Building Stone Walls with Urbanite

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If you’re wanting to build beautiful stone walls for your landscape  – urbanite rocks!  “Urbanite,” better known as waste concrete, is plentiful; lasts pretty much forever; is easy to work with and in most cases … it’s free!  Surprisingly, few people take advantage of this great material.

Urbanite replaces our need for stone or new concrete blocks – the primary materials used for landscape walls.  Stone requires mining and often has to be transported great distances.  Concrete is an energy hog.  Its fabrication accounts for 5% of our global emissions. Reducing our need for new material and making good use of what we have makes ecological sense.    If you’re concerned there may not be enough of this for your needs, don’t be.  Our rapidly changing environments create more of the stuff every year.  It’s rock-bottom price should give you a pretty good idea of the ratio of supply to demand.

We’ve seen some installations of this material that were  … ahem… aesthetically challenged, so we decided to collaborate with Hector Santos, a professional stone mason and sculptor.  We wanted to bypass the learning curve and see what was really possible.  It was a great decision.  Hector brought a wealth of knowledge and stone craft to the process and patiently shared how those techniques could be adapted to urbanite for a beautiful result.

Here’s an account of our journey and what we learned:Harvesting waste concrete material from our local "quarry."

We stopped by the local landscape yard to pick up some materials.  As you can see – we had plenty to choose from.  This pile is about half an acre in size and more kept showing up every day.  The yard owners were extremely generous and allowed us to take as much as we wanted.

Most waste concrete is from concrete slabs and measures about 3″-5″ thick. We sought out material that was relatively uniform (flat on both sides), free of reinforcing and manageable for 1-2 people to transport.  We tried to bring home a variety of thicknesses (to add interest to the wall) and were lucky enough to find some scrap slate shingles (good for shims) and some round rocks – which added some artistic interest here and there.

In all it took us about eight trips.  With the supply yard close by, that allowed us to use up each load as we went and end the project with very little left over.

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We decided to build two sets of walls.  The first – a carefully dressed and tapered barrier between the Cargo Shed and the parking area.  Its purpose: to enclose a pair of rain garden which slow and filter the road runoff prior to releasing it into a bioswale.  The second set of walls would be conventional retaining walls for the landscape beds.  These were much easier to build, so for the purpose of this post, we’re going to focus on the free-standing elements.

To start, we excavated a shallow footing (ideally about 12″ deep) and filled it with crushed rock (free of binder).  Eliminating the binder allows the footing to drain water easily.  Hector prefers a heavier ballast rock for this application, but we found the 1-1/4″ rock to work quite well.  The footing needs to extend beyond the footprint of the wall (for stability).

We utilized a rotary laser mounted to a tripod for uniform leveling of the wall. This is an important detail as having a level top really helps to give the wall a finished appearance.

We inlaid gin bottles into the wall for accent and night lighting (illuminated with 12v LED lamps).

Elsewhere on our property, we’ve used recycled gin bottles as landscape lights.  Carrying the theme one step further, we integrated them into the structure of the wall at even intervals.  The square nature of the bottle compliments the blocky urbanite and the aqua color adds a little interest.  At night, these are illuminated to a soft glow by low voltage LED lamps.

In this photo, you can see the rebar stakes that Hector used for consistent alignment of the sloped wall.  The strings are moved up as the wall courses higher.  Round stones are added here and there for whimsy and artistic value.  When needed, they can be cut or flattened with a diamond blade on a 4″ grinder.

Blocks are laid out to lap onto other blocks below i.e. joints do not align vertically through the wall.  For a dry-stacked wall, this ensures structural integrity and reduces settling.  Block heights are randomized to avoid a coursed or “layer cake” look.  Mortar (Type “S”) was used only where round rocks were used, to stabilize the top cap, or where the blocks weren’t able to penetrate at least 8″ into the wall interior.  The bottles are laid loose in the wall in fitted slots – so that they can be removed for light bulb access.

Perhaps the most important step in making a professional looking wall is to take the time to shape the blocks.  This is where Hector’s experience really came through.  Most people rely on fitting stones together, but for a tightly jointed wall, shaping is necessary.  It’s actually not that hard and can be done with just a few tools:

To trim a block, scribe a line with a diamond bladed grinder.  The cut relieves the surface tension and helps the block to break along that edge.  This can be done to the top and bottom surfaces for better control.  Then, using a cold chisel and a hammer, whack along the kerf until the block breaks.  It takes some practice.  The deeper the kerf, the more likely the block is to break along that joint.

 

Taproot_StoneWall - 18Shaping the stone face with a cold chisel to create a uniform appearance on the wall (similar to stone).

