By Dr Alice Nabatanzi
Since time immemorial, timber is one of the many plant products used around the world in building construction, in buildings both large and small. Here we consider timber for the construction of buildings of six or more storeys, and the biochemistry and chemistry of wood modification that could enable much larger buildings. Thus, wood is the oldest material used by humans for construction after stone.
Despite its complex chemical nature, wood has excellent properties which lend themselves to human use. It is readily and economically available; easily machinable; amenable to fabrication into an infinite variety of sizes and shapes using simple on-site building techniques; exceptionally strong relative to its weight; a good heat and electrical insulator; of increasing importance; and a renewable, biodegradable resource.
Whereas wood is an exceptional construction material, we do well to think outside the box in order to appreciate its qualities. There are many more unexploited materials from plants which can be employed in building construction. Plants are made up of phytochemicals (plant chemicals). These are usually manufactured by the plants and some are given off as plant by-products. These plant molecules have been highly exploited and have found great application in the food and drug industry.
The construction industry especially in Uganda has not fully exploited these molecules. Most of the nation’s construction engineers are well-versed with wood or timber as a construction material. The rest of the materials used in building construction are either imported expensively or bought from the local manufacturers dearly still. Thanks to 8M Construction Digest for this great opportunity to enlighten our construction engineers and assure them that plant molecules other than wood are good constructions materials. If other industries have made good use of these materials it is high time the construction engineers got on board.
Let us come back home! Uganda has a high plant biodiversity which can provide solutions to various problems in the construction industry if well researched and developed. Why limit ourselves to wood? How about binding agents? How about sound-proofing materials? The list is endless if we went on to research and break the spell of ignorance concerning what plants can offer in building construction. Apart from the chemical and physical properties of the different plant materials, economic consideration is a must before choosing the best construction material. If you look at the economics of plant materials in construction, you will find that no other material beats their affordability. Look at the steel and iron materials that are imported expensively or bought expensively from the few local manufacturing companies. Have you ever wondered why the local Ugandan man or woman cannot afford proper descent housing? The answer is right here: construction materials are troublesomely expensive. Do not talk about land! Many Ugandans have and own land, some owning a whole village. Unfortunately, the majority die without putting up a reasonably descent house. We have the solutions but have not exploited them.
Therefore, the solution to expensive and inaccessible construction materials is right within our compounds, backyards and neighbourhoods. Plant construction materials are available, accessible and affordable. If incorporated into Uganda’s construction industry, better housing and sustainable development are an assurance.
In the successive features I will:
- Talk about the different non-wood/non-timber plant materials that can be incorporated in the construction industry
- Discuss details of their physical and chemical properties that make them a better option
- Talk about the different plant species in Uganda that are sources of these non-wood plant materials: What is their composition? Where do they grow and how?
- Discuss those non-wood/non-timber plant materials that have already been bioprospected world-wide and found to be applicable in the construction industry
- Conclusively discuss the economic potential of these materials vis-a-vis the imported contemporaries which serve the same purpose in construction
At the end of all these series, we will have broken the tip of an iceberg. The remaining part will be to research and exploit the potential of what we have to solve problems in construction.
Dr Alice Nabatanzi is a lecturer in the Department of Plant Sciences, Microbiology and Biotechnology in the College of Natural Sciences, Makerere University, specializing in plant chemistry, her PhD having been in phytochemistry and neutraceuticals