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Building Stone Steps for Mules & Gardens

Pack Mules on Duck Pass Trail

Pack Mules on Duck Pass Trail

The topic for this month’s design workshop at Gardening Gone Wild is dealing with slopes. The description mentions “tips for building steps and paths to make slopes easier to navigate,” so I thought I’d cite the source I learned from, the forest service Trail Construction and Maintenance Notebook, which is online and in the public domain (Who owns this government document? We do!). The text might have a few elements geared towards public trails rather than residential gardens, but the diagrams are good and the principles are solid.

Step Construction

Step Construction

‘Build stairways from the bottom up, at a break in the grade. The most common mistake is to start part way up a grade. If you do so, the trail will wash out below the stairs. The bottom stair should be constructed on a solid, excavated footing. If it is constructed on top of exposed rock, it should be well pinned to the footing. Each successive stair is placed atop [or against] the previous stair. Dry masonry rock stairs usually rely on the contact with the stair below and with the footing to provide stability.

‘Hikers, especially backpackers, generally don’t like steps and will walk alongside them if there is any opportunity. The steps need to be comfortable to climb or they won’t be used. This means keeping the rise a reasonable 6 to 8 in (150 to 200 mm) and the run long enough to hold a hiker’s entire foot rather than just their toe. It’s helpful to armor the sides of steps with rocks to encourage users to stay on the steps.’

Stepping Rock and Riser Stairways

Stepping Rock and Riser Stairways

‘The most important area of the step is usually in the run. This is where most traffic steps as it climbs. If the step is composed of something like a board on edge with fill behind it, then the traffic will step onto the landing. Almost all foot traffic descending the step will walk off the edge of the step. The top of the step (and landing) should be stable and provide secure footing. The edge of the step should be solid and durable. The face of each step should not contain a batter that creates a “face run” of over 2 in (50 mm) from top to bottom. This is particularly important as the rise of the step increases.

‘Steps with landings are a bit harder to secure in place because the stairs do not overlap. Each step can either be placed in an excavated footing and the material below the rise removed to form the landing of the next lower step. This is usually the most stable arrangement. Or the step can be secured on the surface and fill used to form a landing behind it. The material used to provide the rise does double duty as a retaining structure when the landing consists of tamped fill. These steps must be seated well to prevent them from being dislodged by traffic. For stock use, landings should be long enough to hold all four of the animal’s feet.’

Riprap Stairway

Riprap Stairway

‘In more primitive settings, you don’t need a uniform flight of steps as long as the route is obvious and there is solid tread at each stepping point. In the Sierra, a cross between cobblestones and stairs, locally called riprap, is commonly used for this purpose.

‘If the stairway climbs straight up the hill, each step should be slightly crowned to drain water to the edges or slightly sloped to one side. When the trail traverses a slope, each step and landing should be slightly outsloped. Water should not be allowed to descend long lengths of a set of steps or to collect on or behind a step on the landing. A drain dip where the trail approaches the top of the steps is a good idea.

‘In all steps, the key is to use the largest material possible and to seat it as deeply as possible. Rocks should be massive and rectangular. On steps that traverse a slope, it helps to seat the upper end of the step material in footings excavated into the slope.’

Rock Staircase

Rock Staircase

Best practice for building a stairway these days, if the rocks are big enough, is to butt them against each other instead of on top of each other. That way it is possible to repair one of the steps without redoing the whole staircase.

Rock Staircase

Rock Staircase

It doesn’t say in the notebook, but I was taught to kick test every step. If the stone moves when you kick it, it isn’t solid enough. A bit of a shock, sometimes, to see someone kick the structure you just labored on, but the step is definitely going to get kicked when people use it, so you might as well find out if it is going to last. You want to feel confident that your stairs are safe. It’s scary enough the first time you see a mule train crank through a set of steps that you’ve built even when you know the steps are solid. There aren’t mules in residential backyards, but the foot of a 150 lb. person can easily impact with 300 lbs. of force, so the basic principle is the same. Steps should be strong.

Steps also need to be regular. The test is to walk up and down the stairway without looking down at your feet. If the rise and run are even, you shouldn’t trip or stumble.