To give the concrete a more uniform appearance (resembling stone), we chiseled the exposed face of the smoother blocks.  That may sound hard, but it actually goes pretty fast.  We would cut a shallow kerf about 3/8″ from the face of the block on the top and then spall off the face.  We elected not to do this for the landscape walls and it still looked OK, but this attention to detail really results in a higher quality finish.

Taproot_StoneWall - 17Another technique we employed was splitting the larger pieces into smaller chunks.  This was done with “feathers and wedges.”  Basically, you drill holes (with a roto hammer) evenly along a slot cut into the top surface.  The holes are about half the depth of the material.  You then insert steel wedges and L-shaped “feathers” and pound away.  The goal is to drive the wedges in at the same rate so that even pressure results until … presto the block snaps in two.  This whole process takes about five minutes and can quickly turn a large unwieldy slab into smaller useful pieces.

If you’re feeling lucky and want to try a faster method, you can try just cutting a deep groove on the top and bottom of a block and whacking the slot with a cold chisel.  If the combined cuts are about 2/3 of the block depth, this tends to work pretty well.  Less than that and you’ll need some luck.Taproot_StoneWall - 12

If you do this professionally, or just happen to love tools, then a concrete wet-saw makes quick work of block shaping. Here’s a picture with Hector unleashing its might on a corner block.  It should go without saying that safety gear is essential.

In our case, we wanted an architectural wall reminiscent of the CCC era masons.  Their work is still in service in our local parks and is testament to the longevity of this type of construction.  Toward that end, we felt it was worth a little more effort for something that will be around a long … long time.  Hector likes to say that “stone is forever” … and in the context of our lifetimes, that’s a very true statement.

 

 

Here’s a picture of Hector and Matthew sitting atop the finished wall.  Optimal sitting height is about 18 inches.  While the ground slopes along the wall length, it averages about that height.

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Natural color variation in the urbanite adds interest.  Some of our material must have come from a boat ramp as barnacles have encrusted the surface.  It just blends in … until you study it closely and then you’re like “Hey Wait a Minute!?”

I love it when architecture reveals more to us the deeper we look.

Here’s a few parting images. The first shows the whole assembly in the early morning.  For the rain garden, Sarah complimented the native reeds with dogwood, iris, juncus, camas lily and gunnera.  The background wall steps slightly where the higher parking lot wall meets the lower path wall.  Visually, the two flow into one another.

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The latter image shows the landscape wall along the path.  Here, the back side of the urbanite is buried into the soil, so uneven pieces are easy to fit into the wall assembly.  Gravel is backfilled behind the blocks for stability and drainage.

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If you decide to use urbanite on your next project, send us a photo … we would love to see what you come up with.  If you’re nearby and want a skilled artist to help you realize your vision, give Hector a call.  He’s currently plying his skills in Vermont, but is willing to make the journey west during the long cold New England winters.

Installing a Living Roof – Fast!

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Over the years, we’ve been a strong advocate for living roofs.  Their beautiful form graces many of our projects as well as our home and office.

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The appeal is many-fold:  Living roofs replace the ecology disturbed by buildings by moving it upward – to the roof level.  There, planted roofs provide habitat, carbon sequestration and oxygen. They reduce and filter stormwater.  They extend the life of roof coverings (up to 2x) by shielding them from UV, environmental wear, and extreme temperature.  Plants add a dynamic element as well.  They change with time and seasons and the resulting beauty provides considerable psychological benefit.  We like the way that they help to connect us to the natural world.  During migrations, we often find flocks of birds resting on our roof as they take a break before flying on.

We’ve explored many different ways to build a living roof and finally had the opportunity to utilize Blooming Nursery’s Greenfeathers system.  It’s by far the quickest installation that we’ve seen and the result is a completely grown in roof – all in the course of a day!  The secret is  in planning ahead.

Green Feathers Delivery

The Greenfeathers system is a series of modular 1′x2′ trays that are pre-grown at the nursery.  The designer specifies the right plant mix (based upon climate, sun exposure, aesthetic requirements, drought tolerance, etc).  The nursery then grows the flats ahead of time at their facility.  Hence the planning ahead -  it takes several months to grow the plants to maturity.  Once they are ready, the flats are delivered and ready for installation.

Installation is fast.  The roof we planted was a few hundred square feet and took about half a day.

