Hi Daniel, before you go off half-cock what sort of duct is it i.e is it moving air or grease from a kitchen? If it's just an air duct use a compressor and vacuum if it's from a DFF you're wasting your time and need to simply fit access panels so you can manually reach into the duct and scrape / steam it clean.
Your're out in the NW in tourist land so I assume ( ass of u and me?) that this is a one-off enquiry you think has potential as a market? Just think of the time and energy you are putting in / will input as unless it's really important that you personally sort it, I think you should just tell your customer you will find someone who specialises in that sort of work and pass the problem onto someone else who does Vent and Duct cleaning. If your on the ball arrange it all and add a % on for your hassle. Cost wise expect a bill of £10 / metre for cleaning plus £50 quid for supplying and fitting an access hatch.
Phil D
Poll