|
Throughout
history the construction of buildings has been done
mainly with materials that can
be found locally. In Italy and Greece they relied on
marble as large quarries were near-by. In Northern Europe
timber was abundant so timber-frame structures out-numbered
stone. The farther away the material
had to come from, the more money it would cost.
Let’s
start at the bottom of a building and see what materials
its’ made of!
The
foundation of a building has to hold
everything that is built above. Until recently many
people built their houses and businesses right on the
bare earth , packing it down hard.
Wood could be laid down over the ground.
This method didn’t provide much insulation from any
cold weather. If stone was available
that could be used as a flat sturdy floor but stone
doesn’t stay warm in the winter. Tile
and earthen floors have been preferred in hot climates
as they stay cooler than the air temperature. Today
we often use a mixture of concrete
and steel with an insulated covering
as our preferred foundations . This
mixture provides strength and protection from the elements.
The
structure that rises up from the foundation
is the skeleton of the building. The most common building
method for thousands of years has been Post-and-Lintel
Construction. It was first seen in ancient
Egypt . It is said to come from an early building technique
where firmly bound sheaves of swamp reeds were used
to support roofs in adobe structures.
Builders eventually switched the reeds to stone
columns and could enclose very large spaces.
Look up post-and-lintel in the glossary of terms.
The posts and lintels were made out of wood
. For very large structures such as cathedrals
and churches stone was used to create
large columns or piers incorporating arches
and vaults . In modern construction we still
use wood framing for smaller structures but fortified
with concrete and metal. Have you
ever seen a skyscraper or very large building being
built? They use concrete and steel
as the skeleton and it allows them to build
up tens of stories high.
The
outer walls of a building or house
are called the load-bearing walls
because they hold the weight of the roof and stabilize
the internal structure. There are two types of load-bearing
walls, the frame-construction walls
and the mass-construction walls. Frame-construction
walls have a skeleton of wood
or metal that are then filled in or
covered by another material. A good example of this
is timber-frame construction found on many English-style
houses. In between the timber frame posts thin strips
of wood were affixed called wattle .
Over the wattle a mud or clay mixture was applied called
daub . When outer walls are completely
solid and made of brick or stone
they are called mass-construction
. In warmer climates mud brick or adobe
is preferred for the walls because their thickness
doesn’t allow the heat to penetrate, keeping the inside
cool.
Look
at the following picture of the outside of the Molly
Brown House Museum . Is it a frame-construction
or mass-construction wall?
Is it made of brick or stone
?
We’ve
already looked at the a roof as an
outline shape but what is that roof
made of? What you see from the outside is the final
layer on the roof and changes with building styles and
locations. Tiles are the most common way to finish a
pitched roof and can be made of clay
, slate , sandstone
, asphalt or wood
. Metal roofs can also be found and are made
of copper , lead ,
tin and even gold
like the dome of Denver ’s capital building. A third
type of roof is a thatched roof and is made with bundled
layers of straw or other plant material.
Look
at the following pictures and decide what these roofs
are made of:
  
Let’s look at styles!
|
