On the ESM4118 list of particular occupations in the entertainment industry – TV and radio workers – behind the camera workers roles etc, normally treated as self-employed, (formerly “the Appendix 1 list”, a number of roles have an important qualification relating to the provision of equipment (the table generally refers to ESM0540 which can be seen here)
“If the engager provides any necessary equipment this fact will point towards the existence of a contract of employment…”
… but as is always the case with self-employment, it adds the following generic qualification:
“However, it is only one factor to be taken into account in the context of the overall picture and other factors must also be considered.”
The whole article is worth a look though – it provides a good grounding into the issue along with references to the key bits of legislation (Ready Mix Concrete, etc).