I will be running a 22mm plastic heating pipe horizontally through a cavity wall (inside of garage to under floorboards in living room) and need to know what width and length drill bit to buy for the job. Its my understanding that the piping will need some type of sleeve around it to protect it against rub of the bricks so the width will also need to accommodate the sleeving. Can anyone recommend a good sleeving too. Thanks. ps, I will be using a SDS drill with a clutch before anyone asks as I don't want to end up in hospital!