Roof cleaning equipment

The soft wash system is the defining piece of kit. It applies the cleaning solution at low pressure so the chemistry does the work over a 15-to-20 minute dwell, as ARMA describes, and then rinses thoroughly with low-pressure water. The important spec is not horsepower, it is reach and control — being able to treat the roof without walking on it.

The equipment that should not appear is a high-pressure wand on your shingles, and brushes or brooms. ARMA warns against both: pressure washing causes granule loss and very likely premature roof failure, and scrubbing loosens and removes granules through friction. If a crew arrives with a surface cleaner and a 3,000 PSI machine pointed at your roof, stop the job.

Access and fall protection matter as much as the sprayer. Given that NIOSH attributes roughly 40% of ladder-fall incidents to incorrect setup angle, stabilizers, proper ladder placement, and anchored fall protection are not optional professional niceties.

Preventive hardware means zinc or copper strips installed near the ridge. Malarkey notes these release metal ions that inhibit moss and algae growth, and that they are ideally installed during new roof installation rather than retrofitted. Malarkey's premium lines use at least a 10% copper granule blend in the shingle itself for algae resistance — a re-roof-time decision rather than an accessory.

How to choose

Ask what they will spray with, before booking

"Soft wash system, low pressure, no walking the roof" is the answer you want. Anything involving a pressure wand on shingles is not.

No brushes or brooms on shingles

ARMA warns that friction from scrubbing loosens and removes granules. Treatment plus dwell time plus gentle rinse is the method.

Zinc and copper strips work better on a new roof

Per Malarkey, they are ideally installed at new roof installation. A retrofit can help but is less effective and involves fastening into an existing roof — ask about penetrations.

Renting a pressure washer to do this yourself is the worst option

It combines the fall risk with the exact tool the manufacturers tell you never to use. This is the single most common way homeowners damage their own roofs.