Wednesday, August 11, 2010
Beginning with the concept of an “Urban Art Green Wall,” this investigation into the graphic interaction between man-made designs and organic plant growth has taken on the new title of “Grow More.”
This system incorporates a graffiti spray-painted canvas of fibrous air filters that covers a vertical living wall assembly. Pillows of soil/seed-filled felt and mesh are suspended with horizontal strips and watered by an integral drip feed system. As the seedlings sprout, they extend through the embellished filters to produce leaves and flowers further enhancing the visual composition.
The combination of a rain screen and a planted component, without a water/airproof membrane, allows the system to function as a breathable wall and act as a heat sink for the interior space. The majority of exterior rainfall is shed off the face of the air filters while allowing for air vapor to reach the soil pockets behind. Allowing for more control over the moisture content, a drip feed tubing line is woven through the pockets to hydrate the soil mix. From the interior, the moist felt and air movement work to lower the ambient temperature through evaporative cooling.
Brian Carter – Summer 2010 – Horticultural Building Systems – Univ. of Oregon
1. The construction began with laying flat a sheet of felt fabric on top of horizontal 1.5” x ½” x 70” furring strips spaced every 10” on center.
2. Next, a mix of peat moss, pumice, fertilizer, wildflower and morning-glory seeds is piled in 8“ rows between the furring strips beneath the layer of felt.
4. The fabric and furring construction is then applied to the vertical surface, felt to the back, by attaching 2” screws through the (2) furring strips into the wall studs.
5. A drip feed line is fed along the horizontal spaces behind the face mesh layer and switches-back with every horizontal soil pocket.
6. Vertical furring strips are then attached to the horizontal slats. These will be used to attach the air filters in a uniform surface.
7. Next, (12) 1” x 20”x 30” Cut N Fit Air Filters are arranged on the vertical surface and attached with 1.5” lath screws.
8. The final surface embellishment is applied with nontoxic spray paint. The text reads “Grow More” and follows the style of urban graffiti art. The next graphic iteration will result from plants growing through the air filters.
Final: Midori Yane - A Japanese-inspired tiled green roof by Amanda Loomis, Crystal Morrison and Jennifer Purcell
Interdisciplinary work in Landscape Architecture:
Our professor, Richard Hindle gave us the artistic license to incorporate our personal interests into this green-roof studio. We took the idea and ran to the University of Oregonʼs Ceramic studio. Through the term, we learned a tremendous amount by designing and building a unique green-roof system that we will be share with the community for years to come.
Introduction to the ceramics studio:
The resources and helpful hands at the Ceramic studio allowed us to build and fire more than 50 stunning tiles in about four weeks time. The extruder pumped out around 250 lb. of clay in the form that we needed our tiles to be.We became masters of a skill that is used to connect two pieces of clay together called slipping and scoring.
The slipping and scoring process includes a tool with the ability to scratch the surface of wet to semi-dry clay, slip (slurry clay, you can find it at the bottom of your clay bucket while throwing on a wheel) applied to the scratched area, and the act of “shimmying” or pressing the two pieces together.
Each ceramic piece was scratched and slipped; the tiles; due to the size of the extruder, the Kawara or end cap, and the sunflower. Ceramics takes a lot of attention to detail, we spent many long hours propping the tiles to keep their shape, waiting for them to dry to scratch and slip them or hurrying to connect them before they were too dry. Many considerations must be taken into account when dealing with a large project such as our green-roof. For example, we had to make many parts of the ceramic roof at the same time because they must be at the same consistency to avoid cracking and different shrinkage rates. Something we did overlook was the shrinkage of the tile as a whole through the firing stages. We designed the wooden roof structure holding the ceramic tiles to the width of eight clay tiles. However, when we manufactured the tiles, we measured them to a known dimension, wet; not taking the firing shrinkage into consideration. Consequently, after the firing process, we were left with a small uncovered portion on the right side of the roof. Overall, the attention to detail paid off and our roof is a success.
