Wednesday, September 23, 2009

What I did last summer (part 6): the north side ramp

I'm still not sure what inspired the goal of having a step-free ramp for a walkway from the driveway to front door. Certainly one influencing factor was that the walkway we inherited had very long and uneven distances between risers, forcing you to have to take awkward half-steps on the way up or down. Or maybe it was when the kids asked if they could ride their bikes on it.

In any event, it seemed like a good idea, and if ever we need to host someone in a wheelchair we'll be in good stead after this is done.

My original concept was that we'd put in brick pavers for the start of the walkway where it meets the driveway, then transition to a redwood boardwalk at some point. Then while looking for something else at the rock/sand yard I saw some "red breeze" path cover on display. This is basically a mix of red clay and gravel that makes for a nice informal pathway. The kids loved it -- and when I priced it out ($$cheap$$) and saw how much easier it would be to install than brick pavers, I did too. Given the low cost it's also practical to try it now then replace later -- or even put thin pavers on top of it as once it settles it can serve as the sand basis that you are supposed to put underneath pavers.

Fortunately, my wife also loved it when she saw it. So, next up was to find a material for edging the path. Another fortunate stroke is that my neighbor used the composite material that is highly-touted by Home Depot on his path last year and it was horrible. He and I ended up both selecting a metal border that is on the pricey side -- about $1.70 per linear foot -- but very sold and easy to use.

So, got the edging material, and picked up the old can of spray paint tape measure and plotted out where the path would go. This is where all those years laying N scale track actually proved useful. When you lay track you have to plot out tangents, curves, and spiral easements. I did the same here, and didn't hesistate to make approximations because I'm used to doing it. I wanted the path to be 4' wide, but settled for slightly more when it all got plotted out. Then spent some time getting familiar with the edging material. I took September 2 off from work to work on this and other things, and this photo shows progress at mid day:



Ok, so the basic shape of the walkway was there, but where exactly should I place the transition from clay walkway to boardwalk? I realized that within a space of 4-6 feet the transition could go anywhere, so I chose a spot that would allow me to bend the edging and use a continuous series of 3 10 ft. edging pieces without having to do any cutting. Then I hammered them in, adjusted, rehammered, etc., until everything looked in order. This photo shows the result later that day, after I started the digging process to make room for the boardwalk:



You can see that I'd been tossing the dirt from the digging into the red clay path area. This is because the edging is 4" tall and I wanted to have 2" of tamped down dirt covered by 2" of clay, so needed to move some dirt over.

At the time I took that picture I was thinking "man, this digging is going to take forever" because the soil was hard (no rain for a few weeks) and the digging tools I had were just taking a long time to loosen it. Then I remembered I had a large pickaxe that I'd used only for things like narrow ditches. It did quick work of loosening the remaining dirt so that I had sufficient space to put in the concrete footings for the boardwalk ramp.

For the footings I used pre-cast concrete which in theory does not need any poured concrete around it. But also in theory it's not to be used on slopes. So I got a couple bags of concrete and used that as the base on which the concrete footings were set. One pair of footings was just over 7' from the north end of the bridge -- I planned to use 2x8 lumber for the beams from those footings to the north end piers. The other footings would be roughly 4-5' further down the path (not exact because the path was curving) and about 1' from the transition point with the clay path. For that section 2x6 lumber would be used because the support area was shorter. In reality 2x6 would probably have been fine for all of it, but i was being extra cautious.

I tried to get the footings to be set in such a way that they were level from side to side but matched the slope of the ramp going lengthwise along the path. The side-to-side is easy because you just use a level, but matching slope is much harder without advanced surveyor equipment (see earlier comment about being a cheapskate sometimes) so I did my best and came with a half inch, which could be addressed with shims. By September 5th the substructure was taking form:



Some things to look for: First, the cast footings are sitting on mounds of dry concrete, although it may look like dirt in the picture. This results in a very solid platform and distributes the weight nicely, making it unlikely it will settle. The dirt underneath was not loose, and had been tamped down just in case before hand. Second, you see the pressure-treated (p.t.) fir beams in place on the footings, with metal tie connectors holding all in place. This too was very solid and did not move much even when shaken. The weak point was at the transition with the clay path. I put a board of 2x8 p.t. to keep the dirt wall from eroding (you can see that by the green edging at the bottom of the photo) and held up with metal spikes that were pounded into place. This is fine for that purpose, but not fine for providing beam support. However, as I had no other option I rested the end of the beams on that board, using shims screwed into place to assure they stayed there. I suspect this will create a maintenance issue in a few years as the board shifts or erodes. Oh well, it does work and we can't see the problem externally now.

Shortly after that the rest of the substructure was ready, with the middle joist in place to support the middle of the redwood planks:



You can't really see it here, but by this time my son had tamped down the dirt in the clay path area to be 2" across and solid. This helped the next morning, as I started the day by first putting in fabric cloth, using fabric cloth staples, over the dirt in the area of the clay path. The fabric cloth keeps things orderly and separate, and also keeps weeds from growing up while still allowing water to trickle through.

Then, same day (September 7, Labor Day) I put the planks down. The ends of the planks were only in approximate location as I intended to cut those to shape after the boards were in place. You can see in this photo the planks in place and also some of the black fabric cloth below:



A couple points to note on the above. First, the place where the redwood touches the edging was a royal pain to cut. The edging at that point is an irregular curved shape, not amenable to tracing on the wood (although I tried at first) and I ruined one plank learning the process. I eventually used a pencil-compass, with a fixed length, to draw the correct line and saw it into place.

I also was forced to deal with the reality that I have two bad jigsaws. One I bought new, let a neighbor use it before I did, then by the time I used it realized the blade never went straight. I don't know if the neighbor did it or it came that way. It's Black and Decker, a brand I've not had good luck with on any tools in the past few years. The other was a Rigid, which has a great rep, but I got it from a reconditioned parts store in Castle Rock, CO, and it too never has been able to keep the blade straight. Sigh. Both of them caused problems cutting this plank and I finally resorted to a manual saw. I've had two great Bosch jigsaws in the past -- one was 220V and I had to sell it when I left Germany, the other burned out after over 10 years use in California. However -- kudos to my Dad, who sometimes reads this -- for semi-permanently loaning me his jigsaw after I complained about this to him. His is just outstanding. I have two lousy jigsaws available now to sell very cheaply.

My second point was that I struggled with how to cut the planks to accomodate the curve. Yes, I once was a math major, but shockingly the last college math course I took was over a quarter century ago. I can get by with geometry, but no matter how much I measured and drew I wasn't happy with the answers. Eventually I used a table saw (which I got for my birthday -- thanks Ann and Dad) to cut the planks seen above, then alternated between normal planks and trimmed planks. It seems to work, no one complains about the looks or even seems to notice, but aesthetically I think I'd have liked it better if the planks around the curve were all of the same size/shape. I will be using that approach on the south ramp.

Later that same day I started trimming the edges, but didn't really complete until the next day, as shown here:



All in all the north ramp has worked out. I do still need to add railing to the part near the bridge and I want to add 2x redwood to the side of the ramp, right underneath the planks, to improve the appearance. And of course I the red clay is needed. But everyone seems to like the overall appearance, the way the lines flow, and also the sense of how this bridge invites people into the garden and -- hopefully -- will help emphasize the garden when viewed from the bridge.

Once I finished this I had some serious design struggles for the south side. When I resolved them I realized I would need an even more challenging ramp *AND* a set of stairs. But that is for the next post.

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