Since then I have seen more, and the "concept" is fantastic. Here are some things to consider about them:
If the bamboo is not treated with some natural insect/decay inhibitor (very very well) like borates these roofs in most regions where bamboo grows will only last about 3 to 5 seasons before requiring replacement...sometimes in less than a single season for some species of bamboo.
If the bamboo is not large enough in diameter (sometime that doesn't even help) when large monsoon rains come, on pitches lower than 12/12, the water volume exceeds the capacity of the channel to transport it to the eave of the structure.
Overall, a beautiful concept, yet has challenges compared to other systems. Thatch, or bamboo multi layer shingles in a similar format to the one in the photo has less challenges, yet still needs treatment to resist decay, and insects which is a never ending battle in many areas where bamboo grows naturally.
I also never recommend pitches lower than 12/12 for most builds unless using a more durable and water resistant roofing method.
My 2¢ for an otherwise beautiful roof style...
Actually, in the context as shown in the diagram, it is part of a "roof diaphragm" and as such plays a part in the structural load dynamics of a structure. It can be mitigated in some design matrixs to play a less vital roll than usual, yet will still play a role none the less.
As for combustibility, thatch, and other related modalities are no more likely to end up in a conflagration than is sun bleached bamboo stalks. I would also suggest that it is folly to use any organic material with a propensity to burn that does get treated with one of the many inert and nontoxic fire suppressant washes...
As for replacing a structures roof every 10 year, compared to much more durable and longer lasting modalities, I think many would find both logistically, and economically wasteful. I know as a professional builder, that my clients would be very disturbed with me if I designed buildings that only had roofs that lasted 10 years before needing replacement......even on small garden sheds, this would be an issue for most DIYers I know. Yet, I will grant this is an individual choice if such work isn't perceived as an issue...
I love all the wonderful ideas and concepts folks share on the internet about natural building. I also understand that a lot more "romantic views" about these materials are projected than tangible views understood and the logistics that actually comes from working with them, designing with them and building sustainable and enduring structures with them. I am more than open if someone cares to "experiment" or try an "I think ideas," yet it is in my nature, and I feel a certain obligation as a teacher and professional in the field to always illustrate all aspects of a "conceptual plan," and what parameters come with it.
If you like this roof, and can afford to replace one every ten years, and "think" it will fulfill your needs...I am 100% behind whatever you would "like to try" ...
Jay C. White Cloud wrote:
I also understand that a lot more "romantic views" about these materials are projected than tangible views understood and the logistics that actually comes from working with them, designing with them and building sustainable and enduring structures with them.
I definitely agree with that. In all honesty I will be living in a conventional home but for sheds and other outdoor structures I will potentially experiment with this.
Personally I wouldn't use bamboo on the roof of anything more substantial or durable than a garden gazebo or patio shade, something easy to strip them off and replace.
Despite living in bamboo areas none of the roofs of houses in the parts of China I saw had bamboo roofing, through roadside stalls and lean-to shacks had them.
If it's not good enough for those who have lived with the material for centuries, why try reinventing the wheel?
That was an excellent suggestion and perfect segue into some aspects of what many are "trying" to achieve with natural materials...
This forum, and many of us on here, be it DIYer first timer-backyard experimenter, or experience natural builder, all seem to fall within a spectrum of understanding and/or application:
"Traditional Natural" (TN)
These architectural modalities are at minimum hundreds of years old and in most archetypes...thousands. Earth, stone, textile, or timber, these methods have an empirical understanding usually rooted in indigenous vernacular forms suited to specific regions or biome types. The actual methods of construction are either still known today by some "knowledge holders" or are documented and studied thoroughly enough to extrapolate over 95% of the original intent of the orgin creators. In these vernacular forms the means, methods and materials (MMM) are employed in a well understood context of application, as reflected by history for the elemental and structural proper use and implementation of a given design matrix.
"New Age Natural" (NAN)
These are the current "reinvented" or "experimental" concepts of what natural materials may be able to achieve, while they are usually augmented with elements of modernity. Most, if not all of these, are extrapolations or alternate applications for most if not all of the MMM found in TN building systems. With few exception, most can be found rooted in history of vernacular architecture and building systems. These contemporary methods are only in the "testing," or "I think it will work this way," stages of development, as are most reinterpretation, experiments, and reinventions of any pre-existing modality.
Another way of examining this is the difference between "permanent" and "transient" types of architectural opus in context to MMM. TN construction methods can be relied upon (within reason of proper application and maintenance) to last a very long time, while the NAN systems could be construed, or have clearly reflected being of a transient nature, and probably not best practice for dependable mainstream residency or reliability. As such, any time we take a TN method and reinterpret its orgin application/use we are facilitating a NAN method and risk the inherent pitfalls with in.
Thanks Rhys and Amedean for helping me get that thought coalesced and out of my head... It actually belongs in Reasons to change or not change Natural Building Systems so I shall post it there as well...thanks again for stimulating this connection.