The kiln that fired our 50+ tiles is named Olsen. This large gas kiln helped us make the ceramic tiles with no losses or damage. It was the first time for any of us to experience the world of the kiln. The first firing is called bisque. After shaping the tiles and letting them dry, we loaded the kiln.Cheri, a friend who has experience in the ceramic lab extended her time to help us (thank you Cheri!) fire our tiles. We candled the kiln allowing the atmosphere and the clay to reach an even and warm temperature for six hours.
The firing took another six hours and the entire process consisted of a sixteen hour day in studio. Although it was intense, the knowledge that was gained is something to be grateful for. Olsenʼs temperature was gauged by taking out one of two brick pieces from peep holes.
After blowing in the kiln to reduce smoke, small cones of clay that melt at different temperature were analyzed. Our red terracotta clay body melts at cone 06 temperature; therefore, when the cone before cone 06 melts, we know that the kiln is at the proper temperature (around 1800 degrees) and we may turn off the kiln.
After the bisque firing, we then glazed the tiles using a clear glaze. First, portions of the tiles that will be in contact with the kiln are waxed to prevent glaze from sticking to the tile and kiln board. Next, the tiles are evenly coated with glaze. The clear glaze mixture is a green color prior to being fired. Once glazed, the kiln was loaded up again for a second firing. We had made extra tiles to allow for loss and breakage in the two firings. However, we were incredibly lucky to not break a single tile. We opened the kiln for the final time and were rewarded with a full kiln of unbroken and beautiful tiles.
Roof Frame Construction:
The wooden add-on roof frame is a fairly simple, yet elegant construction plan. We started by making all necessary cuts using a cut list. Constructed at a 4/12 ratio the supports were cut to fit the space exactly.
All four 2x6 supports are lag screwed into the 2x4 studs which are in turn, bolted through the metal ribs of the storage container. Prior to installing the tiles, we all hung off of the roof to verify that it would hold the weight of the tiles/soil/plants (approximately 150 lbs.)
The roof surface was prepped with #30 roofing felt; 1x2 inch nailing strips were then installed horizontally on top of the felt. Each tile was screwed to the strip at the top of the tile through a hole that was created while the tile was still soft and before firing.
The decorative end cap was designed to be attached using screws. However, the shrinkage from firing made our pre-drilled holes for the end caps not line up properly with the eave tiles. This was remedied with innovative thinking and the use of sturdy wiring.
Each tile is designed to interlock to the tiles on its left and right. The installation process was very much like a giant ceramic jigsaw puzzle; many pieces had to be swapped in and out to find the perfect fit. We truly came to appreciate the technical specificity involved in large scale manufacturing that results in consistently perfect tiles.
As part of the shrinkage issue, the gables needed two inches of clay removed on the outside of the tile to allow the tiles to sit on each other when they overlapped the roof. We cut the tiles using a makeshift wet-saw: a Dremel and water bottles. By cutting a small piece off of the gable tiles, we were able to mostly span the gap.
The final step in finishing our green roof was plant installation. The growing medium used is a 75% mineral 25% organic mixture. This mixture reduces the weight dramatically compared to a typical potting mix with high organic matter. Drought tolerant plants were chosen due to the small volume of growing medium, the minimal availability of water and desire to create a sustainable structure. We planted Hens & Chicks, Rosemary, Creeping Thyme varieties, Sage, Blue Fescue, Ajuga, Ice plant and a variety of sedums.
We hope that you have enjoyed learning about our roof fabricating/building process as much as we enjoyed doing it. We hope that we will have future opportunities to design and create something this beautiful again soon.
Rich: Thank you for the opportunity, instruction and support that you gave us. We couldn't have accomplished something as ambitious as this without your instruction.
ADDITIONAL STORMWATER INSTALLATION
Tuesday, August 10, 2010
The Earth Bank system has been successfully installed on the shipping container at the Eugene Federal Courthouse Garden. The final result was a concrete wall 3" thick supporting the living needs of various sedums. Time will reveal weather or not the Earth Bank can successfully allow seeds to germinate and thrive.
When we published our midterm post we had just finished our second round of test pours for the experimental Earth Bank mixture. As we were pouring our third round of experimental mixtures we had the idea to use the Earth Bank as a direct potting soil for starts and sedums rather than just seeds (as the project was originally conceived). This allowed us to increase the viability of the project by allowing it to support green life from the start. The seeds became a secondary feature intended to "fill out" the negative spaces left over by the sedums.
