Wall

Walls are vertical surfaces constructed in continuance that divide an enclosed spaced. Walls also serves the purpose of a structural element that transfer the load of roof to the foundation. Walls also acts as a partition which does not take any load in a non-load bearing structure. It is a structure defining an exact area and providing safety & shelter. Walls are the only component of a house that gives the building a proper structure and which accommodates doors and windows. It is known that choice of materials for walls is important for structural stability and acoustics in any building construction. But it is less known that the choice of materials needs to be done carefully, striking the right balance between cost, quality, resource requirements, topographic environment and quality during building construction.

There are mainly two types of walls, loading bearing and non-loading bearing wall. The

  1. Load bearing walls

    It carries the weight of a house from the roof and upper floors, all the way to the foundation in a load bearing structure. This type of wall depends on types of buildings and their number of stories that are assessed to a suitable thickness to bear the weight above them. Without this wall, there is a chance for instability in walls’ foundation works. These are of 8” or more thickness. Such walls are made in first class bricks and rich mortar. The most commonly used load bearing wall is masonry walls

  2. Non load bearing walls

    These walls serve the purpose of dividing the space into required rooms in a framed structure. These can be made into thin sections to save the space. Non load bearing walls are only partition having no load of super structure so these can be easily changed whenever required to change the space of the room. These walls are built lighter with 3 inches, 4 inches and 9 inches thick as per the requirement of the site.

Type of materials used for wall construction

In North Paravur the most widely adopted type of wall construction is load bearing walls in which masonry walls are given preference. These walls form basic units for creating rooms that make up a house and are constructed above the plinth normally on strip foundations. Brick walls are constructed using bricks and mortar where the bricks are joined with cement mortar in a special arrangement, usually an English bond. All construction systems of brick walls are such devised that vertical cross joints in any layers are staggered. The bricks thus bonded form a solid mass that does not split when the wall is loaded with live loads and dead loads.

Purpose of wall (in case of a load bearing wall construction) is to carry the load of the super structure and roof. Whereas walls in case of a framed RCC or pre-engineered structure used as a whether barrier and also for ensuring privacy. Walls will divide and control different functions in a particular building. Materials for construction of wall can be selected by considering the above facts.

It is known that choice of materials for partition walls is important for structural stability and acoustics in any building construction. But it is less known that the choice of materials needs to be done carefully, striking the right balance between cost, quality, resource requirements, topographic environment and quality during building construction. In this section let us look at the following 12 types of bricks used in building construction in Kerala.

The materials widely used in masonry walls in North Paravur are,

  1. Solid concrete blocks or cement blocks

    Concrete block walls being the commonly used material are very strong, durable and fire resistant that can handle high impact pressure. They don’t require maintenance too often and don’t emit any harmful or allergic chemicals. Installation of the concrete block walls is not much labor intensive but need careful designing by professionals, which may add to its cost. For concrete blocks, the commonly available thickness is 200mm (8”), 150mm (6”) and 100mm (4”) and these bricks can be used in framed structures as well. But for load bearing structures, 200mm thick block should be used. Concrete blocks should not be left un-plastered as it can result in deterioration with passing years.

  2. Laterite bricks

    Laterite stones were the widely used construction material for wall in the area. It has the capacity to retain coolness inside the walls thereby creating more comfortable interiors in summer. Laterite stones are nowadays not easily available in North Paravur. Laterite stones are mainly of 230mm thickness and are much heavier than the concrete blocks. The structural stability of laterite stones are being questioned nowadays due to the reduction in the length of the bricks as the vertical joints in the walls are getting closer thus resulting on cracks and reduced load bearing capacity of walls. These bricks are susceptible to abrasion when it is subjected to moisture for a very long period.

  3. Interlocking concrete block

    Interlocking bricks are gaining acceptance in construction these days due to its increased block stability and bonding. Cement consumption will be less than the brick work with cement mortar. Cement consumption for one cumecs conventional brick is 65kg (brick of size 200mm x 100mm x75mm). But for interlocking mud bricks it is 18kg to 22kg cement. While using such bricks, the work can be completed in a fast track mode.

  4. Wire cut red bricks

    Red bricks if available locally is the best material one can use for construction of low rise buildings due to the excellent heat retardation properties. Price of red bricks are usually higher, but heat inside the buildings will be lesser as heat conductivity of cement is higher and bricks made using cement will have higher temperature inside the building. The compressive strength of red bricks depends on how it is manufactured but it is comparatively less when compared with concrete bricks. Such bricks are eco-friendly and fire resistant. Popularity of such bricks has been reduced due to less availability of sand and clay.

