I'm repairing some rotting windows & want something to put over the
dodgy bits in case it rains while I'm re-doing them. I thought I'd
use Duct tape, but went to my local hardware store & they only had
Gaffa tape - is that the same thing? Are they both waterproof?

Also my local Homebase doesn't sell Duct tape but does sell something
called Duck tape (which looks very similar). Is it just a
manufacturers brand name?

Thanks,

Michael