Stop treating access routes as simple tarmacadam jobs. You need to hit Part M...

https://kylerigdr519.lucialpiazzale.com/do-older-office-blocks-need-to-meet-current-access-standards-after-small-changes

Stop treating access routes as simple tarmacadam jobs. You need to hit Part M regs and test to BS 7976 for slip resistance. Don't skip vetting your crew; use CHAS to ensure quality. It saves you from future liability and expensive rework.