drevo 1 [vynechat] fire retardants flammability 1 [vynechat] horľavosť 1 [vynechat] laboratory diagnostics 1 [vynechat] laboratórna diagnostika 1 [vynechat] smreky 1 [vynechat] spomalovače horenia 1 [vynechat] spruce 1 [vynechat] tepelné vlastnosti materiálov 1 [vynechat] thermal properties 1 [vynechat] vlastnosti dreva 1 [vynechat] wood 1 [vynechat] wood properties 1 [vynechat] wood structure 1 [vynechat] štruktúra dreva 1 [vynechat]