; a certificate emailed by the insurer is not.

Get the word "soft wash" in the contract

Plus an explicit statement that no high-pressure equipment will be used on the roof surface. That single line is your leverage if granules end up in the gutters.

Photograph everything before they arrive

Every roof elevation, the gutters, the downspout outlets, and the landscaping. Ten minutes now settles any dispute later.

Confirm who handles the runoff

Pre-wetting plants, tarping, and rinsing after should be named in the scope, not assumed. ARMA advises protecting landscaping and surrounding areas.

Ask what results they promise, and for how long

An honest contractor will say regrowth is expected. ARMA states results are only temporary. A permanence promise is a reason to walk.