Hey. My name is Aubrey. I am currently living in Nepal, and working in waste management and recycling.
I have been volunteering on a small model farm / community development project called the Kevin Rohan Memorial Eco Foundation. They have been building houses and buildings using bottle and mud walls, as well as local materials.
We are looking to take these techniques and construct reclaimed material houses in Kathmandu as well as other parts of the country.
I am hoping this forum will be a good place for sharing ideas, as well as gathering practical information.
I have some general questions, that have perhaps been answered on other threads, if so, links would be helpful.
The houses they are building here on the project use a cob like mortar. The ratio is 2:1 sand to mud, and shredded paper is added for structural support.
The walls are 9ish inches think on average. Constructed with open bottles facing either inside or out.
Another small model house has been built. it is roughly 3x3m, and the walls support a bamboo and grass roof.
Does this mortar mixture and wall thickness sound sufficient, or can anyone offer suggestions?
Some other questions I have relate to insulation. Here in winter the temperature hovers around zero Celsius at night. What would the
R value of a typical wall be (open or closed bottles)? Would capping the bottles make a large difference (creating a thermal break), or would filling them with something to create more thermal mass be the way to go?
We are very excited about these projects, and any help is greatly appreciated.
Is there a reason you are not using some of the indigenous timber frame, stone and earth building styles of the region?
When I have some in formation like thisfrom you, and a little more, I can help you design a wall system for yourself, that should be applicable to the region. We can discuss thermal properties and the like once we understand the structures final design and what the thermal wall matrix will be comprised of. In any area which is prone to severe seismic activity, architecture has to reflect that reality. Recycled materials like glass bottles in mud walls could be disastrous if not planned out properly.
Our main goals at this point are to use waste materials and build cheaply. Our organization has a very limited budget.
I am in Kathmandu, working with a waste mamagement NGO, and so bottles and dirt abound, but timber and stone are quite expensive. In other areas of the country i have visited, the indigenous methods make a lot of sense, but with timber scarcity and lack of a close quarry, they are not well suited to my current location.
Seismic activity is always a concern here, but rarely factored into building design unfortunately.
I dont imagine there is an easy way to help earthquake proof this kind of building, but i dont think all the conventionally built brick and concrete buildings would fare much better in an earthquake.
a few more practical questions as well,
in a mud and bottle wall, what is the actual function of the bottles? are they merely place holders, or do they contribute structurally as well?
I understand the constraints of a tight budget, that can make things really challenging. Have you read anything about "earth-bag" structures? You may be able to secure some empty sand bangs in the role from one of the other NGOs. It is a quick way to build a stable structure.
I have not been there in a long time, I understand the much of the architecture there probably will not do well in and earthquake, and you're correct about concrete. I try to never use it and if I do, it is sparingly.
Most structures, actually, can be greatly improved for earthquake if attention to design detail is applied with a seismic event in mind. The glass bottles, for the most part are a simple form of fenestration and artistic expression. They can very much be a liability in an area like yours.
I did have one of my students that I taught timber framing to travel there. He found stone, clay and timber but he was is in the "know," for that kind of architecture. Maybe if you talked to a sawyer/timber merchant, it could give you some ideas, they often have stock at reduce pricing that would not meet market quality.