Straw as thermal insulation
Straw is the side-product of agriculture that is used in our place very little and we often may see it is left in the field.
However, the material has excellent thermal insulation properties.
Even our grandparents knew the extraordinary properties of straw, when they stored straw or hay in the attic (the loft) insulating thus the house ceiling. From the point of view of thermal insulation it is an optimum when one m3 of straw weights about 90kg.
Straw packs may be used as an additional insulation of already built house, as the filler of walls when constructing the house with a wooden structure and even also as the carrying wall of a straw house.
Such a wall may be at the level of low-energy standard (for comparison: 50cm wide wall made of straw packs has approximately the same thermal resistance as 35cm mineral wool insulation).
Fire resistance
When hearing the term "straw house", every man would think of the risk of fire. It is true straw burns very well, but only in the case it is in bulk.
As long as the straw is compressed in a pack, where there is a lack of oxygen, it just would smoulder. As long as the packs in the wall are plastered from both sides, such a structure can resist fire for more than 100 minutes according to the recent fire tests.
That means the wall without the plaster application made of straw packs would meet the requirements of fire resistance without problems.
There is the risk of fire during the construction, when the individual stalks stick out from the uncompleted wall and straw is scattered all around. It shall be very important to observe safety regulations at that time.
House made of natural materials
The house made of straw with internal clay plasters provides us with a healthy dwelling made of natural materials without straining environment. It has low demands on heating and it is for lower price than the house made of conventional materials.
When observing the good technological procedures, the life of a straw house shall be comparable with common structures.
The oldest known houses made of straw packs are in Nebraska and they are more than 100 years old.
Sheep wool is the product of nature with extraordinary properties. It is healthy and valuable material with excellent thermal insulation ad sound-proof parameters representing the most perfect construction and insulation material of these days.
