Re-roofing can be done one of two ways:
1. Your roof can be replaced entirely which involves removing the existing roof including slates, flashing, ridging, waterproofing materials, gutters, fascia, soffits, bargeboards, insulation and possibly rafters and replacing all the roof elements.
2. Your roof can be recovered leaving the underlying structure intact.
In most cases, re-roofing requires Building Regulations approval, especially if you live in a Conservation Area, which C Hanlon Roofing can help you with.