Our third round of test pours was highly refined with data collected from the first sixteen test blocks. In the third round we finally stumbled upon a mixture that seemed to be working- it was lite enough to be mounted on the shipping container, strong and stable enough not to fall apart and suitable as a living matrix for plant life. This is what our successful test block looked like:
As you can see we experimented with planting a variety of sedums and hearty native grasses in this test block. At the time this post was published, the block was nearly five weeks old and all of plants planted in it were still alive and thriving.
With a workable Earth Bank mixture selected, it was time for us to construct the mounting bracket and internal reinforcement for our living wall.
As the diagram above illustrates we designed the mounting system to be constructed of 1" wide x 1/8" thick strips of standard A36 steel and to be joined together using nuts and bolts rather than welding (because neither of us knew how to weld and the fabricator's estimate for the job was over $350). We acquired the steel from Coyote Steel here in Eugene and went to the EMU craft center to begin fabrication.
We drilled all the holes into the steel and then proceeded to fabricate the frame using a vice and hammer. The system was very simple as we had engineered it to have only 90 degree bends. Having bend and drilled all the steel to spec we then laid the frame out and bolted it together.
We had acquired a reinforcement screen mesh from Bring Recycling Center for a few dollars. We cut the screen to size and then installed it onto the frame using the nuts and bolts at the intersecting verticies and zip ties on the lengths.
We left the tails on the zip ties sticking up out of the frame as added horizontal reinforcement for the Earth Bank Mixture. We are glad we made this decision for reasons we will elucidate later. With the mounting and support frame constructed we took it out to the site and tested our mounting system on the shipping container to be certain that we had a workable mounting system.
Having drilled all the mounting holes and satisfied ourselves that the mounting system would work as engineered we set about building the formwork for the final pour of our Earth Bank wall. We went to the Lawrence woodshop to do this work. We constructed the formwork out of split 2x6s and a large piece of 1/4" thick plywood that was lying unused on the site.
With the mounting system and the formwork completed we took the project to the site to begin mixing and pouring the Earth Bank. We borrowed a cement mixer form UO Architecture Professor Stephen Duff which gave us a big advantage and made the whole job a lot easier.
Before pouring the mixture, we had to prep the formwork. We began by installing dozens of hemp threads through the formwork. the idea behind the hemp threads was that they would run through the width of the two layers of Earth Bank tying them together and to the mounting bracket.
We then needed to install some sort of form-release into the formwork. Recycled plastic grocery bags worked reasonably well when we did our test bricks, so we decided to use this method again. We installed the plastic bags into the formwork with a staple gun and then cut holes in the bags to allow the hemp twine to stick through.
We then began to mix the Earth Bank mixture in the electric cement tumbler and pouring the mixture into the formwork.
The formwork held a total of about 25 cubic feet of Earth Bank, but the cement mixer could only handle about 6 cubic feet at a time so we ended up pouring the layers of the Earth Bank in several stages. We had to work quickly however, because the Earth Bank mixture begins to dry and cure rather quickly and we needed it to still be wet when we were done so that we could plant into into.
After pouring the first slab of the Earth Bank wall we carefully scraped off all the excess in order to form a clean flat surface to lay the mounting frame on. We carefully pulled the hemp twine all the way through the first slab and laid them on the side of the formwork so that they could also be pulled through the second (top) layer of the slab.
With the first slab poured and prepped we carefully laid the mounting frame into the Earth Bank and pulled all the hemp twine through to the other side.
We then laid the top layer of the formwork over the bottom formwork and the mounting frame.
After three more rounds of mixing with the cement mixer and careful pouring, the top slab of the Earth Bank was prepped. We then pulled the hemp twine through the top slab and carefully set them aside. We did not scrape off the excess material of the top slab because we felt like a more rough, earthy look would be more aesthetically appropriate than a smooth flat surface.
