Unit 103-Lessons 10

Unit 103 - The Built Environment Life Cycle

​Super Structure

What does the word superstructure mean ?

​Understanding the stages of construction and the installation of services 

​Sub Structure

​Super structure

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

Multiple Choice

In the picture which dimensioned element is specified as 125 × 50?

• Wall plate

• Joists

• Concrete base

• Damp-proof course (dpc)

Multiple Choice

Which combination correctly describes the layer sequence beneath the joists

• Flooring directly over hardcore without concrete base

• Concrete base over hardcore forming the substructure

• DPC below the hardcore and concrete base

• Insulation between joists below the hardcore

​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. 

Multiple Select

Select all statements that are correct for modern solid ground floors as described.

• They include a damp proof membrane and a layer of insulation.

• They commonly suffer rising damp because a DPM is rarely fitted.

• They are built over a concrete slab with layers such as sand blinding and hardcore below.

• They are exclusively used for upper floors due to improved sound 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

Multiple Choice

Refer to the brick bond illustrations. Which brick bond is most commonly used because it is easy to lay with little waste?

• English bond

• Flemish bond

• Stretcher bond

• Header bond

​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  

​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

Multiple Choice

Which statement about sills (or cills) is accurate according to the material?

• Sills are installed above openings to carry masonry loads

• Sills are at the bottom edge of openings and can be made from concrete, stone, or brick, depending on design needs

• Sills are exclusively manufactured from hardwood timber

• Sills are primarily structural lintels with insulation

  ​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.  

Multiple Choice

Identify the truss type best suited for providing usable space within the roof volume.

• Fink truss

• King Post truss

• Attic truss

• Mono truss

​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

Match

Match each roof covering term to its description or common classification based on the text and visuals.

• Slate

• Cement fibre slate

• Roof tiles

• Fiberglass

A natural stone used as traditional roofing

A manufactured sheet mimicking slate appearance

Individual overlapping units often made of clay or concrete

A modern man‑made material used in roofing

• A natural stone used as traditional roofing

• A manufactured sheet mimicking slate appearance

• Individual overlapping units often made of clay or concrete

• A modern man‑made material used in roofing

Match

Match each roof component to its location or function in the hipped roof diagram.

• Ridge board

• Purlin

• Valley rafter

• Wall plate

Horizontal member at the apex receiving rafters

Intermediate longitudinal member supporting rafters

Diagonal rafter forming the internal junction of two roof slopes

Timber fixed to the top of the wall distributing rafter loads

• Horizontal member at the apex receiving rafters

• Intermediate longitudinal member supporting rafters

• Diagonal rafter forming the internal junction of two roof slopes

• Timber fixed to the top of the wall distributing rafter loads

Match

Match each component of a suspended timber ground floor to its typical function.

• Joists

• Wall plate

• Sleeper walls

• Air brick with trunking

Span between supports to carry flooring

Provide bearing surface for joists along walls

Support joists at intervals across the underfloor void

Permit ventilation through to underfloor space

• Span between supports to carry flooring

• Provide bearing surface for joists along walls

• Support joists at intervals across the underfloor void

• Permit ventilation through to underfloor space

Match

Match each floor type to its typical characteristic based on the material described.

• Block and beam floor

• Solid ground floor

• Suspended timber ground floor

• Upper timber floor

Suspended concrete using manufactured beams with infill blocks

Concrete slab on ground incorporating DPM and insulation

Timber structure above ground level supported and ventilated

Timber construction used above the ground storey

• Suspended concrete using manufactured beams with infill blocks

• Concrete slab on ground incorporating DPM and insulation

• Timber structure above ground level supported and ventilated

• Timber construction used above the ground storey