Think of a straw-bale house and you might imagine a tumbledown shack that leaks, creaks, and slumps.
But step into BaleHaus, a startlingly contemporary looking prototype home that has been built on the Bath campus, and there's nary a wisp of straw to be seen.
The straw bales are all packed tightly inside a series of prefabricated rectangular wooden wall frames, which are then lime-rendered, dried and finally slotted together like giant Lego pieces, called ModCell panels.
The benefits of straw, points out Professor Peter Walker, director of the University of Bath's BRE Centre for Innovative Construction Materials, are that “it's cheap, widely available and a good insulator. It's been used in building houses for hundreds of years”.
Unlike conventional building materils, straw offers a welcome solution to housing's greenhouse gas emissions.
The results now being published. The researchers spent the last 18 months testing the BaleHaus against an exhaustive list of risk factors that could rot it, burn it or blow it down, so far seem to be reassuring.
The ModCell unit was strapped to a fiery furnace with temperatures of over 1000 degrees C but it did not end up as ashes.
It took an hour-and-a-half of being in direct contact with the flames, says Dr. Katherine Beadle, a research partner, before the lime render began to drop off, “and then the straw did start to burn back, but because it's so compacted it suffered more charring than actual disintegration.”
Hydraulic jacks were placed against the walls to replicate wind forces pushing against the bales — the ModCell panels moved a few millimetres, but stayed within the tolerances allowed for by the computer modelling carried out prior to its construction.
“It means the house is stiffer than it needs to be, so we now have the option of taking away some of that stiffness — ie, reduce its internal timber — and that could reduce the cost,” says Dr. Walker.
In the airtightness test that was carried out, BaleHaus came in way under the building regulations threshold.
In the flood test the researchers are going to stand a panel in a metre of water, gauge how long it takes to dry and assess whether industrial driers cause damage to the straw. — © Guardian Newspapers Limited, 2010
Source:The Hindu 15 July 2010
But step into BaleHaus, a startlingly contemporary looking prototype home that has been built on the Bath campus, and there's nary a wisp of straw to be seen.
The straw bales are all packed tightly inside a series of prefabricated rectangular wooden wall frames, which are then lime-rendered, dried and finally slotted together like giant Lego pieces, called ModCell panels.
The benefits of straw, points out Professor Peter Walker, director of the University of Bath's BRE Centre for Innovative Construction Materials, are that “it's cheap, widely available and a good insulator. It's been used in building houses for hundreds of years”.
Unlike conventional building materils, straw offers a welcome solution to housing's greenhouse gas emissions.
The results now being published. The researchers spent the last 18 months testing the BaleHaus against an exhaustive list of risk factors that could rot it, burn it or blow it down, so far seem to be reassuring.
The ModCell unit was strapped to a fiery furnace with temperatures of over 1000 degrees C but it did not end up as ashes.
It took an hour-and-a-half of being in direct contact with the flames, says Dr. Katherine Beadle, a research partner, before the lime render began to drop off, “and then the straw did start to burn back, but because it's so compacted it suffered more charring than actual disintegration.”
Hydraulic jacks were placed against the walls to replicate wind forces pushing against the bales — the ModCell panels moved a few millimetres, but stayed within the tolerances allowed for by the computer modelling carried out prior to its construction.
“It means the house is stiffer than it needs to be, so we now have the option of taking away some of that stiffness — ie, reduce its internal timber — and that could reduce the cost,” says Dr. Walker.
In the airtightness test that was carried out, BaleHaus came in way under the building regulations threshold.
In the flood test the researchers are going to stand a panel in a metre of water, gauge how long it takes to dry and assess whether industrial driers cause damage to the straw. — © Guardian Newspapers Limited, 2010
Source:The Hindu 15 July 2010
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