Dimples or protrusions

I have 50+ dimples/protrusions that poke up on the underside of my Galvalume, 24 gauge, hidden fastener metal roof. These protrusions line up with the 1x4 furring strips my installer used.

The installer brought the representative from the metal company to look at the roof. After asking for a direct answer, he said that unless they know what's causing these dimples the warrantee is not voided. But IF it is a metal fastener then the warrantee would be voided on the roof. To me it's plain as day these protrusions are from nails that are not flush with surface of the wood. The installer say's it's cosmetic?

The warrantee states " Deterioration to the panels caused directly or indirectly from panel contact with unsuitable fasteners or sealants" voids the warrantee.

Researching about thermal expansion, metal roofs expands & contracts with heating & cooling. That's why they have slots where the fasteners area secured, to allow for that movement. Eventually these stationary nails will rub the protective coating from the underside and eventually rust / break the surface.

I feel that these dimples/protrusions are on the installer to repair before final payment is made.

Is it correct to feel that these protrusions are a issue that needs to be fixed, prior to final payment? It voids the warrantee, and will eventually cause rust or penetrate the roof.

Hey Todd, these protrusions follow the furring strips and the protrusions are equal distance's +/- 3 inches between them. When the furring strips where installed they used a nail gun. Between the furring strips is Styrofoam and that's where the pancake screws are securing the panels at. So let's assume these are nails or something of a hardness that can dent 24 gauge steel.

The issue is this roof is suppose to last 40-50 years. I don't see these protrusions going away, if anything more will occur. I agree oil canning is cosmetic because the panels aren't damaged or permanently distorted.

Would it be proper workmen ship, when installing a metal roof, to ensure that all nails are flush/below the surface of wood?

If these are nails, over time with thermal expansion/contraction, won't rust form?

Once rust is bad enough won't a hole develop?

I'm trying to get peace of mind today, instead of waiting 15 years and then trying to get the issue fixed. If there were one or two of these protrusions I'd gamble with it, but with 50+. I just don't feel it's proper workmanship. Especially when the installer stated that this is something that was caused by him.