Old Town Wall Steps

Old Town Wall Steps

In the front country I usually don’t get to work with stones that are “massive and rectangular,” but I still kick test every step and walk the staircase with my eyes closed. This set of steps, built with a local sandstone called Old Town Wall, was a lot of work, getting the risers to all match and the stones all interlocked enough to stay in place. I was working for a designer who is a serious dry stone purist, so mortar was out of the question. I think the steps and cheekwall took me longer than the entire rest of the wall.

Mortared Arizona Flagstone Steps

Mortared Arizona Flagstone Steps

When it’s up to me — though I’m a dry stacker at heart — I usually build steps with mortar, usually by stacking flagstone with a recessed mortar joint. I don’t think that method holds up in areas with heavy freezes and probably not if the steps are going to be used by mules, but it does well in Bay Area yards. A before photo of these steps and another mule photo are below.

Before

Flagstone Steps, the Before Photo

One thing the forest service notebook doesn’t really mention is width. Width for steps is somewhat subjective and depends on the site. Around three or three feet usually looks good in a backyard (people need four feet to walk comfortably side by side); four feet is wide but good for a front entryway. Six feet, like these steps I was replacing, is usually too wide for a home garden. A lot of people have the idea that wide steps will be inviting — and to some extent it’s true that a steep narrow staircase is intimidating — but the best way to make steps inviting, I think, is to taper them. That tends to lead the eye into the next space. Taper as they rise, taper to the smaller space, widen to the larger space (less common, but it looked good for the flagstone steps we did in the SF Flower and Garden Show); keep the width consistent for a more formal look or when the two spaces are similar in size.

Mules on the PCT

Mules on the PCT

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8 Responses to “Building Stone Steps for Mules & Gardens”

  1. October 27th, 2009 at 2:42 am

    Deborah at Kilbourne Grove says:

    This is a very informative, but easy to understand article. I have a hill(very small) in my garden that needs some steps. You have made it easy for me to figure out the riser heights. The pictures are very beautiful as well.

  2. October 27th, 2009 at 9:23 am

    Susie says:

    Great article & beautiful steps. I love the improvement on the yard with the Arizona Flagstone steps…you are right, so much more inviting. I want the Old Town Wall steps in my next yard!

  3. October 27th, 2009 at 9:03 pm

    Country Mouse says:

    Very timely for me too – thanks so much for the great info and advice. I have two sets of steps to build and stone to build them with (it’s called Cameron sandstone). I’ve also used Sonoma field stone for risers in the first set of steps I built and so far they are holding up so I thought I’d try that again. I’ll be back to reread this post!

  4. October 27th, 2009 at 9:15 pm

    ryan says:

    I’m glad this was helpful. It helped me when I had to learn how to build steps.
    Cameron is good stuff. The steps should turn out nice.

  5. October 28th, 2009 at 11:10 pm

    chuck b. says:

    Wow, that sounds like a lot of work! I don’t think I would ever build my own stairs. Too much to keep in mind, too many things to go wrong. And then I’d be the first to trip and fall and break my neck. BUT, thank you for passing along the trail construction manual from the Forest Servive; it was very interesting to read.

  6. October 29th, 2009 at 8:01 am

    GBDW – Coping with Slopes Wrap-Up says:

    […] Building Stone Steps for Mules and Gardens (Ryan at DryStoneGarden): Ryan takes building with stone very seriously, so it’s no surprise that he offers some rock-solid how-to advice for building stone steps in this post. And in Cabernet Stone Terracing, he talks about considerations for terracing with dry-stacked stone walls. […]

  7. October 29th, 2009 at 10:53 am

    Pam/Digging says:

    I’ll be building some steps in my new garden, so thanks for the informative post.

  8. November 1st, 2009 at 8:46 pm

    lostlandscape(James) says:

    Um…how do these “massive and rectangular” stones get moved into perfect position? I’m surprised the Trail Construction and Maintenance Notebook doesn’t talk more about those details. The only stones that I unearth in my garden are treacherously round hunks of alluvium that some ancestral river in Mexico deposited before the faults moved them north and uplifted them a few hundred feet. I’m sure there’s some garden use for them beyond low walls, but I’d prefer some Sierra granite for any sort of walkway.

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