Sandbags have been in the news recently, we have seen them piled high as a desperate measure to help contain the devastating floods that have been plaguing Ireland in the past few weeks
Coincidentally, in the midst of all of this, my brother Graeme Labe who designs and develops Eco Tourist safari camps around the world, sent me some images of a project in the Serengeti Wildlife Park that he designed using sandbags as a construction material.
The idea of using sandbags as a construction material for ordinary housing is fairly new. It was developed as a complete building system over the past fifteen years in South Africa as a cost-effective way to assist South Africa in its endeavour to house millions of homeless people. (Construction costs can be reduced by up to 40%). It has since gained currency amongst people looking for an environmentally friendly alternative to conventional building practice.
I have recently been in touch with Rodney Wall, a South African Eco Home specialist, He is passionate about the benefits of this building system, he has used it on many builds and community projects and is working on creating a totally carbon neutral system. Both he and Graeme believe the this method of building is suitable for all climates including Ireland.
Could it work for The 5k Extension?
Well, I could haul in all of you who have offered to help to do most of the tough work by filling sandbags!
Graeme has a concern about the lack of sand freely available on the site and the ensuing costs of having to buy sand, but I reassured him, by pointing to the fact that so many builders and landscapers discard so much sand to landfill in Ireland. We would just need to put the word out that we would happily take their leftover sand rather than them having to pay to dump it.
The biggest negative in using this method for my project is the width of the walls which are thicker than brick. Because the space in my back yard is so tight, I am looking for the thinnest possible building material.
Rodney Wall of Eco-Steps outlined the benefits of sandbag building to me.
Benefits of the Eco-Beam Sandbag Building System
- Excellent thermal stability. Due to its high thermal mass, the structures are cool in summer and warm in winter. Millions of small air spaces between the grains of sand are responsible for good thermal insulation.
- Superior sound-absorbing properties which help to provide a measure of privacy in close-quarter living or within the house between rooms.
- Breathable, vapour permeable, “natural” walls for comfort and healthy living
- Wind and water proof. The security and fire protection properties of the walls are also excellent.
Reduced Construction Costs
- The weight of the construction materials makes transporting easier and cheaper while allowing for construction in areas without adequate road infrastructure. (e.g. 1,500 eco bags can fit in the boot of a car; this is the equivalent of 4,500 bricks).
- Unskilled labour can be used to fill and stack the sandbags, further reducing labour costs.
- Reduced construction time
- The only “wet” trade is plastering and no mechanical tools, equipment, skills or electricity is needed on site.
- Most specialized trades like electrical and plumbing can be completed concurrently with the initial build, further reducing construction time.
- Minimal building waste or losses on site
Reduced environmental impact
The system has a low carbon footprint, as very little energy is consumed in the process of designing, manufacturing or building a kit.
- The carbon dioxide emission of one square meter of sandbag wall is more than 95% less than that of a conventional brick wall.
- On site construction requires no mechanical or electrically operated equipment.
- Sand can be found locally nearly everywhere around the world, in some regions even directly on the construction site.
- The energy required for making the polypropylene bags can virtually be negated as the bags are very thin and contain a small amount of raw material.
- The same is true for the steel used in the manufacture of ecoBEAMS.
- If natural material like hemp is used for the bags instead of a geo-textile it can be reduced even more
- There is no energy consumption as in producing bricks or producing cement
- If natural material like hemp is used for the bags instead of a geo-textile the carbon footprint can be reduced even more.