How to Overlap Corrugated Metal Roofing

How to Overlap Corrugated Metal Roofing

Installing corrugated metal roofing efficiently and correctly can significantly impact the durability and waterproofing of a structure. 

Overlapping these sheets is a crucial aspect of the installation process. 

This article will guide you through the steps to properly overlap corrugated metal roofing.

Understanding the Basics of Corrugated Metal Roofing

What is Corrugated Metal Roofing?

Corrugated metal roofing is a type of roofing material known for its durability, longevity, and weather resistance. 

It consists of metal sheets with a wavy pattern, which adds strength and rigidity. Common materials include galvanized steel, aluminum, and sometimes copper.

Why is Proper Overlapping Important?

Overlapping corrugated metal sheets correctly is essential for several reasons:

  • Waterproofing: Proper overlap prevents water seepage.
  • Wind Resistance: Correctly overlapped sheets can withstand high winds.
  • Longevity: It ensures the roof’s long-term durability.

Step-by-Step Guide to Overlapping Corrugated Metal Roofing

Tools and Materials Needed

  • Corrugated metal sheets
  • Tape measure
  • Marker
  • Metal snips
  • Screws and a screw gun
  • Ladder
  • Safety equipment (gloves, goggles, etc.)

Step 1: Preparing the Roof

  1. Clean the Area: Ensure the roof surface is clean and flat.
  2. Safety First: Use a ladder safely and wear protective gear.

Step 2: Measuring and Marking

  1. Measure the Roof: Determine the length and width of the area to be covered.
  2. Mark the Sheets: Mark the overlap area on the metal sheets using a marker.

Step 3: Cutting the Sheets

  1. Cut if Necessary: Use metal snips to cut the sheets to size.
  2. Smooth Edges: Ensure the cut edges are smooth to avoid injury and improve fit.

Step 4: Laying the First Sheet

  1. Positioning: Place the first sheet, ensuring it’s straight and aligned.
  2. Secure the Sheet: Fasten the sheet using screws, starting from the top.

Step 5: Overlapping the Sheets

  1. Overlap Amount: Overlap the next sheet by at least one corrugation more in areas with high winds or heavy rainfall.
  2. Alignment: Ensure the sheets are perfectly aligned for a uniform look.
  3. Fastening: Secure the overlapped area with screws, spaced evenly.

Step 6: Continuing the Process

  1. Repeat: Continue laying and overlapping the sheets.
  2. Check Alignment: Regularly check that the sheets are aligned and flat.

Step 7: Finishing Touches

  1. Trim Excess: Trim any excess material at the edges.
  2. Seal Edges: Apply a sealant along the edges for extra waterproofing.

Common Mistakes to Avoid

  • Incorrect Overlap: Overlapping too little can lead to leaks.
  • Misalignment: Sheets must be aligned precisely for effective coverage.
  • Inadequate Fastening: Ensure each sheet is securely fastened.


  1. How much should I overlap corrugated metal sheets? Typically, overlaps by at least one corrugation, but this can vary based on weather conditions.
  2. Can I cut corrugated metal sheets myself? Yes, you can cut these sheets with the right tools, like metal snips.
  3. Do I need professional help to install corrugated metal roofing? While it’s possible to do it yourself, professional assistance is recommended for larger or more complex projects.


Overlapping corrugated metal roofing correctly is key to a successful installation. By following these steps, you can ensure your roof is durable, weather-resistant, and long-lasting. 

Safety is paramount, so take the necessary precautions when working at heights.

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