|Using local materials for fencing constructions|
|Ecologization - Peoples Eco-Life Project|
|Wednesday, 30 September 2009 08:39|
USING LOCAL MATERIALS FOR FENCING CONSTRUCTIONS FOR LOW-RISE HOUSING DEVELOPMENT IN UKRAINIAN CONDITIONS: CONCLUSIONS FROM COMPARATIVE ANALYSIS
Using local materials such as thatch, rush and so on has been often done in house building in Ukraine since old times. Human beings were using first what is near by. People have a great experience in using these materials and on their basis create extremely advances and reasonable building techniques which are adapted to specific conditions.
Nowadays using local materials is reasonable for same reasons as before.
Sustainable development strategy is the only way for people to survive demand such constructions that consumes the lowest number of resources, but at the same time ensures quality living conditions for human being. Using natural materials with suitable technologies gives a possibility to ensure not only high level of heat insulation indexes and reduce construction cost, but also, not less important, reduce bad influence to human health that is authentic in the case of applying artificially produced construction materials.
From 70-s of the XX century in developed countries we can observe revival of interest to such technologies. Many things that were done on individual and experimental level nowadays become a standard construction practice which is supported by the government through financial and other institutions. Accumulated experience allows us to confirm that using local natural materials is important part of environmentally reasonable housing.
Ukraine has a great potential using local materials as building resource which is not really used nowadays. Mostly it concerns to thatch of grain crop. Annually its accessible amount is about 5 millions tones. No doubt that certain part of it can be used to provide Ukrainian people with cheap, energy efficient and secure housing.
2. Low-rise estate construction
Low-rise estate construction as one of the promising types of housing is prioritized direction which development is foreseen by the State Housing Programme of Ukraine. It can be applied both in the city and in the village.
Its major advantages compare to multi-storey buildings are:
Low-rise estate construction is the main building type in many developed countries.
For instance, in 2004 in the USA 355 millions of living quarters were built. Out of them 305 millions of living quarters are wooden bungalows. Similar scenarios can be seen in other countries.
Unfortunately, during soviet times only multi-storey building has been developed by using reinforced concrete construction and ceramic bricks. This situation, up to certain extend, also remains nowadays in independent Ukraine. In 2006 at least 6709 square meters of housing out of the 8 626 thousand square meters put in to operation are urban multi-storey buildings made of reinforced concrete.
Major problems that hold back development of low-rise building in Ukraine are:
Therefore, low-rise building development is dependent on resolving complex interconnected problems that requires very detailed state action programme and state support in financial and social spheres.
3. Energy efficiency
Significant (almost 42%) part of housing and communal services is on the balance of energy consumption of Ukraine determines the importance of effective and urgent problem solving of energy-efficiency within housing and communal sphere.
Let us refer to the state document – concept of national strategy in house building:
Therefore, in Ukraine technologies that are used in mass low-rise estate construction should meet the following requirements:
4. Widespread materials and technologies in modern few floors construction
4.1 Wooden houses
4.2 Frame constructions
4.3 Brick walls
4.4 Light-weight concrete (foam concrete, lightweight aggregate concrete, polystyrene concrete)
4.5 High-density concrete
4.6 Heat insulators
Heat insulating materials by its type of major raw material are divided into organic and non-organic.
Organic heat insulating materials depending on their origin type can be conditionally divided in to two types:
4.6.1 Wood-fibrous heat insulating plates
4.6.2 Peat plates
4.6.3 Building portage
4.6.4 Heat – insulating plastic materials
Thermoplastic (styrene, polyvinylchloride, polyurethane) and thermosetting (urea-formaldehyde) pitches, gas and foam generating substances, fillers, plasticizer, dye stuff etc are raw materials for heat insulating plastic manufacturing.
Depending on the structure of heat insulation plastic can be divided into two groups: foam plastic and pore plastic.
Foam plastic is sponginess plastic with low solidity and availability of no connected between themselves cavities or cells fill in with gas or air.
Poroplast is pore plastic which structure is characterized by connected cavities.
To non-organic heat insulating materials belong mineral wool, glass fibre, perlite and vemiculite, asbestos-containing heat insulating materials, sponginess concrete, etc.
4.6.5 Mineral and glass wool
4.6.6 Foam glass
4.6.7 Aluminium foil (alu foil)
5. Conclusion with regard to the group of widespread materials
In our opinion from the above list, the most suitable for mass low-rise building in Ukraine are spongy concrete and silicates (foam concrete, gas concrete and gas silicates). This conclusion is based on the following joint characteristics:
Other materials and technologies do not have listed joint characteristics; however some variables can be valuable enough. Otherwise increase of some parameters brings to the reduction of others. For instance revetment with plastic sterol improves heat insulating characteristics, but at the same time causes price increase and also lowers gas penetrability. Some heat insulations can be cheap but not healthy. Even though wooden house have a natural look they are very expensive and have inside heat holding properties. Therefore mentioned materials can be used somewhere close to production site to eliminate logistic costs or for building elite housing or to be used for office and other types of similar constructions (shops).
6. Usage of local material
6.2 Reed-fiber mat
6.4 Clay–stover filling material for framework walls
6.5 Straw mat
6.6 Straw bales
As we can see from practical experience and theoretical analysis technology is absolutely reasonable to be used. However, like many other building technologies it has its niche that limits its application. Therefore, by no means we can discuss its universality. For instance, statements about extremely low construction price we can only hear from enthusiasts, and they do not respond the reality. In modern house made by to taking into account modern demand level to comfort and lifestyle, the cost of walls is about 15% from the total construction cost. So for instance if we presume that straw bales are twice as cheap as other materials used in construction we can talk about savings not more than 7.5 %. But we can state that major advantage of this technology is extremely high heat engineering indexes and also material safety for the environment as well as human health.
