Illinois Roofing Practice Exam 2026 - Free Roofing License Practice Questions and Study Guide

Blocked rafters play a crucial role in maintaining the structural integrity of a roof system. Their primary purpose is to prevent rafters from twisting or deforming over time, especially under load or environmental stresses. When rafters are blocked, they are effectively braced against each other, which helps to stabilize them and maintain their alignment. This is particularly important in ensuring the long-term durability of the roof structure.

While enhancing ventilation, supporting additional roofing layers, or providing a space for insulation are all relevant features in roofing systems, they do not specifically address the primary function of blocked rafters. Properly blocking rafters is essential to reduce the likelihood of structural failure and is a standard practice in roofing to ensure stability.