19-03-2014, 11:59 AM
WATERPROOFING SYSTEMS FOR BASEMENT
BASEMENT
A basement is one or more floors of a building that are either completely or partially below the ground floor. Basements are typically used as a utility space for a building where such items as the furnace, water heater, breaker panel or fuse box, car park, and air-conditioning system are located; so also are amenities such as the electrical distribution system, and cable television distribution point.
Daylight basements
A daylight basement or a "walk-out basement" is contained in building situated on a slope, so that part of the level is above ground, with a doorway to the outside. The part of the floor covered by the ground can be considered the true basement area.
Look-out basement
In a "look-out" basement, the basement walls extend sufficiently above ground level that some of the basement windows are above ground level.
Where the site slopes gently and is insufficient for a walk-out basement, a look-out basement tends to result.
The advantage is that the basement windows are all above grade.
The disadvantage is that the main floor entry is above grade as well, necessitating stairs to get up to the main floor.
Construction of basements
For each case of basement construction, the method of soil support, sub-soil condition, structure of the basement as well as the layout requirement of the entire building must be taken into consideration before designing the method of works.
Method of constructing ordinary basement
One of the most effective methods to construct ordinary basement is by the use of diaphragm wall or sheet pile wall (cut-off) which serves as a retaining structure during excavation and as the sides of the basement walls. When the central soil is removed during excavation, the cutoff wall should be properly supported for works.
Use of lattice beams
A series of lattice beams or steel trusses are installed so that they span between the top of opposite diaphragm walls enabling them to act as propped cantilevers. The trusses can be removed after the internal floors have been constructed and receiving all the lateral forces from soil.
Block, Brick and Stone Walls
basement walls made of concrete blocks, bricks and stone are constructed in some areas of the country. Concrete block walls are easy to build and cost-effective. Brick was frequently used in areas where clay soil for their production was abundant and stone foundations were once favoured as the least expensive basement wall material.