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Introduction

Abstract

We are a group of four Environmental Science Students who constructed a shingled yurt roof by reusing old cans that would have otherwise been thrown away or recycled. This project was done for our client CCAT(the Campus Center for Appropriate Technology) as part of our Engineering 305 class. Our goals in creating this roof were to rescue resources from the waste stream and to create a functional roof to meet CCAT's specifications.

Background

CCAT is the Campus Center for Appropriate Technology at Humboldt State University, in Arcata, CA. CCAT built it's yurt to provide a demonstration of a sustainable housing structure. Yurts were originally built by nomadic peoples, and traditionally constructed to be mobile; this is not true of the CCAT yurt. The CCAT yurt was built to be a permanent structure on campus and was originally built with redwood shingles as its roofing material. When CCAT changed locations in 2004 this roof was replaced with a "weather proof" canvas roof. Unfortunately, in Humboldt County canvas rooftops often don't hold up to the elements. When this project came to us the CCAT yurt had a dangerous, black mold infested canvas roof. Our goal was to replace it with a water resistant, structurally sound, recycled roof. Recycled materials are a great product for roofing because many materials that are thrown "away" still have the capability to be used as something functional.

Problem statement

The objective of this project is to creatively utilize recycled materials to produce a safe, durable, and aesthetically pleasing yurt roof. We want to satisfy CCAT's vision for the yurt while focusing on creative reuse in order to both educate visitors and restore the structure to a functional state.

Criteria

The following criteria will be used to determine which roofing options will be best suited for this project. The scale is from one (least important) to ten (most important).

Criteria	Constraints	Weight (1-10)
Durability	can withstand >/= 38in annual rainfall	9
Level of Maintenance	requires less than 1 hr a week	6
Aesthetics	Must receive at least 1 compliment per day	4
Educational	Must provide recognizable visual information about green building	6
Safety	must be safe for people to enter yurt	10
Functionality	keeps water out of structure for >20 years	9
Environmental Friendliness	uses at least 50% recycled or reclaimed materials	8
Budget	Must not exceed budget set by CCAT	8

Literature Review

This is a review of some of the available literature on lighting and roofing material pertinent to the yurt re-roofing project at CCAT. The CCAT yurt is a freestanding structure with minimal wiring or electricity. In the past, light was emitted into the building via the white canvas roof. Since that roof has molded it is very dark inside. Because the yurt relies on the roof for light integrating a mold-resistant skylight will be essential.

Roofing Basics

Types Roofing Materials

Aluminum

1. Aluminum cans are light weight, highly reflective, non-toxic, non-pyrophoric, and are easily fabricated. Aluminum also has a high resistance to corrosion due to the invisible oxide skin that forms when it is exposed to the atmosphere.^[1]

Recycled Tires

1. Race slicks have been used to make tire shingles by simply cutting the tires with a razor blade, to the desired shape, and screwing the pieces onto plywood this method would be adapted from the methods used on Tire shingles.

Living Roof

Green roofs or living roofs are beneficial not only in their aesthetic appeal but in their environmental benefits of carbon sequestration as well as reflecting more incoming radiation than a traditional roof. Green roofs can actually last longer than traditional roofs, which actually age and reduces in durability when exposed to heat. Bare roofs absorb incoming radiation during the day and increases the temperature, in comparison to a green roof can reduce the temperature of the roof by 45 degrees in some cases. The slope of the yurt roof is suggested to be no steeper than 2:12, which is equivalent to 9.5 degrees, this is what could be the determining factor of any sort of green roof because it is so steep.^[2]

1. Moss grows naturally on roofs made of concrete or wood
2. Native forest floor species

Redwood Shingles

Redwood shingles were on the original yurt roof before CCAT was relocated and the yurt was disassembled. The prior shingles are long gone but new shingles could be made.

Lighting

Lighting Concerns

Arcata, Ca is an area which on average has a less than 50% chance of experiencing a sunny day.^[3] This means that a passive solar daylight system must be designed with this in mind. According to Helmut Köster in his book on daylight architecture, it is possible to capture enough light from the sun if the skylights and windows are placed appropriately.^[4] Visual appeal is also important, both on the interior and exterior of the yurt.

Lighting Options

There are several ways to create day lighting that maximize the availability of the sun's light. Solar tubes are a very popular method of natural lighting, and can provide very strong focused light through refraction and reflection of the light via mirrors and lenses inside a tube^[5]. This same (though less dramatic) effect can be created through the use of old plastic water bottles filled with water which is able to refract the sunlight as well^[6][7]. Skylights do not have the same capacity to intensify the sun and capture as much of it, and rely more strongly on clear skies and proper placement, this makes them a less desirable option for the yurt project^[8].

Visuals

If the plastic bottle solar tubes were to be used it would be an added benefit to enhance their visual appeal in the interior of the yurt. Susan Wasinger outlines in her eco-craft book several lamp-shade type projects highlighting creative reuse which would be appropriate, assuming the bottle-bulbs provide enough light.^[9]

Water Resistance

In order for the roof to remain water resistant we have two options to experiment with. The first is penguin plastic, mostly used for hydroponics as a reflective yet opaque water resistant and tear resistant layer. The second experimental option is ironing plastic bags, an idea adapted from FBP Hot Dang Plastic Encasement.

Black Mold

Black mold, stachybotrys chartarum, is one of over 100,000 types of fungi that grow on organic materials and commonly found in homes. All types of mold produce spores that travel through the air until they collect on a damp surface and reproduce. [[1]] Although mold is predominant in our environment, there can be major health problems associated with inhaling large amounts of spores when indoors. There are three processes in which mold affects human health: Allergy, infection, and toxicity. [[2]] Black Mold produces a harmful toxin known as mycotoxins that can lead to death. [[3]]

Construction

maintenance

We wanted there to be very little need for maintenance of the yurt roof. Every seven years new water will need to be put into the bottles in the roof. The bottles slip out of the top of the flashings. If a shingle breaks off, read above process on how to construct a new one and there is paint left in the CCAT shed. Use a staple gun to attach to the roof.

Tentative Timeline

Project	Started	Completion
Complete trial designs	February 20	March 1
Present designs to client	March 5	March 5
Decide on final design	March 8	March 8
Measure roof area	March 8	April 1
Remove hazardous mold tarp	March 15	March 15
Find cans and make 600 shingles	March 8	May 1
Purchase plywood	April 24	April 24
Saw plywood	April 24	April 24
Rent nail gun and air compressor	April 25	April 25
Install plywood	April 25	April 25
Obtain and apply roofing felt	April 30	April 30
Rent staple gun and air compressor	May 1	May 4
Install tin shingles	May 1	May 4

Costs

Quantity	Material	Source	Cost ($)	Total ($)
10	10'X6' plywood boards	Arcata Lumber	30.00	300.00
2	Rolls of organic roofing felt	Arcata Lumber	30.00	60.00
600	# 10 Industrial sized food cans	HSU cafeteria, Big Louie's Pizza, Wildberries, other local restaurants	Donated	0.00
24	Cans of rustolium paint	Arcata Lumber, Ace Hardware	4.95	118.80
16	Flashings	Arcata Lumber	10.00	160.00
16	Coca cola bottles with corks	CCAT	Donated	0.00
3 days	Rented nail gun/staple gun with air compressor	Don's Rent All	65.00 per day	195.00
Total Cost				$833.8

Conclusion

Team

names

User:Lily Brook

References

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