The principles for installation are simple:Living Roof_CleanLiving Roof_SingleLiving Roof Install3

  1. Start with a professionally installed, fully waterproof membrane roof
  2. Add a complimentary layer of material to protect the membrane from puncture during installation.  In our case, we used a second layer of loose laid TPO roofing (ballasted by the planted roof materials).
  3. Use drain rock around the perimeter, scuppers, drains, and building edges where you don’t want plant materials to deteriorate other parts of the building such as cladding or trim.
  4. Install the plant trays in a tightly fit configuration (measure the roof ahead of time and plan your layout).
  5. Remove the edge liners from the trays.  This will allow the plants and soil media to blend together between trays so that the roof can grow together into one densely grown mat.
  6. Water in the roof deeply and intermittently as recommended until the plants are established.

While at first blush, the system seems more expensive than other DIY installations, it may in fact be cheaper (especially for smaller roofs).  Finding and procuring good roof soil can be difficult and time consuming – as can finding an adequate supply of plants suited to your roof. If you are planning well in advance, you may be able to coordinate with other projects in your area and thereby share the delivery cost.

Speed is a big advantage with this system.  By having fully grown in plants, the roof soil is never exposed to weed seed – which virtually eliminates the likelihood of invasive plants establishing themselves on your roof.  Dandelions and other aggressive interlopers can put strain on your waterproofing membrane, so keeping them at bay is important.  Since roofing soils are not exposed for any length of time, they don’t need to be protected from erosion.  Further, the grown in materials are suitable for steeper roof installations (where baffles would be required to keep soil from sloughing off the roof).  Finally, installing fully mature plants means instant benefits:  Stormwater retention, oxygen production … you name it!

One consideration we weighed was the additional plastic prevalent in the trays that are installed with the plants.  Upon reflection, we realized that virtually the same amount of plastic is used for tray delivery at nurseries where the plants are grown, delivered and sold.  So, unless you are installing plugs or cuttings the resulting embodied energy is about the same.  The benefit of this system is that the installed trays do act as a root stop barrier and will facilitate the removal and replacement of the plant materials if and when the roof membrane needs to be replaced.

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Overall, we were quite pleased with the experience.  Designing far enough ahead of time, we were able to choose just the plants that we wanted (rather than the ones commercially available at the time).  The speed of installation was a huge plus … and the satisfaction of seeing a complete roof after only a few short hours was priceless.

Tiny House – The Making of the Kingfisher

Tiny House PerspectiveWhen friend and master craftsman Dan Neumeyer, approached me about collaborating with him on a tiny house it piqued my interest.

So much of design is about stripping away the unnecessary so that only the essential remains.

Tiny houses do this.

They reduce the footprint of the material world greatly.  In doing so, an alchemical process can take place; one where the reliance on things for satisfaction can be replaced by a love for experience.  That is not to say that the two are mutually exclusive, only that in a Zen kind of way, consciously reducing materialism in one’s life can act as a catalyst for engaging the world more.

I agreed to the endeavor.  My only requirement was that in addition to creating a well-crafted home, we also incorporate sustainable technology wherever it made sense.  Dan enthusiastically agreed.

I grew up in a wooden boat community and am well versed in the magic of small spaces.  However, to learn more about the subject, I decided to research a little deeper.

After reviewing many unique home-built creations and the catalog of Tumbleweed designs, I discovered an interesting pattern:  Nearly all tiny homes are designed with entrances on the end of the building.  This preference, I concluded is primarily aesthetic.  That is, when you visually scale down the iconic home, the natural place for the entry porch is at the end; where the peak of the gable roof provides the silhouette seen in almost every child’s drawing.  This aesthetic preference I realized, runs counter to the function of a home of this size.

In scale and function, tiny homes are similar to travel trailers.  So, when is the last time that you saw a travel trailer with an entry from the end?  Hmmm… that’s a head scratcher…

The reason is fairly simple.  By accessing the building from the end, much of the building length needs to be kept open and available for circulation.  So, I asked:  “Can you design a Tiny House with the iconic look and feel of a home with the economy of space found in an Airstream?”

The Airstream (like most trailers) places the access point on the side about 1/3 of the length from the end.  That allows both ends of the building to be utilized for dedicated purposes and reduces the walkway space in the middle.  Over time, this model has been tested and found to work pretty well.

Kingfisher Elevation

With the layout goals identified, I explored the character.  Much of a home’s style is driven by the roofline.  Given the narrow width of a trailered home, eaves really aren’t all that compatible.  Therefore, I concluded (like many others) that the New England style with its bobbed eaves and wrap around gutter really was the best stylistic fit.

