Roofer proves two layers of paper will not save you if your have low ball construction roofing your house. The biggest myth in roofing is that you need two layers of felt paper. Wrong! I’ll take one layer installed properly.
We fix all kinds of roofs but, mostly we fix concrete tile roofs.
Newer concrete tile roofs “usually” have a double felt and that is not a bad thing. But, if your roofer sucks two layers will not keep your roof from leaking much sooner than it should.
Their seems to be a never ending supply of leaking roofs that were poorly done here in southern CA. I would estimate about half the roof I fix leak from improper installation. Your roof should only leak from wear and tear.
It’s unfortunate but, you get what you pay for. Hopefully.