The following websites may be of interest to you:
The National Roof Training Group is the representative body for the UK Independent Roof Training Groups.
The National Federation of Roofing Contractors is the UK's largest roofing trade association, representing over 70% of the roofing industry by value.
The Institute of Roofing is the only organisation in the UK awarding professional qualifications in the roofing industry.
The Industry Training Board and a partner in the Sector Skills Council for the construction industry, working with industry, for industry to deliver a safe, professional and fully qualified UK construction workforce.
Training & Apprenticeship Providers for Roofing - a free online resourse to upload and search for roof training provision throught the UK.