Next, we quickly set about the busy work of planting our sedums into the top slab of the Earth Bank. We had collected about 30 lbs of various sedum species from our own back yards and those of our colleagues; we had several varieties, many of them in full flower.
The Earth Bank began to cure quickly and become cumbersome to dig and plant into so we recruited the help of some of our classmates on site to help us do the planting before the Earth Bank got too hard to manipulate by hand. With their help, we managed to have all the sedums planted into the Earth Bank within a half an hour, the job was done just as the Earth Bank was becoming painful to dig into. We chose to space the sedums apart by 2 or 3 inches in order to give plenty of space for our grass and wildflower seeds to germinate and grow. The idea with the plant spacing was that the sedums would provide an attractive living green aesthetic right from the start and the grasses and wildflowers would slowly grow into the negative spaces in between, the hope being that eventually the whole Earth Bank would be covered with vibrant living plants.
With the Earth Bank planted and prepared for drying, we placed some old scraps of plywood we found at the site over it to keep of excess sun and heat while the plants were in their most vulnerable state. Even with the data from the successful test block telling us that the sedums could withstand full sun during the curing process and pull through just fine, we wanted them to get a good opportunity to settle into the Earth Bank before exposing them to full sunlight.
The Earth Bank was allowed to sit and cure in this state for a week before we took any more action. The next thing we did was tilt the Earth Bank up into a vertical position and remove the plywood backing to the formwork in order to give the Earth Bank a good chance to cure thoroughly all the way through. We propped it up with some scraps of wood that we screwed into the side of the formwork to create makeshift knee-braces.
With the Earth Bank propped into an upright position and the plywood backing removed, we removed the plastic bag form release from the Earth Bank.
After allowing the earth Bank to continue curing in this position for another several days we were ready to mount it to the shipping container. In order to give it extra stability while being moved and mounted, we lashed the whole thing together with ratchet tie-downs to hold it firmly together.
The Earth Bank wall we had constructed ended up weighing several hundred pounds (including the Earth Bank material, the steel frame and the side formwork) and having a volume of approximately 25 cubic feet. We were unable even to budge it by ourselves so we requested the assistance of several of our colleagues and our professor. It ended up taking 8 people to get it off the ground and move it into position.
As our colleagues held it stable, we proceeded to mount the Earth Bank frame to the shipping container using standard 1/4" nuts, bolts and washers.
After installing all the bolts and removing the supports the Earth Bank held fast to the shipping container. We were relieved to find that the mounting system we had engineered was sufficient to do the job. We removed the formwork from the top and sides of the Earth Bank.
However, as we removed the formwork from the bottom of the Earth Bank we ran into an unforseen snag. The back slab of the Earth Bank was not adhering to the steel frame the way the front slab was. The rear slab was completely disconnected; our plan to use hemp twine to tie the two slabs to the steel frame was unsuccessful.
As you can see the rear slab was falling down, disconnected from the steel frame, the only thing preventing it from falling on the ground was the bottom feet of the steel frame. Since the rear slab was basically dead weight at this point we decided to remove it. Carefully breaking it apart with hammers and chisels we crumbled it down to a point where it could be slid in between the bottom steel feet and removed from the cage.
We ended up with a pile of wasted Earth Bank that had to be carted off and disposed of.
The front slab did adhere to the steel frame, however. We believe that this is probably due to two factors. First, the front slab had the benefit of the (highly textured) nylon zipties attaching directly to the slab and the steel frame. The zip ties can hold 50 lbs a piece and there were several dozen of them; this may provide some support to hold the slab onto the frame. The other factor may be that since the top slab was poured onto the steel frame and wire mesh it had a better opportunity to envelop and bond with the steel system. Either way, the top slab adhered strongly. In the end, instead of having an Earth Bank that was 6" thick, we ended up with one that was merely 3" thick. We found that this was a pleasing, thinline aesthetic and we were not disappointed with the final result. After all, the most important part of the Earth Bank was successfully mounted and installed.
Since the rear slab was no longer present to do the job, we decided to reinforce the adhesion of the front slab to the steel frame using a simple mortar mix applied directly to the wire mesh and the sectional pressure points of the steel frame.
The final installation of the Earth Bank appears as below.