Get it from Jandi, it's only .50p a metre and it's better quality than from elsewhere. I have just done around the gas door, along the bottom of the sides and across the front. I haven't done around the door yet, I suppose I'll have to remove the door,which is easy enough, it just lifts off the hinges, then remove a hinge in turn ensuring I put them back exactly in the same place, to get behind the hinges and insert the new strip. I did mine on a hot day , if it's cool soak it in hot water first to soften it. I also sprayed in the gap some wd40 which made it easier to get in, I don't think I would use any "roofers mate" or similar. The herzim strip is only there to hide the screws.