Some of the disadvantages of masonry walls are its heaviness and it requires a lot of skilled labor. To run electrical, or any other wires or pipes in a brick wall, you have to first chase the wall. Then you can install a conduit – a plastic pipe – in the wall, fill in the gap around the conduit with cement plaster, and then pull your electrical wires through the conduit. This takes time and effort. Masonry walls cannot be constructed to an unlimited height – broadly speaking, most are considered stable only to a height of 10-15 ft (3 – 4m). To construct a masonry wall higher than that, you have to design a special wall that has intermediate structural members to support the wall.

Masonry walls in load bearing structure rely mainly on their weight to keep them in place; each block or brick is only loosely connected to the next via a thin layer of mortar. This is why they do not perform well in earthquakes, when entire buildings are shaken horizontally. Many collapses during earthquakes occur in buildings that have load-bearing masonry walls. To avoid such issues, reinforced masonry wall can be adopted.

A reinforced masonry wall is made with any type of brick, concrete or another type of masonry materials that strengthened the use of other buildings materials to increase resistance to deterioration due to weight bearing or other forms of stress. Along with usual masonry materials, steel rods are introduced into the structure, often using some type of vertical framework that allows bearing the weight of connecting walls and floors within the building.

The purpose of this type of walls protects the walls from cracks and makes the strength to fight against unexpected earthquakes or other kinds of natural disasters. To defeat these problems, reinforced walls are used; and their quantity and spacing are based on walls and structure conditions. Reinforcement can be used both in horizontal and vertical order at a required layoff.

Materials used for framed structure

  1. Fly ash clay bricks

    Fly ash brick (FAB) is a building material, specifically masonry units, containing class C or class F fly ash and water. The manufacturing method saves energy, reduces mercury pollution, and costs 20% less than traditional clay brick manufacturing. Fly ash bricks are lighter and stronger than clay bricks. Main ingredients include fly ash, water, quicklime or lime sludge, cement, aluminium powder and gypsum. Using these blocks in buildings reduces the dead load (2.6 kg, dimension: 230 mm X 110 mm X 70 mm), allowing one to save around 30 to 35% of structural steel, and concrete. The seepage of water will be reduced due to lower water penetration. It is considered cost efficient as same number of bricks will cover more area than clay bricks and eco – friendly.

  2. AAC blocks

    Autoclaved aerated concrete (AAC) is a lightweight, precast, foam concrete building material suitable for producing concrete masonry unit (CMU) like blocks. Composed of quartz sand, calcined gypsum, lime, cement, water and aluminium powder, AAC simultaneously provides structure, insulation, and fire- resistance. The sizes available for the brick are 600mm x 200mm x 100-225mm. Joint mortar cost is at Rs. 750/ 40kg Bag. Besides AAC’s thermal insulating capability, one of its advantages is quick and easy installation, because the material can be routed, sanded, or cut to size on site using standard power tools with carbon steel cutters. AAC is well suited for high-rise buildings and those with high temperature variations. These bricks are considered environmentally friendly as there is a decrease of 50% of greenhouse gas emissions. One of the disadvantages of AAC brick is that it is known to crack after installation. Mild cracks have been found in the wall constructed with AAC even after plastering and they are brittle in nature

  3. Cellular light weight concrete block

    Cellular Lightweight Concrete (CLC) also known as Foamed concrete is one of the most significant type of concrete used for construction purposes due to its various advantages and usages over traditionally produced concrete.

    Foamed concrete is manufactured by mixing Portland cement, sand, fly ash, water and preformed foam in varied proportions. One of the profound characteristics of specially formulated foamed concrete is the self-compacting property. The density of regular concrete is normally measured at 2400 kg/m³ whereas the density of the foamed concrete ranges from 400 kg/m3 to 1,800 kg/m3. Some of the advantages of using such material are its cost effectiveness, environmental friendliness, fire resistance and thermal insulation.

    Foamed concrete is produced in varied ranges for different purposes:

    1. The lower densities (400 –600 kg/m3): CLC at this range of density are ideal for thermal and sound insulations. They act as resistance against fire accidents, termite and moisture absorbent. They have also proved to be better substitute than glass wool, wood wool and thermocol.

