103-4

​Understanding the stages of construction and the installation of services 

​Sub Structure

​Super structure

​Building structure 

​Substructure: 

Anything below ground level is classed as been part of the substructure. ​

​Superstructure: 

Everything structural above ground level is classed as been part of the superstructure.​

​Internal components:

Everything that goes into a building that is nonstructural is classed as an internal component.

​Parts of the substructure: Foundations

​The type of foundation used will depend on the type of building and the ground conditions. The most common types are:

​Strip foundations are widely used for housing and small commercial

developments. The design specification will state the width and depth of

trench that must be excavated to suit the soil conditions and the weight of the

building.

A strip of concrete is poured into the excavated trench to a minimum thickness of

150mm, according to the design. More commonly the thickness will be increased

to 225mm.

​The surface of the concrete should be levelled carefully to allow easier

construction of foundation masonry

​A brick pier or a structural steel column in a steel-framed building will produce

loadings concentrated on a single point. A pad foundation can be designed with

greater depth and additional reinforcement to support this type of load.

When a pad foundation is used to support a steel-framed building, it can have

bolts cast into the top, allowing steel columns to be fixed to it

​​Parts of the substructure: Foundations

​​Parts of the substructure: Foundations

​A raft foundation is often used where a strip foundation would be unsuitable due

to soft ground conditions or where a pile foundation would be too expensive.

It consists of a reinforced slab of concrete covering the entire base of the

building, spreading the weight over a wide area.

​The edge of the slab is usually

thickened as a support for load bearing walls around the face line of a building.
If any minor movement takes place due to poor ground conditions, the building is protected, since the whole foundation can move slightly as a unit

​Cylindrical Pile Foundation

​​​Parts of the substructure: Foundations

Multiple Choice

What type of foundation is shown below?

• Raft

• Pile

• Pad

• Strip

S​uspended timber floor

​A traditional method of constructing suspended ground floors is to use

timber beams called joists, which span the outer walls of a structure.

The joists rest on lengths of timber referred to as wall plates, which in

turn sit on supporting brick sleeper walls built at intervals.

Upper floors are all suspended in that the supporting joists are attached

to or bear on the walls of a structure. There are several ways of linking

the timber joist to the walls to produce a solid and stable result. Steel

connectors and joist hangers in a range of shapes and sizes allow quick

and easy installation of timber beams when constructing upper floors.

Timber floor boarding, or timber sheet material such as a suitable

grade of chipboard, is fixed across the joists to form the floor surface.

​S​uspended timber floor

​Block and beam floor

​'Block and beam’ is a method of producing a suspended concrete

floor that can speed up the process of construction.

It uses factory-manufactured concrete beams that span the walls

of the masonry footings. The shaped beams are carefully spaced to allow dense concrete blocks to be positioned between them.

Provided that the structural strength of the supporting walls is suitable, this method can also be used in upper floors, which has the benefit of providing improved sound insulation.

​Solid Ground Floors

​Types of floors include: solid ground, block and beam, suspended timber ground, upper timber.​ ​ 

Early solid ground floors built in the 1930s to the 1950s had issues with rising damp as many did not have any damp proof membranes fitted. Modern solid floors include a damp proof membrane and a layer of insulation. 

​Parts of the superstructure  

​The superstructure is best described as any part of the building above ground level that bears a live load.
This includes.

​External Walls:
These are constructed usin either brick, block or stone outer leave with lintels and cills forming openings, an inner leave of bricks, blocks or timber frame is secured using brick ties, the cavity between these is filled with insulation.

​Parts of the superstructure  

​Common Brick Bonds

​Stretcher brick bond: is the most common bond. It is easy to lay with little waste and is made of stretcher set in rows, with each course been offset by half a brick. 

​English brick bond: is made up of alternating courses of stretcher and headers. 

​Flemish brick bond: is an alternating layer of heads and stretchers on a single course, with the nest course laid with the header in the centre of the stretcher.

​Parts of the superstructure  

​Common Brick Bonds

​Parts of the superstructure 

​Concrete lintels/ Steel lintels

​Openings in walls for doors and windows must be bridged to support masonry

above them, and this is achieved by installing components called lintels. In the

past, stone beams or hardwood timber beams were used to form lintels. Modern structures use concrete or steel lintels, which are durable and can also have insulation incorporated into them.

​The bottom edge of openings is also an area where moisture can enter the interior of a building. Sills (or cills) are manufactured in a range of designs using concrete, stone or brick, depending on the design requirements.

​​Parts of the superstructure  

​Load-bearing Internal Walls

​Any internal wall that supports the overall structure is known as a load-bearing wall; They normally carry the ends of the upper floor joists.  They are normally constructed using block work; however, bricks and timber framed construction are also used. 

