This InterNACHI course material on roof inspections focuses on ladder safety, specifically outlining different ladder types and providing instructions for safe set-up and use. The text emphasizes the importance of using a three-point control method for climbing, which involves maintaining a stable grip on the ladder rungs with two hands and one foot, or two feet and one hand, at all times. The text also highlights the need to secure ladders properly to avoid falls and to avoid using vertical rails, which offer less support than horizontal rungs. The material concludes with practical tips for determining safe ladder placement and choosing ladders that meet weight requirements.