Roof cleaning safety

The fall risk is the one people underestimate. CDC/NIOSH reports more than 100 deaths a year in the US from ladder-related falls, with thousands more injured, and identifies incorrect extension ladder setup angle as the cause in roughly 40% of incidents. Overreaching and carrying objects are also leading causes — which is exactly what roof cleaning involves. A roof wet with cleaning solution is significantly more slippery than a dry one.

The chemistry is not benign either. ARMA's recommended approach uses a 50:50 mix of laundry-strength liquid chlorine bleach and water, and advises using appropriate personal protective equipment when working with chlorine bleach. That means eye protection and gloves at minimum. Bleach mist blowing back into your face on a roof edge is a genuinely bad situation.

Then there is what the runoff does. ARMA advises taking proper precautions to protect landscaping and surrounding areas from the chlorine bleach solution. Plants under the eaves die readily. Professionals pre-wet and rinse landscaping and tarp what they can — ask specifically whether that is in your quote.

Manufacturer guidance from Malarkey makes the same point about competence: roof work requires proper training and equipment because of the safety hazards. If your instinct is that this looks manageable with a ladder and a garden sprayer, that instinct is the risk.

How to choose

Do not walk a wet roof

Cleaning solution makes shingles slick, and walking a wet roof also grinds granules off. Professionals work from ladders, from the ground with extension equipment, or with fall protection.

Verify insurance from the insurer

Ask for a certificate of liability and workers' compensation insurance sent directly by the insurance agency. If an uninsured worker falls on your property, that can become your problem.

Ask what fall protection they use

A crew that cannot answer this question is a crew that does not use any. That should end the conversation.

Protect the landscaping before work starts

Pre-wetting plants, tarping, and rinsing after are standard. ARMA explicitly advises protecting landscaping and surrounding areas from the bleach solution.

Never mix cleaning products

Chlorine bleach mixed with ammonia or acidic cleaners produces toxic gas. If you are on the roof improvising chemistry, stop.