In the application of corrugated sheet metal roofing, how many corrugations should be included in the side laps?

In corrugated sheet metal roofing applications, including additional corrugations in the side laps is essential for ensuring proper water shedding and wind resistance. A side lap that comprises one and a half corrugations is optimal. This count provides a balance between sufficient coverage to prevent leaks and allowing for the necessary expansion and contraction of the metal due to temperature changes.

Using one and a half corrugations helps ensure that the overlap is substantial enough to effectively direct water off the roof surface while maintaining structural integrity. It reduces the risk of water infiltrating beneath the sheets, especially during heavy rains or storms. Additionally, this configuration aids in aligning the sheets correctly during installation, ultimately leading to a more secure and weather-tight application.

The other answers represent insufficient or excessive overlaps, which could compromise the roof's effectiveness against water intrusion or put undue stress on the materials during environmental changes. Therefore, including one and a half corrugations in the side laps is the best practice for achieving a durable and reliable roofing system.