Slope on steps (outdoors) for drainage

[Barnrikehuset]

Hello!

I'm sketching a deck staircase and reading in some recommendations that the steps should/must? have a slope of about 1-2° for drainage (I assume to avoid ice formation).

I will use 45mm joists for the treads.

But in which direction? Inward for an open staircase, outward (slight slide) or sideways? Or will you feel it and the staircase becomes uncomfortable?

 

[Barnrikehuset]

Quoting www.byggbeskrivningar.se.

"Exterior stairs should have less slope than interior stairs.
The rise angle should be between 17° and 30°. The step height can vary between a minimum of 140 and a maximum of 200. The tread depth in stairs should be at least 250, but stairs with normal slope have about 300 deep treads. Step height and tread depth can be calculated using the formula 2 x step height + tread depth =
600 – 650. Example: step height = 150, the tread depth is: 600 – (2 x 150) = 300.

To avoid water gathering on the risers (and ice in winter), you can have a slight incline of about 1:50 (approximately 1.2°)"

"On the risers"? they are under the treads. Maybe they mean against the risers or on the treads?