Bath; Weight Limits

I deliver to two private schools in the Monkton Combe area, and following the lorry routes in Bath, come across 7.5t limits. There is an approved route sign for Claverton Down (7.5t except for access) but follow it and you come to a 7.5t limit without an exemption on it. Is this typical Bath or is there a route I don’t know about? If I go through said limit there is no other restriction upto the school I’m delivering to.