    2. The medium densities (800-1000 kg/m3): This density of foamed concrete in attained for manufacturing pre- cast blocks for non-load-bearing brickwork. The size of blocks may vary based on the design and construction requirements.

    3. The high densities (1200kg/m3 to 1800 kg/m3). This is structural- grade material used for: Construction of load-bearing walls and ceilings of low rise structures, Formation of partitioning walls, Production of pre-cast blocks for load -bearing brickwork.

  4. Rammed earth wall construction

    Rammed earth dates back thousands of years. Many European castles and the Great Wall of China were built using this technology. As the name implies, rammed earth construction involves the use of compressed earth. A mixture of earth consisting of the right amount of sand, gravel and clay is poured into a mould or formwork. This earth mixture is rammed until it becomes rock solid. When properly constructed, rammed earth walls can resist the various onslaughts of nature for a very long time.

  5. Stabilized mud block wall construction

    Stabilization is a technique of improving the properties of mud in such a way that it will possess the adequate wet strength, durability and dimensional stability (retains its shape and size both in dry and moist conditions) without burning. Compacting a mixture of sandy soil with 7% cement and small quantities of lime at optimum moisture in a press results in stabilised mud blocks (SMB). The overall energy consumption in SMB is quite small (about one-third) in comparison with the burnt bricks. Compaction of soil-stabilizer mix can be done by using a manually operated or a mechanised press. The press should be capable of generating sufficient force to produce a dense block. It is advantageous to use a manually operated press to eliminate additional energy needs in terms of electricity or diesel. The blocks have to be cured for three weeks by keeping the block surfaces moist. Additives like fly ash, quarry dust from crushers, granite fines or stone dust from stone cutting and polishing industries and various other mine or factory wastes can be used effectively along with the natural soil.

  6. Burned clay country burned bricks

    Burnt-clay bricks have good resistance to moisture, insects and erosion and create a good room environment. They are medium in cost and have medium-to-high compressive strength. Bricks can be made with sophisticated factory methods, simple labour-intensive methods or a range of mechanized technologies in between. The labour-intensive production methods are most suitable for rural areas where the demand for bricks is limited. The bricks produced by hand will have relatively lower quality, especially compressive strength, and will tend to have irregular dimensions. However, they are economical and require little capital investment or transportation cost. Bricks made in this manner have been used in buildings which have lasted for centuries. Their longevity has depended on the quality of the ingredients, the skill of the artisans and the climate in which they were used.

  7. Inter lock type Porotherm Smart bricks (Brand Weinerberger)

    The Hollow clay blocks by Porotherm Smart Bricks designed to provide better efficiency, durability, ease of use and a host of other benefits that aid in cost- effective wall construction and comes in two types: Non-Load Bearing Clay Hollow Blocks and Load Bearing Clay Hollow Blocks. Under the brand name Porotherm Smart Bricks, Wienerberger India has been producing a range of perforated/ Hollow Clay Blocks that aid in cost effective wall construction. All blocks are available in 3 sizes (400*200*200/150/100) and come in half block version as well.

    Sl.no. Type of wall Sizes available
    1. Load Bearing Wall (Load Carrying capacity 11 N/mm2) 400x200x200
    400x150x200
    400x100x200
    2. Non – Load Bearing Wall (Load Carrying capacity 4.2 N/mm2) 400x200x200
    400x150x200
    400x100x200

  8. Fibre cement boards panels

    V – PANEL: Instant dry wall

    V-panel is a cost effective and time saving solution for construction of dry walls. V-panel has all the advantages of a masonry wall with added qualities preferred for construction. V-panel is a user-friendly product for installation and proves to be a better substitute for conventional walls and any other dry wall solutions.

    V – BOARD

    V-board is non-asbestos, autoclaved, fibre cement board, manufactured using the Hatcheck process and High Pressure Steam Curing (HPSC) technology. V-board has the composite matrix of non-asbestos cellulose fibres, Ordinary Portland cement, fine silica, quartz, fly ash and mineral additives. V-board is manufactured as per IS 14862-2000 norms and it also comes with textured surface finishes, to meet the requirements of modern building applications.

