Replacing a Rotting Stair Riser

The top riser of the back porch is rotting and needs replacing. Tonight I started that process by fitting the replacement riser.

Supplies needed:

6' length of 2x8 Pine
Shims
Drafting compass
Saber Saw or Coping Saw
Pencil

I discovered the hard way that even though Home Depot and Lowe's carry risers that are 48" long, your riser might require something longer. So, after two trips for lumber I was ready to start fitting using the 6-foot length of 2x6 pine I'd procured. I suspect that someday I will wish I had purchased poplar, but pine it will be.

The riser height was not exactly equal to the space (room for movement), so I had to shim it up into place to get a marking. Veritas has a fancy gadget, called a transfer scribe, for marking odd shaped ends, but I just used my standard compass. I set the compass to a width greater than the deepest section of the step against the house and simply dragged the tightener against the house while the pencil scribed the board.

I then cut the shape using a saber saw. I returned to the back porch and inserted the riser to see how well I had done.

The fit was good enough, so I went to the other end of the board and marked it directly from the porch. That measurement was not the correct length, because the end is capped by another board. So, with the direct scribed line, I knew I had to subtract the width of that other board. I Using the compass again, I set the compass arms to exactly the with of the end board, then used this setting to shift the mark to where my cut needed to go on my riser. I took it back to the basement and cut it square at the mark.

After tonight's work, the riser is ready to prime for painting, which I can do in the basement this weekend (even if it does rain outside, with the arrival of Tropical Storm Hannah). If all goes well I will be as happy with the fit of the new riser as I was with the old one (installed by a professional carpenter). So far, so good. Here's the before and after shots: