The
following model shows how these structural members can be combined
together to |
create a
custom home with an open hip roof. |
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 |
 |
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Fig. 215 - Custom home |
with open hip roof |
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(scale visualization model) |
click image to enlarge |
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Most
public, commercial, and industrial buildings can classified into three
main categories- |
wall
bearing, skeletal, and long span structures. |
. |
Wall
bearing construction |
. |
Wall
bearing construction is one of the oldest and most common building methods
used. |
Exterior
and interior masonry walls support structural members like beams and
joists that |
carry
the building's floors and roof. Its use is limited to low profile
buildings up to several |
stories
high. |
. |
 |
|
 |
Fig. 216 - Wall bearing |
construction |
|
detail of truss joist roof ► |
(scale visualization model) |
click image to enlarge |
|
. |
Historically, wall bearing construction was used to build some of the
largest structures then |
known.
As mentioned previously, the Romans overcame the interior space
limitations of |
the
classical post and lintel system by using arched, vaulted, or domed roof
designs. These |
massive
superstructures exerted a considerable outward thrusting force on the
perimeter |
walls
supporting them. Consequently, bearing walls were very thick to keep
from being |
tipped
over from the roof load. The thickness of the walls was not
necessary to resist the |
compressive stresses exerted by the roof load since, as stated before,
masonry, such as |
stone,
brick, or concrete has very high compressive strength. However
excessive thrusting |
forces
bearing on top of the wall can cause the wall to become unstable over
time. This is |
due to
the fact that masonry has a relatively high modulus of elasticity.
So the eccentricity, |
or
unbalance, of the thrusting load of the roof will cause the outside of the
wall to shrink in |
compression and the inside of the wall to expand in tension. In reaction
the wall begins to |
. |
Back
to Knowhere |
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Page 128
- Building stability - Wall bearing construction |
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