mont

We've had our guttering and facias replaced, and the roofer has used a plastic sheet materiel under the tiles and protruding about 50 mm down into the gutter, it's a neat job, but the wind is flapping this and making an annoying banging sound. He had to scaffold over our conservatory to do this job, so unsuprisingly he's not interested in coming back to sort this problem out. So is this overhanging sheet good roofing practice, or does it need to go ?