House raising
House raising (house lifting, house jacking, barn jacking, building jacking) is the process of separating a building from its foundation and temporarily raising it with hydraulic screw jacks. The process is the first step in structure relocation in which the building is moved to a different location. House raising may also be a part of a renovation to build a foundation under an existing house or make a house larger by building a new floor level creating a two story house. Often employed in areas that are prone to flooding and storm damage, this process can be achieved through the use of either timber piles or helical piles. Once a house is raised and supported on cribbing, a new foundation can be constructed beneath it. After Hurricane Katrina and Hurricane Sandy large numbers of houses in parts of Louisiana, New York and New Jersey were raised to avoid future flooding.
Rural Khmer house
Typology of Khmer house
The building consists of a supporting framework, which stands on individual foundations. There are no bracing or shear walls to strengthen the structure. The roof is built before wall cladding is applied.
The load-bearing piles of the building stand on single foundations. To comply with the specific conditions of the generally loamy soils, single foundations are laid in the following manner:
At the bottom of a 1 metre deep excavation several wooden poles of 1.5 – 2.00 metres length are rammed into the ground and then covered with a layer of compacted stone, followed by a hewn stone or prefabricated concrete slab, which provides the base for the pile. The excavation is then filled with soil. In a modern version the single foundations are linked with concrete slabs and prefabricated pillars extending to the upper floor are used.
For each pile, a single round hardwood tree trunk, such as .(…) is used. Extending from the foundation to the roof, and in the centre as far as the roof ridge, the piles, together with the horizontal joists, form the bearing structure of the house.