l. Clean cork plates made of cork grains, elastic, thick 10 — 50 mm, surface dimensions 500 X 1000 mm, c. obj. about 0,184, thermal conductivity 0,036. They are mainly used as soundproofing. 2. Asphalt cork slabs made of dried ground cork, mixed with an odorless asphalt binder, pressed under pressure, thick 30-120 mm, surface dimensions 500 X 1000 mm, c. obj. about 0,2, thermal conductivity of approx 0,045, compressive strength 12 – 15 kg/cm2. These boards are resistant to moisture. Thick plates 30 — 40 mm is used to insulate roofs, while thicker ones - in cooling construction. 3. Strongly pressed clean cork slabs, 2 - 50 mm thick, c. obj. 0,25—0,3, thermal conductivity of 0.04-0.05, compressive strength 35-40 kg / cm2. They are used for gaskets and as foundation insulation against vibrations caused by the movement of machines, industrial equipment, cranes etc.. 4. Expanded clean cork boards (mostly imported). They are made of cork grain, subjected to expansion, i.e.. steaming with steam at a temperature of about 350 ° C, and then dried. They are boards 30-120 mm thick, surface dimensions 500 — 1000 mm, c. obj. about 270 kg/m3, thermal conductivity 0,036. These plates are very flexible. They are used as thermal and acoustic insulation. In addition to the above-mentioned, also expanded clean cork boards, o c. obj. 164 kg/m3, in thicknesses of 10-60 mm.