Every year or 2, I buy a bulk quantity of water softener salt. I always get 25kg bags and I buy 20-40 bags in order to get them at the best price.
I'm then left with a problem. I have space to store them in my attic room (where they need to be, alongside the water softener), but that means I have to transport all of the bags up a flight of stairs (just one, thankfully), to the attic room.
Carrying just one of them by hand is just about doable; doing it 20-40 times is impossible.
I've considered some form of winch, but any permanent/expensive equipment is overkill given the fact that it will only be used every year or 2.
Any ideas for how to move them without back-breaking effort?
Yes, smaller bags would work, yes a smaller quantity would work but both would cost more money. Opening the bags and dividing them is impractical because I would have to reseal them all afterwards. Leaving them downstairs and spreading the work is also a non-starter due to space constraints.
EDIT: although a diagram is overkill, here is a description of the "landscape" within which this needs to take place: 1) the stairs are a straight, single flight of 13 steps, 2) there is a large area of clear floor-space at the bottom of the stairs within which to work, 3) there is a doorway about 1 metre opposite the top of the stairs i.e. useful for bracing a pulley mechanism against, 4) this gives about 5 metres of working space at the top of the stairs, 5) the ceiling above the stairs follows the slope of the stairs from bottom to top, 6) the stairs are carpeted but 7) I wouldn't want to damage it.