Monday, June 1, 2009

How to build an urbanite path

Paths are very important features in the landscape. Paths guide visitors but also guide the eye. As a result, they are very strong design elements that must be considered in landscape and garden planning.

As with any path, the more uniform and straight the path is the easier it is to navigate. Knowing how the path will be used is essential.

Paths in a garden can be composed of many different surfaces depending on the aesthetic and intended use. Paths can be formal (wide and uniformly surfaced, like poured concrete), or casual, (small and uneven, like stepping stones). For a garden setting, varying the texture, size and construction of paths can be a useful tool. By varying width, straightness, evenness you can guide visitors through the yard, at different speeds. In a garden it might be important to move slowly and interact with your surroundings, whereas a sidewalk, uniformity, transportation, and safety are important.
In our front yard, the urbanite path is the only way to our front door, so it is a wide, gracious, level (relatively), and easily negotiated path (constructed following the steps outlined below). In contrast, in our sideyard (see above) and backyard, in areas that receives less traffic, the paths are narrower, more uneven, and are less formal. In keeping with the casualness, we placed soil between the concrete to allow yarrow (Achillea millefolium), bee balm (Monarda fistulosa), and hairy golden aster (Heterotheca villosa) to grow, which we then mow or transplant. This has not been super successful, but not bad either.


Building an "urbanite" path
I resisted using the term “urbanite” for a long time, it seemed kind of trendy and pretentious, instead I like to call it broken concrete, but, alas, I have given in since that is what everyone is calling it now.

Anyway, I digress. It is pretty simple to make an urbanite path and it follows many of the same procedures as any sort of paver path. Since the procedures are the same, and covered in more depth and better in a variety of sources from landscaping books, to online sites, I am not going into too much detail about how to lay a path, but rather considerations for using urbanite and using paths in garden settings.

The real benefit with urbanite is that is it typically free, and is a great use for old unwanted concrete. The key lies, as in most things, in the preparation.

Considerations:

  • Determine how the path will be used
    (e.g., high traffic, formal, main approach to the house or a secondary path)
  • Aesthetic
  • Use the largest pieces tat you can. But since they are really heavy- you might want to have someone help, and consider using a hand truck or furniture dollies to move the big pieces around or even a compact utility loader (see below)
  • Major pieces should be no smaller than two square feet
  • It takes a lot of urbanite for a path, so don’t underestimate the quantity
  • Use 4-6” thick concrete- it is good balance between mass and ease of use, anything thinner is probably too weak, anything thicker may be too heavy
  • Consider adding a curve or two (see these tips).

Where to get urbanite?
Check Craigslist, free classifieds and look around your town for sidewalk replacement projects. Contractors may be able to deliver it to you free of charge or for a slight fee (it will be worth it, if they can deliver it). In many places contractors have to pay for disposal. In Missoula many contractors grind it up or pay to have it ground for road base mix- this is a great use for the material.

What if you have some urbanite on the hoof?
If you already have some concrete you’d like to break up and re-use, I use a sledge, but you can also rent a jackhammer (electric are lighter and easier to use, gas and pneumatic are beasts). If you do rent a power jackhammer, my advice to you is let the hammer do the work- guide it and go with it. It will beat you up. If you use a sledgehammer, you have to do the work, but it is a great stress relief. In any case, regardless of the method you use, wear hearing and eye protection.

If the concrete does not have re-bar or wire mesh, it will be pretty easy to break up. If your concrete does have wire mesh or re-bar, fade back and punt. If it has reinforcement, the problem is that the chunks will be large and unmanageable- you could rent a Bobcat or compact utility loader (these are a lot of fun and it might be worth it to rent one for the heck of it, and just move stuff around, because you can). Again, I digress.

I don’t know of an easy way to tell before you get into it, but typically if is is an old sidewalk, say older than 50 years, it will probably not have reinforcement. If you are unsure call concrete cutting contractors in your area for advice- they will know.

As far as preparation, roughly mark out the path- a garden hose is nice tool for for this. And mark it with spray marking paint. A typical path should be 4’ wide, but less frequently used paths can be as narrow as you like, but try to keep them wider than 1.5’.

How to prepare the site and install an urbanite path
Dig down to a depth that will give you the concrete thickness, +1” sand, and 4-8” of compacted gravel base (using 3/4 minus or road mix). If it is over well-drained soil, or if it is not in a area that is frost prone you can get away with a lesser amount of compacted gravel.
Once you have dug down to the depth, install landscape fabric to keep weeds out and to keep the gravel from working its way into the ground. Also, add edging to the sides of the path to keep the urbanite path from shifting and to keep lawn (if applicable) out of the path. You can either use lawn edging first or specially designed brick or paver edging you can install after the project is complete. Adding edging in advance of the gravel base makes screeding a lot easier and it will provide a constant edge and level line for the project.

