While you write 'My manager says mine is not good enough', you then list a host of environmental and task variables whose hazards can be identified and controlled. Two possible ways ahead include a. the manager has identified task or environmental hazards, which he hasn't told you about (maybe you didn't ask him or her?) b. the manager has a hunch that personal variables are sources of hazards, e.g. fatigue, stress, a physical or mental disability and expects you to conduct the reseearch necessary to identify and measure them so that they can be appropriately controlled. Either way, a conversation with the manager is necessary. In the case of (a), the hazard control stage may then be straightforward; in the case of (b), you may well need assistance from an ergonomist and/or psychologist unless the manager is content for the alleged 'risk' to remain an uncontrolled residual

Is this really working at heights??? This is a genuine question as I do not work in H&S (fire safety). I am a bit shocked that such an everyday low risk task could attract a WAH label