With wood and turf. A hearth can be found in virtually all excavated houses. Often this is a round spot with a lot of charcoal and orange burned clay. The hearths sometimes were constructed on small platforms. A normal fire in a hearth can reach temperatures over 900° C. Thick wattle and daub walls (with straw worked through them for insulation) kept the warmth inside very well. Houses with floors consisting of crosswise layers of reeds have been found. Parts of wooden floors have been found too. From later times we know that walls were sometimes covered with fabric (a kind of tapestries). A large skin or blanket in the door opening helps too.