The next step is to add the gravel base. Add gravel in 2-3 in lifts, that is, a few inches thick at a time, and compact it, and add another few inches until you have reached the depth of concrete thickness + 1” sand. Screed the gravel to get it roughly level (Finally leveling will be done with the sand and the individual concrete pieces). Set in approximately 1” of sand, and screed again.

Now the fun begins.
Start by setting the concrete chunks next to the path and roughly layout the path in 3-4’ sections. Set the large pieces first and fill in with smaller ones. Spend some time selecting pieces, and have fun with this part. You might have to fine-tune some pieces, and this is easily done with a 2- 3 lb. drilling hammer (also called a fist maul or little sledge hammer), and a cold chisel or brick chisel. For breaking larger pieces, use a 6 lb. sledge. I like a 6 lb. sledge because it is a good balance between precision (small hammer) and mass (big hammer).
Set a few pieces and make any final adjustments by adding or subtracting sand. A rubber mallet is very useful for setting the chunks of concrete. Check the individual pieces for level and make sure they align with one another. Take your time here.
Once all the pieces are installed, spread about ½ inch of sand over the entire walkway and sweep it into the cracks, add more sand and walk on it for a few days and reapply sand as necessary. If you are working with a large area, use a plate compactor to vibrate and set the concrete in the sand and to work the sand into the cracks. In any case, the pieces will shift slightly and sand will fill any voids. After a few days, sweep off the remaining sand and enjoy your project.
Urbanite paths can be a formal or informal (rustic) as you would like or as it suits the rest of your landscape and your personal aesthetic. The thing to keep in mind is that urbanite is just a paving material, and site preparation and planning are essential.

14 comments:

  1. Thanks! That's very interesting and confirms that it was wise to hire some guys for my recent breakup.
    Another question: How will your new path be for wheelchairs and walkers? I have some elderly friends and I'm worried...

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  2. Great use for something otherwise added to a landfill around here. I love the look of this kind of path and would happily install one of my own, I just need to get my hands on the materials. Are you using the greenhouse yet?

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  3. Hi Town Mouse,
    Good question about wheelchairs and walkers- that is why it is important to decide how the path will be used in the beginning planning stages. Whereas, our front path would be easy to navigate, our back paths could be more challenging (or impossible for a wheelchair). If you were to design a path with accessibility issues in mind, the joints should be smaller, and use the largest pieces of concrete you can find. Finally, devote more time to site preparation and compaction to avoid shifting with frost and freezing. Just like any paving material, it can accommodate a wide range of uses and styles.
    Thanks again for a great question,
    David

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  4. Well explained and illustrated. Thanks!

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  5. Wondering if you've used a concrete saw before. I am concerned about breaking the pieces, and looking for tips for getting the largest pieces possible and good shapes.

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  6. Also, if you've experimented with staining the concrete.
    Love your paths and descriptions!

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  7. Hi Margo,
    Thanks for your comments, and compliments! You can use a concrete saw, but be prepared they are dusty or messy (if you use a wet saw). If you are looking to just get a strait edge you could score it with a saw, and then break it with a hammer. As far as working with really big pieces- it is difficult for a few reasons. The main reason is being able to move them- they get very heavy, very quickly, but if you have help or equipment (like a bobcat), really big pieces are nice, but they are also harder to level. I haven't stained concrete in place. Good luck!

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  8. David,

    My wife and I are using "urbanite" to completely revamp our back yard!

    So far, we've made several retaining walls, a firepit and last night, we finished a (roughly) 8X8 patio that leads into some sandstone flag steps(we got the flag from a local landscape center that was going out of business and practically giving them away or we'd have used 'crete for those as well!).

    We used crushed bluestone(stone dust) as a base and to fill in the joints. Initially, I thought my wife was nuts when she first told me about the idea, but since then I couldn't be happier with the results. I figure we've saved thousands on materials as well has not having to dispose of the concrete that we broke in the yard!

    Cheers!

    PS I also borrowed a Bobcat from a friend for much of the project, and it is LOADS(pun intended) of fun!

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  9. You can use a concrete saw, but be prepared they are dusty or messy. Concrete Cutting Los Angeles

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  10. Very Nice, I am using urbanite for a driveway, 450 sqr feet..I have quite a lot of work to do this summer

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    1. Glad this post was helpful- thanks for the comments! My only advise is to take plenty of pictures, before, during and after. Good luck!

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  11. I know this is an older post but I need to know how an urbanite path holds up to snow removal. I need an ice free path for young children and parents with infants. I appreciate any advice!

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