Corrugated Metal Roofing

Corrugated Metal Roofing

Product Warranty:

The corrugated panel carries a 30-year corrosion warranty on aluminum.

Corrugated Metal Panel Installation & Care:

Building Design and Construction

In order to ensure adequate performance of this product, protect metal panels from potentially corrosive situations and materials. In situations where treated lumber will be in direct contact with metal panels please keep in mind the following: Galvanized steel is compatible with the CCA (Chromated Copper Arsenate) pressure-treated lumber that is predominantly used today, but not with the older Penta treated lumber. Aluminum, however, must be separated from contact with all treated wood since the chemical preservatives are corrosive to aluminum. Likewise, dissimilar metals also require a protective barrier between them to prevent galvanic corrosion.

When using aluminum panels in direct contact with steel, use one of the following methods to separate the two metals: Felt, plastic, bituminous paint, gasket material or caulking.

Contact between metal panels and any potentially corrosive materials should be prevented. The following substances are a small example of substances that can cause corrosion in metal panels: Fertilizer, lime, acids, feeds, manure, soils, etc.

Porous insulation board may absorb and retain moisture, and requires a vapor barrier similar to that described above. This vapor barrier should be installed such that moisture is prevented from contacting both the insulation and the metal panel.

Purlins, Girts and Roof Deck

The material to which the metal panel is fastened should be properly spaced and sufficiently thick to provide a roof or wall system able to meet required design loads. Load tables are available for all of our panels. We recommend spacing the purlins a maximum of 24 on-center for roofing (note that 5V requires solid decking).

In re-roofing jobs where the condition of the old decking is in question, or where existing shingles will be left in place, new 24 purlins should be fastened through the decking and into the rafters. This will provide a solid framework for attaching the metal panels.

Since sidelaps should face away from wind driven rain, begin installation by installing the first panel square with the eave and gable at the downwind end of the roof, farthest away from the direction of local prevailing winds.

To provide a drip edge, allow an overhang of 1 to 2 at the eave. At the gable edge, use a gable or sidewall flashing. This will keep weather out, prevent lifting in high winds, and provide a neat, finished appearance. The trim and roofing sheet should be fastened every 6 to 10 inches along the gable edge.

Roof Pitch

The metal corrugated panels require a minimum pitch of 2-1/2 per foot to ensure proper drainage. For wider buildings and lower roof pitches, contact us for other suitable metal panel styles.

Fastening Your Metal Panels

Absolute Steel can supply either screws or nails for fastening into dimension lumber, with screws being the preferred method of attachment. Woodgrip screws for use with steel panels are galvanized and then coated with an organic polymer for optimum corrosion resistance. For best results with aluminum panels, use #300 series stainless steel Woodgrip screws.

If using nails, please note that the correct way to fasten steel panels with nails is to drive the nail through the top of the rib so the washer is compressed securely against the metal. Nail placement must be in the ribs for roofing projects to minimize the potential for roof leaks. Be careful over-driving the nail can split the washer and dimple the metal, causing leaks.

Wood screws with combination metal and neoprene washers should be installed in the flat area of the panel adjacent to the ribs, and tightened such that the washer is compressed as illustrated above. This will ensure a lasting, leak-proof seal.

Metal Roof Maintenance

A metal roof should be inspected annually and cleaned as necessary to maintain its beauty and performance. Any debris or residue, including leaves, twigs, and dust should be cleaned off promptly to prevent moisture entrapment against the metal, which may lead to finish deterioration or premature corrosion.


Leave a Reply