We had a contractor build us a pole barn which he drug out over 10 weeks. He just put the metal siding up and the screws holding the siding on are going in at an angle because the 2x4's and the holes weren't lined up in spots. The hole is essentially a little above the 2x4 and the screw wouldn't bite in so they drilled it in at an angle. In some of the spots i can see a bit of daylight. I haven't paid him in full yet, what should i expect as far as craftsmanship in putting on siding and what should i expect as far as recourse here?