Do-It-Yourself Metal Roof Installation

Metal may be the most versatile roofing material. Once mainly available in corrugated or ribbed panels, today it can be had in panels resembling tile, slate, terracotta, cedar shakes or asphalt shingles. It also is available in many corrugated versions, some with wide flat valleys in a style called standing rib, which is popular in many ski resort communities because of its ability to shed snow. Install metal roofing over existing roofing, on new wood decking or on 1-by-4-inch boards nailed across rafters, called strip sheathing or purlins. Installation techniques are similar for all styles.

Things You'll Need

• Tape measure
• Tin snips or metal saw
• Metal roofing panels
• Underlayment
• Closure strips and metal flashing
• Screw gun
• Special metal roofing screws with washer heads

Instructions

1. Measure the roof area with a tape measure to determine the number of panels needed. Determine the coverage area for each panel, generally 24 or 36 inches, although panels are wider to allow for overlaps. Choose an appropriate width and length, depending on the style you select; panels come in 8 to 16 foot lengths and may be cut to size with tin snips or a metal saw.

2. Check the installation area. Ensure existing roofing or decking is clean, free of all debris and has no nails or nail heads sticking out. Put asphalt or similar underlayment and moisture barrier on existing roofs or decking and on purlins if they are over a heated space; add insulation under the purlins before installing metal roofing.

3. Install edging material, metal flashing or drip edge where roof lines end or meet walls, rubberized closure strips where metal roofing meets flat surfaces. Closure strips are available to match the ribs and valleys of the metal roofing panels, to seal edges against moisture. Put these or flashing at all edges, valleys and peaks on the roof, to form a water-tight barrier when you add roof panels.

4. Verify the roof is square; if it is not, panels will not line up properly. Begin installing panels at the bottom left corner of the roof, using a screw gun to drive in special screws with a hexagonal head and a neoprene washer built in at the head. Use self-tapping and drilling screws when installing metal to metal. Use similar screws for purlins; these do not have a sharp drilling point and require drilling through the metal panel. All screw types are available in various lengths to fit all installation needs.

5. Add the second panel above the first, overlapping it by 6 inches. Put the third panel beside the first one, overlapping edges by one rib and valley or according to manufacturer's recommendations; overlaps will vary with roofing styles. Screw overlaps together on both sides. Add self-tapping "lap stitch" screws on the top of the overlapped rib to hold panels together; avoid blocking any drainage channel built into the overlap.

6. Continue adding panels in the bottom to top and side to side pattern until you cover the roof. Complete the roof by screwing roof caps on all peaks and adding fascia flashing strips under the roofing and down over the edge facing. Roof caps are shorter v-shaped panels that overlap the roof line on both sides of the peak to seal it.

Tips & Warnings

• Get help. Roofing panels are not heavy but are unwieldy.

• Use caution on a roof and never work in wet or windy conditions.Metal roofing becomes very slick when wet.

• Use gloves when handling panels to protect against sharp edges

• Wear protective eyewear when cutting or drilling metal panels.

References

• Mechanical Metals: Corrugated metal roofing
• Metal Roofing Source: Popular metal roofing
• Ask the Builder: Metal roofing
• Metal Roofing: Roofing styles

Resources

• Read this Article in Spanish
• Best Buy Metals: Metal roofing types