Interview with Mrs. Neelam Manjunath, CGMBT on bamboo as construction material
Every year we pay lip service to environmental causes by earmarking special events like Water Day, Earth Day, Environment Day, Wildlife Week, Vanamahotsav etc. Earth Day is celebrated or observed on 22nd April every year, so we thought of touching chords by sharing something truly inspiring: Bamboo as construction material. With Government of India recently approving bamboo as construction material, it paves the way to revolutinise construction industry and real estate business by drastically reducing costs, and moreover in the COVID era it affords us more space by reducing costs and literally giving us healthier atmosphere. Malini Shankar of Digital Discourse Foundation caught up with Mrs. Neelam Manjunath, of Centre for Green Materials & Building Technology in Bangalore. She is a leading voice advocating usage of Bamboo in the construction industry. Here is our expert interview for the Earth Day 2021.
1. What are the indigenous earthen materials that will do well in the construction industry?
The main indigenous earthen materials that are doing well in the construction industry are stone, mud, bamboo and local wood. Another novel locally available material is all kinds of waste that can be recycled.
2. How reliable are they in terms of safety?
They are as safe as any other material. The only catch is people use them like other material, and that is where the problem starts. For example, people want mud to be like cement, or bamboo to be like steel. They have to be used with their properties in mind.
3. Can bamboo be used as ersatz pillars?
Yes very much so, but it depends on the type of building, no of floors and accompanying specifications. It will also depend on the species and quality of bamboo available. It is not advisable to use it without proper professional guidance. Since they are not factory produced with precise specifications like steel etc, people with experience should be consulted.
4. What are the advantages and disadvantages of using earthen material in the house construction industry?
The advantages are that they are healthy materials both for man and nature and with excellent properties for construction . They are biodegradable. The biggest disadvantage is that it is biodegradable, so have to be protected from extreme exposure to the elements. Another disadvantage is the social stigma attached with them and they have no marketing budget. They are valued against the industrially produced materials with big marketing budgets. Their advantages are never brought to light and there are no budget allocation for skill development for this sector.
5. Fly ash based cement blocks maybe eco friendly on account of its sheer recycling value but it does not quite fit into the category of earthen material like say laterite blocks, or adobe. Your comments please.
Flyash is a waste from the power industry and it is good that it is being recycled in place of going to landfills. Lot of waste from several industries can become the raw material for another industry. Nature recycles all its waste, isn't it?
6. Fly ash or cement locks still do not bring the same kind of climate neutral elements into the construction as say laterite blocks, adobe or mortar... please comment.
I think you mean Natural elements. No, they cannot bring the same natural ambience like the natural, local materials.
7. Why has low cost construction not gained the same kind of popularity as other mainstream means of construction? Is it lobbying that’s to blame or not enough publicity to alternate earthen material? Yes, very much so. As I said earlier there is no lobbying for one, policy is another one , calling them a Katcha house. These are not included in SR's and hence people sometimes find it difficult to get loans for these constructions or buyers. Another major factor is that people look for the same kind of performance from these materials like from cement and steel , but they are not ready to pay the price for it. They think this should be low cost construction. Hence most of the professionals working in this sector are economically unsustainable. Due to this problem, the sector has not developed and has remained a niche market.
8. What are the types of buildings that are ideally suited for earthen material construction?
All types of buildings can be done with earthen materials, keeping the above mentioned factors like material properties in mind.
9. Can multiple storeys be constructed with earthen material? Tell us what factors go in favour of its safety and what against?
Yes multiple stories can be made with earthen materials, with the structural design of the construction system keeping the material properties in mind as i said above. They are as safe as any other material. Like contrary to common belief, bamboo and wood are as good as concrete and steel in a fire situation. Stone , laterite and mud has to be used with load factors in mind.
10. Please dwell on the climate neutral values of alternate / earthen material for construction.
Earthen materials breathe and hence their buildings are very healthy from both physical and psychological point of view. They also use least energy to use and maintain.
11. Can treated bamboos be used as pillars in multi storeyed construction considering IPRITI has made a prototype for such construction?
Yes with proper structural systems. I have been associated with IPIRTI for construction with bamboo from 1999 and have done their buildings.
12. Can you tell us a little more about this IPRITI prototype? About its feasibility / cost efficacy and climate neutrality maybe ...?
They have developed a some construction systems with bamboo with testing of the material and some of the joints. These if used have to be done with proper application of these with the present project in mind , not mandatorily. I started my journey with bamboo with IPIRTI. They can do them as research projects only and have to be taken like that. But when one deals with private clients in the open market and with all competition of the building industry, many of these technologies have to be reinvented to suit the client, climate, material availability and other such factors.
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