On the backside of this house that I bought, is a 11 step stairs, ending on a 10' flat deck that services the back entrance.
There are no risers on the steps (and the balisters are 6" apart, not 4"!).
I will put the risers on, shall I make them from 1x6 or 2x6 pressure treated wood?
I am doing this because someone told me that if someone slipped and fell and hurt themselves by slipping through the steps without risers, insurance would not cover it. I am also by the way, adding balisters so that they are less than 4" apart.
dvarga,
Let's clarify a few terms here first.
Since you have a set of 11 steps, the existing steps HAVE risers. "Riser" is simply the vertical support between each tread. That can be open, or it can be enclosed with a facia. I think, based on your question, that you are talking about enclosing them with a facia -- a vertical board between each tread.
WHAT you use to enclose them with depends on the amount of overhang that the nose of each tread has past it's support. If that overhang is 1-1/2" or more, then you could use a 2X as the enclosure piece. If the overhang is less than 1-1/2", but more than 3/4", then you can use a 1X, but NOT a 2X. You don't want the enclosure piece sticking out past the nose of the tread. If the overhang is less than 3/4", but more than 1/2", go to a 1/2" thick enclosure piece, OR install the enclosure piece so the the top of it is flush with the top of the tread.
Stairs are tricky. What you want is a tread that is 12" deep, the RISE between each tread between 7" and 8", (7-1/4" to 7-1/2" is most common), AND the VARIATION between the riser height NO MORE THAN 1/8" from the shortest to the tallest. (If the shortest riser in this set is 7-1/4", the TALLEST riser height can be no more than 7-3/8"! It doesn't matter WHERE in the set the shortest and the tallest occur.)
Current code calls for the pickets in the railings to have less than a 4" space between them. That is defined by 'the ball rule' -- a 4" ball cannot pass between them. (At the triangle formed by the stair tread, the stair riser, and the bottom rail of the railing, it's a 6" ball rule -- a 6" ball cannot pass through that triangle.)
Feel free to REPLY to this post with your questions. (I'm sure you'll have some!!)