I was asked the following question:
I am looking at samples of several roofing products. Two of them claim to be 26 gauge, but they feel very different. One is clearly lighter than the other. Can I use a micrometer to test the thickness and figure out which one really is 26 gauge? Is there a chart that would tell me the appropriate thickness for the 29, 26 and 24 gauge of roofing materials? Please review and advise. This is very important to me.
As long as you gauge a flat area of metal, sure you can check it with micrometers.
I have long been a proponent of the industry looking at steel roofing in terms of decimal thickness rather than gauge.
Too many games can be played with gauge in regards to tolerances, with paint, without paint, etc.
You can find charts referencing gauge and decimal thickness but as you will see there is a wide range of tolerance on decimal thickness for each gauge.