After hemp, wool sheep or duck feather, it is the turn of the grass to join the young family of natural insulators with Gramitherm. Invented by a Swiss engineer, this insulation consists mainly of fibers made from dried herbs. With one hectare of meadow, it would be possible to produce 200 cubic meters of insulation, that is to say what to equip seven houses of average size. To make your own opinion on this new material that claims to be ecological, this week DIYDubranche invites you to discover the Gramitherm.
The properties of Gramitherm
Gramitherm is a material intended to isolate cold, heat, but also noise. It is composed of fibers extracted from meadow grass, to which a binder (polyethylene or starch) and mineral salts are added. Gramitherm has a thermal conductivity coefficient of 0.034 for panels 15 centimeters thick. In other words an excellent performance that offers a quality of insulation superior to those of wools of rocks and glass wool. In addition, contrary to what one might think, Gramitherm panels are fireproof (class E) and resistant to fungi and mold. As a result, this insulation is approved and complies with European standards. Gramitherm also absorbs water vapor and regulates the humidity of the building.
Gramitherm in practice
Gramitherm is packaged in lightweight panels. It is a non-allergenic insulator that gives off a slight hay odor. It is handled without danger. In addition, it is easy to cut, cutter or knife and requires no specific equipment. Its installation is thus accessible to all, even to the handymen of Sunday. On the other hand, Gramitherm is suitable for interior insulation as well as for the external insulation of buildings. Thus, it is used mainly for the insulation of rafters and roofing, the lining of interior partitions and external walls, but also for the insulation of floors and ceilings. Finally, note that Gramitherm is an insulator of choice for wood frame houses.
The advantages and disadvantages of Gramitherm
The major attraction of Gramitherm seems to be its low ecological impact. Indeed, its production requires little energy and produces virtually no greenhouse gas. It also helps to reduce CO2 by absorbing it during the growth of the grass. Note, however, that Gramitherm contains polyethylene, a petroleum derivative however easily recoverable. Another advantage of Gramitherm, its price is in the lower range of ecological insulation (count about 12 euros excluding tax per square meter). However, we regret the lack of obvious decline of this young product that does not allow to know its durability and performance over the long term. Finally, it is unfortunate that Gramitherm is very little used in the sales channels and that it is difficult to obtain in particular in France.
To conclude this survey, HandymanDuDimanche hopes that this green insulation will develop and will be successful otherwise than on the stands of exhibitions dedicated to green buildings. And to discover other ecological insulators, go to this week's selection of products.