Residential Sheet Metal Is Considered To Be What Gauge

The problem with metal roofing gauge is that there is a wide range of tolerances.

Residential sheet metal is considered to be what gauge.

The gauge of a metal roof refers to its thickness and the higher the gauge the thinner the metal. This is known as the manufacturers standard gage for sheet steel. For 18 ga crs the weight is 2 0 pounds per square foot. The gauge number 18 holds no relevance to the actual measurements.

16 ga crs is 2 5 pounds per square foot. The american iron and steel institute aisi publishes the accepted measurement standards for steel thickness. For example 18 gauge steel according to a gauge conversion chart is 0 0478 inch or 1 214 millimeter. For other materials such as aluminum and brass the thicknesses will be different.

The equivalent thicknesses differ for each gauge size standard which were developed based on the weight of the sheet for a given material. Gauge to thickness chart gauge stainless galvanized sheet steel aluminum fraction inches mm inches mm inches mm inches mm 30 0 0125 0 33 0 0157 0 40 0 0120 0 30 0 0100 0 25. Sheet metal thickness gauges for steel are based on a weight of 41 82 pounds per square foot per inch of thickness. Thus a 10 gauge steel sheet which has a thickness of 0 1345 inches will weigh 41 82 0 1345 5 625 pounds per square foot.

For example one company might sell a product as being 24 gauge but in reality the thickness of the metal could vary from 0 018 to 0 0335 based upon exactly how that company looks at things and how big of a tolerance they allow for. 28 gauge steel has an average thickness of 0187 minimum 0157 and 26 gauge is 0217 minimum 0187. For example standard 29 gauge steel roofing made in long panels is about 0 36 millimeters thick and the 26 gauge version is slightly thicker at 0 48 millimeters. All our fabricated duct is 24 26 gauge.

Some steel shingles and tiles have a baked on granular coating that adds to their thickness and the mra notes that those products are usually made from 26 gauge steel. 26 gauge steel structures are most likely an all steel building structural steel frames and widely spaced steel roof purlins. Gauge or gage sizes are numbers that indicate the thickness of a piece of sheet metal with a higher number referring to a thinner sheet. I have been building designing and installing residential sheet metal duct systems for over 40 years and not once in those 40 some years has one local or state inspector called me or any other mechanical contractor i know and it s dozens on using 30 gauge galvanized piping for branch runs.

Any plenums square duct over 12x12x12 should be a heavier gauge than 30 even when cross broken they tend to have duct banging issues because the metal isn t rigid enough imo.