Do you advertise this service ? ie: roof cleaning and gutter cleaning ? If no then why consider taking it on ?
The very fact that you've posted such a question on here suggests to me that you should pass on it. Sorry if that sounds blunt and unhelpful..........................
...................Now I will go on to say I was asked a few years back to do a very similar job for somebody. I'd get shot down on here for endorsing it and suggesting you do the same as me . I'll just say it involved a ladder, some rope and a yard broom
Although all went well and did a good job - I'd not do it again. There are specialist companies out there with the tools and chems ( if needed ) for the job and the specific insurance.( as well as other numpties like my previous self keen to do it for next to bugger all hey
Smurf ?
)