Chances are that you’ve seen the building already in our portfolio.  So, here it is in plan view with annotations explaining its features:

There’s ‘small houses’ and then there’s ‘Tiny Houses.’  I’m not sure where the demarcation between the two is, but considering that the internal area of the Kingfisher is a mere 115 SF I would classify it solidly in the ‘Tiny’ category.  The side entrance design allows for a highly effective use of the space.  So, despite it’s diminutive footprint, it can comfortably sleep four and with the kitchen directly accessed through the main door, it readily connects to the outside for outdoor dining and entertaining.

 

 

 

 

Cargo Shed – Complete

ToolBox

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The curved roof provides a nice compliment to the box below.  It is fashioned from aluminum so it won’t leach zinc into the watershed (harmful to aquatic critters).  The space above the container gives ample storage for long materials.  It’s surprising how much – a personal mini lumberyard!  EMT pipe provides a series of shelf supports for easy sorting.  The circular nature of the pipe makes it easy to slide material in and out.  Materials can be accessed from both the interior and exterior.  This is perfect for both the rainy day project and the über long materials that you didn’t think you could store anywhere (up to 40′ in fact).

Cedar siding culled at the mill was used for the upper walls.  Deep overhangs protect the ends and provide shelter when accessing material.  Flip up screen doors are envisioned for the ends, but so far bees and birds have not been inclined to call it home  – yet!

We finished the building by adding a porch on the backside.  It functions as a covered work area or a three season lounge overlooking the garden (depending on our needs).

Overall, the building has been incredibly useful and adaptable.  The rooms can support anything from shop space to yoga.  Since both rooms have large doors to the outside, moving large items in and out is a breeze.  Now that it’s re-painted, anchored to a foundation, and capped with a generous roof, the building should last a very very long time.

Cargo Shed – Storage Loft

Cargo Loft Deck

Cargo Loft DeckThe roof is the weakest part of a shipping container.  It’s flat, so the salt spray from sea voyages has been slowing working away at its surface.  The metal used is a thin gauge and if left uncovered, the existing corrosion would have only gotten worse over time.  We thought about just adding a simple roof over the container, but realized that if we were going through the labor of building a protective roof system – why not add a little extra height and utilize the space for storage?

Matthew comes from a lineage of fine woodworkers so he’s always trying to find some place dry to store lengths of lumber and materials.  The space above the container is perfectly suited to this.  It keeps the material close to where it is needed (the shop) and the design allows for access from either end or the center of the building.  Therefore, short or long lengths can be stored with relative ease.  In order to make the space really usable, we decided to add EMT pipe supports to divide the space into a number of short bunks. The tubing is strong, inexpensive, and acts as a roller for loading and unloading material.

This photo shows the floor deck and knee walls (prior to being raised into position) for the upper storage area.

For a little aesthetic fun, we decided to cap the storage area with a curved roof…

Cargo Shed – Interior Finish

Paneling

PanelingOne of the psychological challenges in using containers is their cold interior.

Despite the ‘cool’ industrial factor inherent in steel design, very few of us opt to live inside metal boxes.   We went with our gut on this one and decided to sheath the interior with wood paneling. 

The wood gave us a tough surface that we could fasten just about anything to and rearrange things over time.  In any kind of industrial building, adaptation is key.

Our wall system is 1×6 t&g pine, stained with a (zero VOC) warm  tone.  For additional storage, we applied shelves high in the space with inverted shelf brackets (installed above the shelf).  That way, the wall surface remains clear.  If gusseted brackets are used, this technique also provide bookends at regular intervals.

The paneling provided a more forgiving installation than say plywood.  For, as you recall, containers are neither plumb nor square nor level.

 

Cargo Shed – Insulation

Foam

FoamShipping containers can be really damp inside. The combination of cold steel and humidity often results in condensation and a lot of it.  The moister the climate the more problematic this is.  Here in the Pacific Northwest, water literally rained off of the interior surfaces during the winter.

Understanding condensation is important.  Each climate is different, so the lessons given here may not apply to other locations.  I would highly recommend hiring an expert to help you determine if moisture is going to be an issue ahead of time.

A shipping container’s interior surface is corrugated, so it’s difficult to prevent moisture laden air from reaching the steel.  In our case, we applied a modest layer of closed cell spray foam to the interior which bonded to the uneven surface and moved the dew point away from the steel to prevent condensation.   The foam also acts as a sound dampener and helps to mitigate temperature swings somewhat.

We used a two-tank kit that we purchased online.  Installation was fast (1-2 hours).

Cargo Shed – Framing

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IMG_5947Contrary to popular belief, containers are neither square, level, nor plumb.  The weight of five other containers stacked above causes them to bow out over the years.  They are built to general specifications, but we found a fair bit of variation in ours – tolerances up to an inch or so of deviation.

