Straw is a by-product of the agricultural industry; it is often used as an insulation and roofing material in construction. Like wood, straw is also affected by biotic and abiotic factors causing a variety of damages. Since it lately more often came to degradation of straw roofs, we examined the possibilities of straw protection. Nowadays, copper-ethanolamine preparation is used to protect wood against biological agents, therefore we assumed that this could also be the adequate protection of straw, which is also a lignocellulosic material. The straw was submerged into Silvanolin at different concentrations (0.25 % and 0.5 %) and for 2 different time periods (5 min and 60 min). We studied the optimal impregnation time to reach the optimal absorption of copper substances. The maximum absorption of copper in the straw was determined on samples that have been treated in a solution of a higher concentration, and also for a longer time. On the other hand it has been shown that the copper-ethanolamine preparations form chemical bonds with straw. Leaching of copper was the highest on the first day, but then it decreased. We came to the conclusion that the protection of straw with copper preparations affects the growth of mycelial fungi. The best protection was achieved with 0.5 % concentration of Silvanolin, where a barrier between the fungus and the straw was created.