One thing I decided up front was that the beams should all rest on the posts at both ends. That is, it is possible to connect a beam between two posts using only metal connectors and nails or screws to support the beam. In that case the weight of the beam rests directly on the metal connector, and only indirectly on the post. This can work, but extra strength is provided if the beam sits right on the post. In that case the metal connector's role is more to keep the beam in place, not support the weight.
Given this, 1 post would support 1 beam, 2 posts would need to support two beams, and 2 posts support 3 beams. Given that the area on the top of each post was only 4x6 (well, technically slightly more on the sloped-top posts, but not a lot more) that meant some special planning and cutting would be needed in certain cases.
This next picture shows the south ramp after the beams were in place. I'll use this as an aide to describing the construction work:
The first beam to install was the one on the top of the staircase -- in the upper right of the photo. This was easy as the posts were level and the distance relatively short, at 41 5/8". Just put the beam on top and use strong-tie connectors to keep in in place. But this beam also took up 2/3rds of the area on top of those posts, leaving only 1/3rd for other beams.
The next beam was the sloped one on the left side of the photo -- this actually went from the timber (bottom of photo) and rested on two posts. Again pretty simple. I had to trim the far end so that the post end was vertical (being sloped, the end would normally also be sloped, which would get in the way of the adjacent beams). I also had to shim under the beam at the timber end. I had to do this for all the beams as the final tamping down on that timber lowered it slightly. (When I later installed the timber at the bottom of the stairs I took this into account so that the final tamping resulted in the timber being exactly the right height.)
The next beam was the sloping one on the lower right of the photo -- similar in execution to the last one. And this was the last of the easy beams. The rest all required special measurements and cuts.
The beam that's farthest from the camera came next. This required some additional p.t. wood support on the side of the 6x6 post on the left because that post height was set for 7 1/2" beams (used on the bridge). Otherwise, though, the cutting wasn't too bad because while each side required angles the slope was nearly flat.
The final three beams had to follow a logical order -- as it turned out from left-to-right in the photo. All of these required special cuts to fit on the posts and, for the first two, to allow enough room on top of the post for the next beam. Some required shims. And two of those beams were over sized (one almost 7" tall) so they needed to be trimmed down over the posts to keep the beam height consistent.
One point about this is that the circular saw blade goes only 2" deep, but most of these cuts required going through the 6" length of the 4x6. The ideal saw for this is a mitre saw, but I don't have one. So I had to carefully measure and cut from both sides with he circular saw, then use a manual saw to get the rest. Ugh. Christmas is coming up -- I think I'll add a mitre saw to the wish list.
That last picture was on September 15th -- only 5 days after I started measureing for the south ramp. This next picture was 2 days later, after the joists were in place:
You can see the joists are pressure treated (p.t.) 2x6 lumber, the sick green of the p.t. joists very distinct from the brown of the landscape timber 4x6 posts and beams.
Two double joists (that is, a joist using 2 2x6's together) were used where other joists would attach to them. One is between the two posts nearest the wall. The other is between the far beam and the post across from that. Otherwise all the joists were under 5' in length, and they were positioned so that the planks would never have to go more than 18" span between two joists. As noted earlier, wider spans can result in planks that sag.
With beams and joists in place I decided to tackle the stairs next before addressing the planks. I pulled out one of my old deck building books and started at the task. This shows the stair infrastructure on the 19th, two days after the last photo:
The first thing about the stairs was understanding the length of the steps and the height of the risers. The deck plan book suggested that deck stairs should have slightly longer steps and slightly shorter risers than interior stairs because of the nature of decks -- that people feel more comfortable with less steep stairs on a surface that doesn't seem quite as solid as, say, a carpeted floor. It suggested using one 2x6 plank for the riser and 2 for the step. I took this suggestion and measured the height the stairway would need to account for, then got out some graph paper to carefully plot out the "stringer" (this is the length of wood that supports the steps) profile. The book said 2x12 could work for a stringer, and I found 2x12 for both redwood and p.t. fir at Lowes -- $27 for an 8' section of 2x12 redwood!!!
As the width of the stairway is 41 5/8" I had a bit of a quandary. At 36" width I could get by with 3 stringers, which would result in an 18" span between stringers, which as I've said is the ideal. At 41 5/8" the span is now over 20" and that's less than ideal.
Then I considered that I really wanted the outside stringers to be redwood for looks, but redwood is a soft wood and a lot weaker than p.t. fir. So I settled on the idea of 4 stringers, with two p.t. stringers in the middle positioned to take most of the weight (18" apart) and redwood stringers on the outside supporting only a small portion of each plank. You can see that in the photo.
Cutting the stringers is not hard if you have an L or T measureing tool -- I have an L tool which is perfect for this job. Even then this is a job where precision counts. Measure numerous times to make sure each stair is even and of the same measurement as all the rest. Cut carefully -- I used a manual saw at the step/riser points rather than risk over cutting with the circular saw. Once you have one stringer done (start with the cheaper p.t. fir in case you need to redo it) and the measurements verified, use it as the template for the other three.
I used standard 2x6 joist hangers for the inside stringers and expensive ($6 per) stairway joist hangers for the outside two - as only they would fit a stringer than needed to be right at the edge of the post. After measuring I had to rehang one stringer, then they were all found to be level and even at every point.
The base of the stringers was a landscape timber installed in the same way as the timber at the top of the ramp, as described earlier. In fact, I used the other half of the same piece of timber for the base. In this picture the dirt around the timber is high -- actually too high since dirt close to redwood will reduce the life of the redwood. I removed a lot of the dirt later.
The next post will cover the planking of the stairway and the rest of the south ramp.
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