Steelwise operates on the basis that a roof is a rectangle or collection of rectangles (also referred to as roof blocks). Roof blocks can merge, overlap, or contain more than four sides. Identifying roof blocks helps you create accurate truss layouts.
Identifying roof blocks
The simplest approach is to look for the largest identifiable roof block in an architect's plan, then look for the smaller blocks that connect to it.
Simple roof example
A roof that has a single pitch can be treated as one roof block. All roof lines for a roof with a single pitch will be at right angles to one another.
More complex examples
This more complex roof consists of four roof blocks.
The example below shows a good example of a complex roof. Note the overlap of the two roof blocks. Generally, when you have an overlap of roof blocks, you have a complex roof. The larger the overlap, the more complex the roof.
Note the direction of fall. On each occasion the roof MUST fall to a valley or gutter.
