We all have to start somewhere, if he has only recently joined ratedpeople then he may not have amassed any/many ratings. So maybe your best bet is to speak with him regarding the work and ask has he any references from previous jobs, or possibly a portfolio. If he has purchased a lead this will be possible as naturally he will call you to find out more information on the job and in order to quote you for it.
A few good questions should help you to grasp if he knows his area of work and you should help you pick up a general impression of him.
When tradespeople first join us, they won't have amassed reviews as we operate a closed-loop unique rating and review system. This means that tradespeople can't use past reviews and ratings from work sourced outside of our service. All homeowners like yourself will then know that the ratings and reviews on their profile pages are all genuine reviews from homeowners who have previously hired them through our site.
I would encourage you to take a good look at the rest of the tradespeople's profiles, looking at any photos they may have uploaded and any relevant qualifications/registrations with trade bodies etc. We have a homeowner checklist with more advice at ratedpeople(dot)com/c/homeowner-checklist.
I hope this helps!
The Ask an Expert Team