In order to preserve as much interior space as possible, we used 2×2 studs on the interior.  They were too slender for the  8 ft. span, so we welded on an angle bracket at the middle of the stud for reinforcement. We then ran our wiring behind the studs using the wall corrugations as additional maneuvering room.

We used 2×4’s to support the ceiling (While the walls are designed for strength, the roof is designed simply to keep the water out.  It is constructed of thin gauge steel similar to that of a car roof.  Since the container floor carries all the load, even when stacked, there is no direct load on the roof.

The electrical panel required a deeper wall cavity to contain the box and conduit, so we boxed it in with 2×4’s instead of 2×2’s.

The floor is constructed of 1” thick mahogany plywood that is drenched in pesticides (to prevent spreading critters all
over the world). If you’re concerned about your health, consider encapsulating the existing floor by covering it with a finish floor.

We wedged all the framing inside the existing shell.  We made firm attachment to the floor, but kept our attachments to the steel to a minimum. Any penetrations through the structure could result in water intrusion over time.

Cargo Shed – Purchase

Cargo Container Delivery

Cargo Container DeliveryWe did a lot of looking around and finally settled on a shipping company that sold their excess inventory direct to private parties.  Delivery was about five hundred dollars and it took a few weeks for the size, shape, and color of container that we wanted to become available.

When you order one, you need to specify whether the cargo doors are to be oriented toward the front or the back of the truck. Once the truck arrives, the container will be oriented whichever way it is unloaded.

It unloads like a dump truck, with the whole bed tilting up so that the container slides off the rear.  We positioned one end where we wanted it and then used an excavator to rotate the other end into its final location.

Even though containers are fabricated from Cor-Ten steel, they are still prone to decay if left sitting on the ground.  For our purposes, we installed a thick layer of ballast rock (about 6″ above grade) to limit the containers contact with surface moisture.  We followed up with concrete piers to positively tie the structure down (earthquake insurance).

Cargo Shed – Design

Plan

PlanOur home came without a garage or any other utility space. Being relatively hands-on, we had a need for both a small shop and general storage.  Therefore, once we decided to build the structure from a used shipping container we affectionately titled it  the “Tool Box.”

Shipping containers typically come in 20 ft. and 40 ft. lengths.The local cost for a forty foot cargo container is about two-thousand dollars.  A twenty footer costs about two hundred dollars less.  So in the container world, if you buy a larger one, the second half is essentially free.  We opted for a “high cube” which has an exterior height of nine feet – six inches.  It allows ample headroom inside and space to fur in the floor and ceiling for insulation. When complete, the interior finished space is still over 8 ft. high (we highly recommend going this route).

In order to better utilize the space, we divided the building into three sections.  The center provides an access portal from the parking area to the garden while also providing a covered access area for the two storage compartments.  We kept the original cargo doors and added a roll up utility door on the other end so that both compartments would have light and access from either end.

We added a roof cover to protect the sliding door and add some interest to front the wall.  Tying the building to the fence line helps to visually integrate it into the property.  The large porch (hidden from the road behind the container) extends the utility of the building significantly by providing an inexpensive but dry work area.  Stylistically, the curved roof is fun, but also protects the top from weather.  We took the idea a little further and used the roof to protect a series of storage bunks above the rooms.  Having material sorted, dry and close is perfect – plus it’s extremely compact and can store a wide range of material lengths.

Cargo Shed – Big Picture

Containers

ContainersDue to the trade imbalance, cargo containers have been piling up in the US for decades.  You can now purchase a decommissioned shipping container for less than the cost of scrap steel.  Since we live close to a port city (Seattle), we decided to make inventive use of this “waste” material.

Those of you following the current trend in modern architecture have seen a dramatic increase of cargo containers in residential applications.  This typically costs a lot more than people realize.  Their modest width and lack of amenities require numerous upgrades and the skills to work with steel that are less common in the construction trades.

They are, however, an amazing resource – one that we believe is better suited to utilitarian support buildings.

Containers are durable, simple, modular, and movable, so they can endure a great amount of negligence and adapt to changing circumstances easily.  The challenge is mainly aesthetic.  To most, they are an eyesore and parking one in your yard amounts to an immediate deduction in your property value (and your neighbor’s good will).

The challenge, is how to retool a shipping container so that it looks integrated into your environment?  Furthermore, how do you do so inexpensively?  Finally, how do you adapt them to the needs of everyday use rather than the specific needs of shipping material?  These are the questions that we set out to answer.

Photo credit:  Wikimedia Commons