What is a straw bale?A bundle is called a block of straw, normally pressed, which largely replaced the heap as a method of preserving food for animals. It is also known by the name of bale. At the beginning of this technology, and until relatively recently, prismatic-shaped bales were used, currently displaced by cylindrical ones, more suitable for handling by machines and which are usually called bales. It is common for bales to be used not only to preserve straw, but especially to preserve other types of forage crops that are cut and processed before they are dry, as a way of obtaining maximum nutritional yield. standard dimensions 1,000 mm x 450 mm and approximately 18 kg are used for the construction of houses from 50 m² to 500 m². This is used because it is an ecological and self-sustaining material.
Construction Applications:The straw has big qualities as a sustainable building material:
It is a one hundred percent natural product that does not require prior treatment of any kind. The only thing to ensure is that the bales are of good quality.
It is a local material with the consequent energy savings and CO2 emissions that it entails.
At the end of its useful life it does not become waste but is completely biodegradable.
Straw bales are technically very efficient as they are great thermal and acoustic insulators that amply comply with current regulations.
Straw is a material that breathes, not that the interior air is always being renewed.
It is an easy-to-apply construction material that allows the wall to be raised in a very short time. The simplicity of the art of building with straw makes self-construction one of the most widespread options. The procedure is based on stacking the bundles on top of each other as if they were giant bricks without the need to put any type of adhesive or support between them.
It is an economical material that makes the final price of the house very low.
main problems of straw building:
Water. It is important to protect the straw from water during the construction process until the work is finished. It is advisable to build the building on a raised base that protects it from currents and soil moisture.
The fire. Loose straw burns very easily, but the density of compacted straw bales usually means that there is little air inside them and combustion is retarded.
To solve the problems caused by water and fire, it is convenient to make a good coating. This means that the external appearance of a wall raised with straw bales does not have to differ from that of a conventional house. The coverings are usually made of mud or lime, giving it a more creative and organic touch with walls with a spongy finish and avoiding straight lines with walls more than half a meter thick.
main materials:
Straw is made up of the dead stalks of grain crops. The most used for construction are wheat, barley, rye or oats.
The bales must be dry and, if necessary, keep them under cover if rain is expected. They must also be well compressed.
Basic principles to follow for building:
For load-bearing walls that support the weight of the roof, the bales will be placed one on top of the other and hazelnut stakes can be nailed inside to give more rigidity and join some bales to others.
Using straw bales as fill means that the wooden frames for the walls and roof must first be built to provide structural support. Once the structure is finished, the free spaces of the walls are filled with straw bales.
Try to make the walls take up the length of several whole bullets with no areas smaller than half a bullet.
Place doors and windows at least one bale away from load corners.
It is better to avoid the use of metal fasteners on the walls as they favor the condensation of warm and humid air inside the house. It is preferable to make the straps based on rope.
Use a breathable whitewash or lime-based paint for finishes to protect the building from the elements. Lime plaster is made up of one part quicklime and three parts wet sand and can be colored with powdered pigments or paints.
If the insulating base of the ground is not enough, it is advisable to protect the lower part of the building from the splashes of rain that falls on the base and can cause humidity problems.
We leave you two links to the book “The house of straw bales” for reference.http://es.scribd.com/doc/28822761/La-Casa-De-fardos-de-paja-libro-completohttp:/ /www.ecoaldea.com/Biohabitat/casa_paja.htm sources:
