A wall is a structure that defines an area, carries a load, provides shelter, security and also divides spaces. Walls can be constructed in various ways like cavity and solid walls using a variety of materials like stones, bricks, blocks or any other like material.
Walls have numerous functions and these include;
· Support upper floors and roofs together with their super imposed loads.
· Walls should resist damp penetration since this is one of the serious defects.
· Provide adequate thermal insulation by preventing excessive loss of heat from within building and preventing large heat gains from outside.
· Provide sufficient sound insulation.
· Walls should offer adequate resistance to fire.
· To look attractive and satisfactorily accommodate windows and doors.
There are 2 forms or categories in which walls are constructed i.e.
Solid wall. This consists of a single leaf of brickwork with a minimum thickness of 225mm for external walls and 150mm for internal. This type of wall is economical in construction but it’s not always damp-proof particularly in locations exposed to driving rains since moisture may penetrate the walls through brick joints or through minute cracks which for between the bricks as the mortar dries out.
Cavity wall. This is constructed of 2 leaves or skins with space or cavity between them and it’s the most common form of external wall used in areas of cold temperature like in Europe. Since the main function of the wall below the ground level (commonly known as plinth wall) is to transmit the load safely to foundation, then the cavity or space between the 2 leaves should be filled with a weak mix of concrete to create a “solid wall” in the ground. The head of cavity wall is usually built solid to spread the roof load over both leaves.
Advantages
· The wall is able to withstand a driving rain in all situations from penetrating to the inner wall surface.
· The wall gives good thermal insulation keeping the building warm in winter and cool in the summer.
· There is no need for external rendering like plastering.
· The wall enables the use of cheaper and alternative materials of the inner constructions.
· Has a higher sound insulation value than solid walls.
Disadvantages
· Requires a high standard of design and workmanship and good supervision to produce a soundly constructed wall.
· The wall needs vertical damp-proof courses to all openings, hence; expensive
Types of walls
There are numerous types of walls that can used during construction and all this is dependent on the purpose and/or nature of building and environment in which the wall is to be erected. They include;
External walls. These are walls that enclose a building and therefore are exposed to the outside of the building. These walls can be constructed as cavity walls or as solid walls.
Masonry Wall. Masonry means building a wall pilled with single units of bricks with the joint filled with mortar. It is one of the most common forms of the wall. While erecting it, the number of bricks is arranged to give it the shape of a wall.
There are two types of brick masonry walls. One is a 200mm and widely used for exterior wall, and the other one is a 100mm widely used for interior wall &/or internal partitions. As a masonry wall doesn’t contain any rod or steel between the structures, the longest you can go for a single section is 4 meters.
Partition walls. These are internal walls that divide the interior of a building into areas of accommodation and circulation; they are classified into 2 categories namely
a) Load bearing partitions. These are internal walls designed and constructed to receive super imposed loadings and transmit these loads to a foundation. These partitions are generally constructed of bricks or blocks bonded to the external walls. Fixings be built directly into the walls or the walls may be drilled and plugged to receive nails or screws.
b) Non-load bearing partitions. These internal walls are designed and constructed to carry their own weight and any fittings or fixings that may be attached to them but they must not under any circumstances be used to carry or be used in the transmission of structural loadings. For example; Timber stud partitions and preformed partitions are best suited for this type of internal walls because they are higher than brick or brick partitions; Curtain walls also merely keep the weather out and the occupants in and its designed to resist air and water infiltration, sway induced wind and seismic forces acting on the building.
Parapet walls. These are walls that slightly exceed a concrete roof slab to give fencing around the deck or balcony. These walls can be either solid or cavity since they are exposed to the effects of weather, they must be provided adequate barriers to moisture by means of damp-proof courses.
In low parapet walls a damp-proof course should be inserted under the coping and the roof covering extended up the inside face of the wall and tucked in under the damp-proof.
With taller parapets 2 damp-proof courses are required, one under the coping and the other at or near the roof level and lapped with the roof covering.
Boundary walls. These are walls that are subjected to severe conditions and therefore need protection against water since it can lead to frost damage; mortar failure and efflorescence. The wall should incorporate adequate damp-proof courses and over hanging throated copings to be able to withstand the severe weather conditions.
Retaining walls. These are walls that are constructed around soil so as to sufficiency counteract the tensile stress caused by the lateral load of soil and water. These walls can be constructed of bricks, blocks, stones or concrete and be reinforced by means of attached piers (a raised structure typically supported by well-spaced pillars) or by means of attached buttress wall (an arch structure built against or projecting from a wall which serves to support/reinforce the wall).
Shear walls. These are usually built to resist lateral forces caused due to earth pressure, hydrostatic pressure, wind, earthquakes etc. In such situations, a shear wall helps to considerably reduce the lateral sway. They are thin walls and light in weight.
Precast Concrete Wall. Precast basically means having a form prior. The wall is designed to have a tough exterior that can withstand inclement weather.
To get the correct shape or form, several sizes of molds are required for various sizes of concrete blocks, and the procedure is carried out entirely on the inside. Different sorts of rocks are utilized depending on the desired strength and texture.
Based on some history data, precast walls date back to the ancient Roman empire. The builders of the day put the material into a mold and formed a slab for wall construction.
Present day methodology has made it possible to combine the pieces in the machine and adjust the size as needed, so you can have different walls (even huge ones) using different molds easily, built sometimes with cranes even.
Other types are; Core Wall, Stone Wall/Rubble Stone Masonry Wall, Reinforced Brick Wall, Glass Wall, Wood Wall, Steel Sheet Wall etc.