3 BUILDING MATERIALS NATURAL MATERIALS (1) Two groups of building materials Building materials can be generally categorized into two groups, natural and synthetic or man-made. are those that are or by industry, such as wood. 1 Natural building materials unprocessed minimally processed Fabric Two well-known types of tent are the conical teepee and the circular yurt . The tent has been revived as a construction technique, with the development of . Modern buildings can include flexible materials such as membranes supported by a system of steel , a rigid or internal air pressure. Tents used to be home for nomadic groups all over the world. 1 tensile architecture 2 fabric cables framework Mud and clay The amount of each of the two materials used usually depends on the quality of the soil used. The other main ingredients can include sand and/or . Soil and especially clay is good at keeping temperatures at a constant level. Homes built with earth tend to . Clay retains or cold, releasing it over a period of time, like stone. Walls change temperature slowly, so artificially raising or lowering the temperature can take longer than in a wooden house, but the heat and the coolness will stay longer. gravel be naturally cool in the summer and warm in cold weather heat WARM UP Which nomadic people lived in tepees? DO Do you think building materials are different in different geographical areas? Give examples. 1 MORE Tepee: conical tent used by Native Americans. Yurt: circular tent used in the steppes of Central Asia. 1 MORE Tensile architecture is a structural system that predominantly uses tension instead of compression. 2 Rock Rock structures have always existed. It is the building material and is usually readily available. There are many types of rock, all with different properties making them better or worse for different uses. Rock is a very dense material so while it can offer , its main disadvantage as a building material is its and . In addition, stone is without using large amounts of heating resources. walls, that is to say, walls with no joining material (or ) between the individual stones, have been built for an incredibly long time. Different forms of mortar can of course be used to hold the stones together, and cement is the most common now. longest-lasting a lot of protection weight hardness hard to keep warm Dry-stone mortar Rural mud house in India Thatch This is . and together are and are available nearly everywhere. In Europe, roofs on homes were once common but the material was gradually abandoned as industrialization and transport increased the availability of other materials. one of the oldest building materials known Straw reeds good insulators thatched Interior of a rock house in Matera