Student Question Roofing Underlayment Offset

The end-laps of the underlayment should be offset by at least 6 feet.

Can someone lend some clarity to what this means. I copied this sentence from standard 3 # of roofing underlayment
Ref: 25 Standards Every Inspector Should Know Course

They are referring to the staggering of the multiple rows of underpayment in case water gets under the covering layer and runs down the underlayment, look at this pic:


Thank you- 6 feet max then the underlayment should have an adhesive.

6’ MINIMUM :smile: