Basic Blockwork PDF

There are two main types of blocks used in the building industry: concrete blocks lightweight insulation blocks. Concrete blocks These blocks are made from concrete. This means they are quite heavy, but they do produce strong finished work. They are used mainly where a lot of weight will be put...

There are two main types of blocks used in the building industry: concrete blocks lightweight insulation blocks. Concrete blocks These blocks are made from concrete. This means they are quite heavy, but they do produce strong finished work. They are used mainly where a lot of weight will be put on top of, or against, the wall. Concrete blocks are also used for forming footings below ground, on walls that support steel, internal walls for car parks and shopping centres, and retaining walls for embankments. These blocks can be solid, hollow or cellular depending on what they are required for. They can also have a finished texture for paint finishes. Solid blocks These are mainly used for making walls above ground for commercial, industrial and leisure buildings. They are used for both internal and external walls. They can also be used for beam and pot floors. They are hard-wearing and provide good fire and sound insulation. Hollow blocks These are used on areas where reinforcement is required. These blocks have the same finish as solid blocks, but have hollow sections in them. They can have reinforcement rods running vertically through them. They are then filled with concrete. This creates a very strong wall and is used in areas where a lot of weight is to be placed on top. It might also be used for other purposes, such as retaining walls for embankments. Hollow block sizes vary from 100 mm up to 215 mm in thickness, depending on requirements. The specification for the job would state the type and size of block needed. Lightweight blocks Concrete manufacturers are now producing lightweight concrete block products. This is because health and safety regulations have placed restrictions on lifting and handling units heavier than 20 kg. The Concrete Block Association, which represents the majority of manufacturers, aims to offer products that would be acceptable to use in order to comply with these regulations. Some manufacturers have reduced the thickness size requirements, while others have substituted hollow blocks in place of thicker solid blocks. Aircrete blocks Aircrete blocks are another kind of block. They are produced under different trade names by several manufacturers. These blocks are made of a microcellular composition called Aircrete. This makes the blocks lightweight but durable. They can be used for most work associated with concrete products. The blocks can be used for foundations, beam and block floors as well as internal and external cavity walling, dependent on the external finishes required. Aircrete blocks have a higher insulation rating than concrete blocks. Their sizes range from 75 mm up to 215 mm for standard blocks. Where are Blocks used in Construction? Foundations Walls Partitions Retaining Structures  Standard Block size? 215mm Other Widths 125mm 150mm 215mm 300m 440mm 100mm  Club hammer Masonry Hand Saw Masonry saw it is use to cut Bolster brick, aerated concrete blocks, and slate. Remember: Wear eye protection when cutting Scutch hammer CALCULATING THE SIZE OF A BLOCK 215mm 10mm 215mm TO ALLOW FOR THE 10mm CROSS JOINT, EACH OF THE TWO HALVES MUST HAVE 5mm CUT FROM THE HALF BRICK LENGTH OF 220mm 220mm 220mm HALF OF A BLOCK IS? (440mm divided by 2) 440mm  CALCULATING THE SIZE OF A ¼ and ¾ BLOCK Quarter block length 100mm, three quarter length is 330mm (REMEMBER TO ALLOW FOR A 10mm JOINT BETWEEN THE TWO CUTS. 100mm 330mm 440mm overall length (Plus the 10mm joint) Session Objectives Understand how to set Define block bonding Learn about the out and establish the and its importance in structural and aesthetic first course of blocks to masonry construction. benefits of proper ensure proper bonding bonding. throughout the wall. Learn the importance Learn the importance of overlapping blocks Define ranging and its of ranging in achieving and maintaining role in ensuring straight accurate alignment in consistent joint and true walls. blockwork. thickness. Understand techniques Define gauging and its Learn to make for checking and significance in adjustments to correct maintaining alignment maintaining consistent deviations in blockwork throughout the course heights in alignment construction process. blockwork. Learn about the Identify tools used for Understand the proper importance of accurate gauging, such as use of these tools to gauging for structural gauging rods, story ensure uniform course integrity and visual poles, and measuring heights. appeal. tapes. Establishing bonds for block walling Bonding is the lapping of bricks or blocks to give a wall maximum strength. Lapping the blocks spreads the weight of the wall. Blocks should be laid so they are bonded for maximum strength to the wall, so they should be laid to half bond or, as in brickwork, stretcher bond. The minimum lap that should be used is quarter bond. 215mm the second course should start with a half block at each end. 215mm in length With half bond, the perp joints of the second course blocks should be in the centre of the block If the wall has a return, the corner blocks should overlap flush and a cut block placed next to it to attain half bond. The cut will vary in size depending on the thickness of the blocks being used Always a quarter block next to the corner block 100mm cut. This illustration shows just where to plumb with this type of wall. As the blockwork courses increase, the ranging must be undertaken. The dotted line in this illustration shows the angle at which to hold your level or straight edge. Ranging ensures that the wall has a flat surface on the face of the blockwork.  Building blockwork course by course requires the bricklayer to gauge the courses. Each course equals 215mm Block plus a 10mm bed joint: 215 + 10 = 225mm. You can use a tape measure as well just need to multiply 225mm 225mm 675mm 450mm 675mm 900mm 450mm 1125mm 1350mm 1575mm 225mm Any Questions?