​Parts of the superstructure  

​Timber upper floors need to span the full distance of the room below without any intermediate support, the timber sections need to be able to span this distance and take any loads without failing so are usually a much thicker section size (the building regulations give the sizes to be used). ​ 

​More modern methods include I beams and metal web (posi- joists); these are lightweight engineered alternatives. 

​Parts of the superstructure  

​Roofs

​Flat Roofs

​A flat roof is not literally flat. It must have a slope or incline of up to 10° to

prevent rainwater building up on the surface. Traditionally, the waterproof

coating of a flat roof comprised felt material covered in tar (called

bituminous), built up in several layers. An improved, longer-lasting covering

is provided by layers of glass-fibre sheets impregnated with a special resin.

​Parts of the superstructure  

​Roofs

​Pitched Roofs

​A pitched roof can be constructed with a single sloping surface that leans against

an adjoining wall, appropriately called a ‘lean-to’. This type of roof is commonly

used for porches and extensions to the main building. If a single pitched roof surface

covers the entire building, this is referred to as a mono-pitch roof.

Where a roof has two pitched or sloping surfaces, with triangular walls closing

each end of the roof up to the ridge, this is referred to as a gabled roof, and the

triangular walls are known as gables or gable ends

  ​Parts of the superstructure  

​Traditionally, roofs were constructed on site from individual lengths of timber.

These are referred to as cut roofs because the timber is cut on site to the required lengths and angles to suit the design. This is a process that requires advanced carpentry skills and a good understanding of geometry.

Study the hipped cut roof in to become familiar with the terminology

used for roof components

​Roof components

​​Parts of the superstructure  

​Parts of the superstructure  

​Loads imposed are spread to preventing collapse 

​Parts of the superstructure  

​Truss roofs 

​Trusses are available in many formats to suit the end user, the span and the loads imposed.  

​Roof Coverings

​Roof covers are available in a wide range of material. Traditional locally available materials were used in the past, but today many man-made materials are used, such as clay tiles, slate, concrete tiles, thatch, interlocking metal sheets, fiberglass, and so on. 

​Traditional roof coverings

​New Technologies

​Stairs

​Stairs are designed to allow between floors.  They come in different styles and layouts to fit available spaces.  However, all types must be compliant with building regulation K. 

​Stairs Strings

​The stair string or stringer is the section of timber that is housed to accommodate the treads and risers. 
Each Flight of stairs has two strings. In the image: 

The right-hand string has been cut to follow the treads and risers; this is known as a cut string.  
The left-hand string has an equal width down the full length that encloses the treads and risers; this is known as a closed string  

​Internal Components

​Any component that can be removed without affecting the integrity of the structure is classed as an internal component. These include: 

 

• non-load-bearing partition wall 

 

• plasterboards and plaster 

 

• second fix carpentry: doors, windows, frames, mouldings, fitted units (kitchen, bedroom) 

 

• second fix sanitary ware: toilets, baths, showers, basins, sinks and drainage 

 

• decorative finishes: paint and wall coverings. 

​Sequencing Of Works

​Gantt chart  

​A Gantt chart (named after its inventor Henry Gantt) lists all the tasks needed on the vertical axis and the time intervals on the horizontal axis in hours, days or weeks (dependent on the size of the project). 

Labour plant and equipment can also be shown, allowing for effective planning and ordering of materials. 

Designated time for each task is added during the planning process and the actual times taken during the construction process can be added later. This allows for the necessary actions to be implemented at the right time and any changes can be mitigated to diminish the impact of any delays on the overall project. 

Multiple Choice

What is the purpose of a Gantt chart

• Tell you when breaks are

• Tell you where the toilets are

• Where to sign in on site

• When materials and labour are required on site

​Site Communication

​What is communication and how is it achieved?  

Communication is the process or tool which people use to exchange or pass on information.  

How do we exchange or pass on information?  

There are many ways to communicate. 

Verbal communication is the quickest and most common method of communicating. 

We use speech in two ways:  

• Informally – general conversations with your friends and family etc; chatting to people. 

• Formally – at work, during interviews, on the telephone to customers.  

​Signs and Notices

​Signs and notices are designed to communicate information in a visual format. 

​•      They can cross language barriers through the use of symbols.

•       RAG rated.

•      Show safe exit and escape routes.

•      Are placed in prominent positions and are usually associated with specific H&S issues.

​Other forms of communication

Body language: A non-verbal method that can show an individual’s mood and feelings.

Sign language and gestures: Another non-verbal method of communicating often used to communicate between drivers and banks persons.

Communication channels: Example

Multiple Select

Select two examples of second fix components.

• Door Linings

• Kitchen Units

• Stud Partitions

• Heating Pipes

• Shower Cubicle

Multiple Select

Which two statements are true about verbal communication?

• It has no auditable trail

• It can be misunder stood

• It is recorded for reference

• It crosses language barriers

• It is understood by everyone