Explanation:

When designing a roof truss, there are different components that make up the structure. These components include the truss itself, the purlins, and the roofing material. The cost of each of these components will vary depending on a number of factors, including the size of the roof, the materials used, and the complexity of the design.

In order to minimize the total cost of the roof, it is important to find the right balance between the cost of the truss and the cost of the purlins. The ratio of the cost of the truss to the cost of the purlins can help to determine this balance.

Ratio of cost of truss to cost of purlins:

The ratio of the cost of the truss to the cost of the purlins is an important factor in minimizing the total cost of the roof. This ratio can be expressed as a simple mathematical equation:

Ratio = Cost of Truss / Cost of Purlins

By finding the right ratio between these two costs, it is possible to minimize the total cost of the roof without compromising on the structural integrity or safety of the structure.

Optimum ratio:

The optimum ratio of the cost of truss to the cost of purlins will depend on a number of factors, including the size of the roof, the materials used, and the design of the truss. However, in general, a ratio of 2:1 is often considered to be a good balance between the cost of the truss and the cost of the purlins.

This means that the cost of the truss should be approximately twice the cost of the purlins in order to minimize the total cost of the roof. By achieving this balance, it is possible to ensure that the roof is structurally sound and safe, while also keeping costs as low as possible.

Conclusion:

In conclusion, the ratio of the cost of the truss to the cost of the purlins is an important factor in minimizing the total cost of a roof. By finding the right balance between these two costs, it is possible to ensure that the roof is safe and structurally sound, while also keeping costs as low as possible. A ratio of 2:1 is often considered to be a good balance, although this may vary depending on the specific design and materials used.