CU sheet metal thickness equivalent to AL

[Mike Lamb]

When installing an open valley, use 16 oz. copper flashing at a

minimum (or its equivalent) over WinterGuard? Waterproofing

Shingle Underlayment (or its equivalent). Preformed ?W? style

valleys are preferred (Figures 16-11 and 16-12).

The aluminum used on this valley looks like typical .0145 coil stock. What is the equivalent AL to 16 oz. CU?

This is a Certainteed Grand Manor Shangle roof. There are so many problems on this job that the valley issues are just piling on. I am very aware of the underlayment issues. The builder is not going to be happy with what his roofers did and did not do.

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[Marc]

It's an error in choice of unit of measure.

Where'd you see this?

Marc

[Mike Lamb]

It's from the Grand Manor installation instructions.

http://www.certainteed.com/resources/Gr ... nstall.pdf

[Marc]

The writer probably meant 16 gauge, which is 50/1000 of an inch when the material is copper. A primer on copper sheet metal gauge

Marc

[Bill Kibbel]

Ounces is the proper measurement for copper sheet. I think that it means 16 oz. copper = one square foot weighs 16 ounces. This translates to .0216" or 23 gauge.

[Tom Raymond]

Wow. When they cheap out on an application of that price point here they use steel flashings and drip edges.

That's a shame.

[kevinbrown10]

I agree with Bill that ounce is the proper unit of measuring the thickness of copper sheets and it can be easily converted to gauge the more popular unit.