    SCG – Fibre cement boards

    SCG Smart BOARD is a next generation fibre cement sheet with cellulose fibre, Portland cement, silica and other admixtures that are manufactured under a highly controlled environment using the Firm & Flex Technology. The Firm & Flex Technology is achieved with the use of highest grade of raw materials, combined with a highly sophisticated manufacturing process. The Firm & Flex technology of Smart Board and Smart/WOOD system makes them strong and durable and flexible/bendable at the same time. As a building material, Smart/BOARD is the biggest alternate to Natural Wood, Ply board, gypsum board and Wood composite facading materials with a lower price point and performance that is superior to Natural wood, Ply board, gypsum board and Wood Composites. As a building component, Smart board wall system (Smart/walls) is the biggest alternate for a brick or concrete block wall.

  9. FRBL – GLASS FIBRE REINFORCED GYPSUM LOAD BEARING (GFRG) PANELS

    GFRG Panels can be used as load bearing wall panel for construction of buildings up to 6 to 7 stories for residential or commercial purpose without the support of concrete column, bean or slab. The load bearing capacity of the panel is 160 KN per meter. The application of prefabricated Gypsum wall include, Domestic housing, Multi –storied construction, Roofing and compound walls. The Panels can also be used for intermediary floor slab / roof slab in combination with embedded RCC micro-beams and RCC screed concrete. By this process, manpower, cost and time of construction & the use of scarce natural resources like river sand, water, etc. is significantly reduced. 150mm thick @ Rs 950/sqm

Specification of brick wall construction

  1. Bricks shall be laid in English Bond unless otherwise specified and for brick work in half brick wall, bricks shall be laid in stretcher bond.

  2. Half or cut bricks shall not be used except as closer where necessary to complete the bond

  3. All loose materials, dirt and set lumps of mortar which may be lying over the surface on which brick work is to be freshly started, shall be removed with a wire brush and surface wetted.

  4. Bricks shall be laid on a full bed of mortar, when laying, each brick shall, be properly bedded and set in position by gently pressing with the handle of a trowel. It’s inside face shall be buttered with mortar before the next brick is laid and pressed against it. Joints shall be fully filled and packed with mortar such that no hollow space is left inside the joints.

  5. The walls shall be taken up truly in plumb and all courses shall be laid truly horizontal and all vertical joints shall be truly vertical. Vertical joints in the alternate course shall come directly one over the other.

  6. All pipe fittings and specials, spouts, hold fasts and other fixtures which are required to be built into the walls shall be embedded, as specified, in their correct position as the work proceeds

  7. Where bricks cannot be cut to the required shape to form cut corners, cement concrete 1:2:4 (1 cement : 2 coarse sand : 4 graded stone aggregate 20 mm nominal size) equal to thickness of course shall be provided in lieu of cut bricks

  8. New built work shall be covered with gunny bags or tarpaulin so as to prevent the mortar from being washed away.

  9. Vertical reinforcement in the form of bars treated bars considered necessary at the corners and junction of walls and jamb opening doors, windows etc. shall be encased with cement mortar not leaner than 1:4 (1 cement : 4 coarse sand), or cement concrete mix as specified. The dia. of bars shall not be less than 8 mm and concrete grade shall be minimum 1:3:6.

    Cost wise comparison of each material
    Sl.no. Material Source Unit AVG Rate in INR
    1. Cement concrete solid block-300x200x150 Chalakka, Vedimara, Anachal, Mattupuram No.s 29
    2. Cement concrete solid block-300x200x100mm Chalakka, Vedimara, Anachal, Mattupuram No.s 22
    3. Laterite brick Kizhakkambalam, Piravom, Ashtamichira, Mala, Moovattupuzha No.s 40
    4. Wire cut bricks Chovvara No.s 7.8
    5. Porotherm block 400x200x200mm (Load bearing) Palarivattom No.s 89
    6. Porotherm block 400x200x150mm (Load bearing) Palarivattom No.s 73
    7. Porotherm block 400x200x100mm (Load bearing) Palarivattom No.s 55
    8. Porotherm block 400x200x200mm (Non-Load bearing) Palarivattom No.s 79
    9. Porotherm block 400x200x150mm (Non-Load bearing) Palarivattom No.s 63
    10. Porotherm block 400x200x150mm (Non-Load bearing) Palarivattom No.s 45
    11. AAC blocks 600x200x225mm (Brand Fusion) Thoppumpadi No.s 135
    12. AAC blocks 600x200x200mm (Brand Fusion) Thoppumpadi No.s 115
    13. AAC blocks 600x200x200mm (Brand Fusion) Thoppumpadi No.s 88
    14. AAC blocks 600x200x200mm (Brand Fusion) Thoppumpadi No.s 60