We had another nice fall Saturday in Portland (cloudy & foggy but no rain), and I was able to get the stairs done on the garden shed. While building these was straightforward, making sure they won't be damaged by water over the years requires attention to detail.
I added 2x4's as strong-backs to the stringers, as suggested in a recent Fine Homebuilding article. These are glued and screwed in place.
Even though the stringers are pressure treated, I didn't want to set them directly on the footing blocks. The cinder block will wick moisture up to the wood - and over time it will take its toll in our wet climate. To help mitigate the this, I am putting asphalt shingle between the wood and concrete. This minimizes the contact area, and helps stop the water from wicking. I used poly glue on both side of the shingle to keep it in place.
I also put flashing on the top surfaces of the stringers, which have exposed end-grain. Adding these details costs almost nothing, but it takes extra time and planning.
Here is a picture of the finished product...
Once Spring rolls around, I will put the retaining walls in for the raised beds.