Living Walls

I love the research Matt Brook and Walter Cicack are doing on creating new building concepts. They have redesigned the brick into something that supports green life. Matt and Walter are part of a class in Eugene, Oregon that studies and develops new ways to build green. Through their experiments, they discovered a type of soil/cement combination that would be strong enough to support itself while porous enough to allow for growth of succulents right in it.

The Earth Bank living wall system has now been installed on a shipping container as a demonstration of the project at the Eugene Federal Courthouse Garden. The wall is 3″ thick and has been preplanted with sedums. The goal of the project eventually is to see whether seeds will be allowed to germinate and thrive in the vertical concrete/soil environment.

They did a few test pours of the soil/cement combination in three rounds. They’d finished 16 test blocks in the first two rounds of test pours and armed with the knowledge from those pours, they were able to find a winning combination in the third round. They wanted the wall to be light enough to mount on the shipping container, strong enough to hold it’s shape, and be fit to support plant life.

They experimented with planting a variety of sedums and hearty native grasses in this test block. In the picture, the block is nearly five weeks old and all of plants planted in it were still alive and doing well.

Test living brick

They acquired a reinforcement screen mesh from Bring Recycling Center for a few dollars. They 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.

Metal support for hanging

Before pouring the mixture, they prepped the formwork by installing dozens of hemp threads through the formwork to tie the two layers of earth bank together. Recycled plastic grocery bags served as a form release. The formwork held a total of about 25 cubic feet of Earth Bank.

Prepping the forms

After pouring the first slab of the Earth Bank wall they scraped off all the excess in order to form a clean flat surface to lay the mounting frame on. They 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.

First form filled

After the second pouring, they quickly set about the work of planting our sedums into the top slab of the Earth Bank. They had collected about 30 lbs of various sedum species to be used. They had to work fast because the Earth Bank started to cure quickly. Within just 30 mins, it was becoming painful to dig into. They kept some space in between the sedums to allow room for seeds to germinate and cover the wall.

Second form filled and the planting started

They used excess plywood to cover the plants to protect them from the heat while they got established. Their tests showed the plants would be fine without the cover, but they weren’t taking any chances.

The newly formed wall covered to protect the plants

The living concrete wall

The only catch they ran into was when they removed the formwork after they’d hung it. The hemp had not successfully adhered the back slab to the mounting system and as a result had to be removed. The front slab did adhere, fortunately, and is supporting all the sedums just fine right now.