In spite of compared walls building speed it is difficult to link it to the potentially industrial construction methods. During construction time there are many moments that require taking individual decisions and overall technology is characterized as the one that requires high attentiveness to details.
Straw bales building technology is mostly suitable in those cases when you build the house on your own without inviting contract workers. Only from such houses we can receive expected results with regard to construction cost and exploitation and also comfort level which consists only of objective indexes and feelings that receive those who are going to live in such houses.
Using technology is mostly reasonable with the following conditions:
7. Conclusion concerning comparative analysis within the group of local materials
Applying reed-fiber mat to the walls as it is or combining it (external heat-insulating) which is more reasonable when it is possible to get enough of it close to the construction site and also have a possibility to store raw material by using environmentally friendly methods. Appropriateness can be influenced only by the mechanical logistic process. Certain interest is attracted by using rush from biological system of water cleaning (artificial bogs), but only under the conditions of excluding accumulating of heavy metals and other harmful substances inside the materials which can be in sewage.
In other cases to build using straw bales is more reasonable considering more mechanical level of straw preparation and moving bales, extremely high level of heat engineering indexes and also possibility to reduce consumption of timber. Under energy cost increase conditions the last factor becomes very crucial. When it is impossible to use straw bales, monolithic wall made of clay straw is an alternative method. This method has high level of time and work consumption during construction and also it is compulsory to apply wooden frame which should be duplex. Building from pugging stuff and clay rolls can be used as an extreme case because of the lack of the above mentioned materials and wood deficit to make a frame. It is mostly reasonable under the conditions of atmospheric precipitation and big number of sunny days.
8. Conclusion with regard to comparative analysis between groups of common and local materials
Analysis within the group of widespread materials shows that for mass low-rise building spongy concrete and silicate have the best joint characteristics.
Comparison of these materials with local shows us the following picture.
By heat protective characteristics straw bales exceed spongy concrete as twice as much. However, spongy concrete has better heat accumulating indexes.
It is difficult to compare the building speed by using straw bales and spongy concrete, because it depends upon many factors. However, majority of analyzed sources indicate that both technologies are speedy building method which does not require endurance of drying, absorbing etc. The advantage of spongy concrete is lack of plastering, besides it is important to cover it with moisture-resistant liquid.
While comparing these materials work consumption is almost on the same level. Building by using spongy concrete requires less use of timber compare to straw bale construction, but when doing the main wall with straw bales these indexes comes down to the same level.
Spongy concrete has worse influence indexes to the environment due to atmosphere pollution and high level of energy consumption during production. Cement production from spongy concrete also can have negative influence to the people health. Straw is a waste and during its manufacturing there is no additional pollution or energy consumption.
Spongy concrete has a high level of fire safety. However plastered straw bales also allow reaching high level of fire safety.
Spongy concrete price is higher compare to straw bales (the same volume). To the price of spongy concrete we should also add the price of viscous (cement or glue) that helps to pile bricks and the price of moisture-resistant covering. However, straw bales plastering can be very costly.
Gas penetrability of both materials is very high, however better indexes has a wall made of straw bales plastered with clay.
Taking into the consideration all the above information it can be concluded that only using ecological indexes straw bales are better material to use compare to spongy concrete. However in the real life, nowadays other factors can be not less reasonable (industrialization and availability of production base). As it was mentioned above straw bale suit better when you decide to build yourself and not inviting contract workers and perhaps this type of building has its niche these days.
Low-rise construction by using local materials such as straw and rush is one of the powerful ways to resolve sharp housing problems in Ukraine. Using these technologies compare to conventional construction methods has got the following advantages:
By now, from many points of view, both in national as well as in alternative building big experience of using straw and rush is accumulated and that allows us to confirm that cheap, long-lasting and ecologically secure houses can be built. Compare to ordinary building technologies (bricks and concrete) qualitative analysis of energy balance and environmental risks shows the effectiveness of using mentioned local materials. Particular attention deserves using pressed straw bales building technology. This method allows us to receive the best heat protective properties under the conditions of low energy consumption that can be 30 times less compare to modern houses using artificial heat-insulating materials (mineral wool or polystirol). Up to date thousands of houses have been built in many parts of the world. It is a pity that Ukraine having lack of energy resources and housing and owns such a huge resource of straw, remains aside to this process. Every year out of 5 million tones of straw, which is available in Ukraine theoretically 42 millions square meters of housing or 699300 buildings with an area of 60 square meters can be built and they consume heating 3-4 times less energy compare to the housing premises that are used now.
Construction with local material also has its disadvantages and restrictions as any other building technology. However, major restrictions that limit these technologies have subjective attitude compare to objective factors like:
Analysis of the situation shows that, in order to introduce building from local materials the following steps are necessary:
It is important to emphasize that there are no universal construction technologies and expediency is first of all conformity to certain location, conditions and other factors. Both materials and techniques can be used or not used under different circumstances. Also using one type of materials does not exclude using the other that means that various types of material could be combined or used in different parts of the building. To establish such suitability can be very complicated task which we think should be resolved based upon synthesis of ecological and construction sciences.