210
Floor and Ceiling Layout
Opening context:
Efficient Structure, Ceiling Height Variety, Roof Layout
Conflict
Again, the basic problem is to maintain the integrity of the social spaces in the plan.
Resolution
Draw a vault plan, for every floor. Use two-way vaults most often; and one-way barrel vaults for any spaces which are more than twice as long as they are wide. Draw sections through the building as you plan the vaults, and bear the following facts in mind:
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Generally speaking, the vaults should correspond to rooms.
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There will have to be a support under the sides of each vault: this will usually be the top of a wall. Under exceptional circumstances, it can be a beam or arch.
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A vault may span as little as 5 feet and as much as 30 feet. However, it must have a rise equal to at least 13 percent of its shorter span.
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If the edge of one vault is more than a couple of feet (in plan) from the edge of the vault below it — then the lower vault will have to contain an arch to support the load from the upper vault.
Closing context:
Perimeter Beams, Floor-Ceiling Vaults, Final Column Distribution, Floor Surface, Columns at the Corners