Final answer:
Wood shakes should not be installed on slopes less than 3:12, as flatter slopes can cause water infiltration and damage to the roof.
Step-by-step explanation:
The student is asking about the minimum slope required for the installation of wood shakes on a roof. In the roofing industry, it is recognized that wood shakes should not be installed on slopes that are flatter than 3:12 (three inches of vertical rise for every twelve inches of horizontal run). Installing them on flatter slopes can lead to water infiltration and reduced longevity of the roof.
Therefore, the answer to the question 'Wood shakes shall not be installed on slopes less than __________.' is 3:12. It is essential to follow proper roofing guidelines and building codes to ensure the integrity and safety of roofing installations. Wood shakes should not be installed on slopes less than 3:12, as flatter slopes can cause water infiltration and damage to the roof.