Construction Technology

Substructure Insulation DPC Floor Screed Insulation Block work DPM Block work Sand Blinding Ground Level Strip foundation Trench block Cavity fill Brick work Concrete Hardcore Metal reinforcement bar

Substructure- What can you remember?!

Now sketch and annotate a cross section through a substructure

Foundations There are 3 main types of foundation: Strip- Deep Strip- Function: to safely transmit the loads of the building to the soil, to support the loads of the building for it’s lifespan. There are 3 main types of foundation: Strip- Deep Strip- Raft -

Strip- Strip Foundations Advantages: Cheap Brick laying needed Key points to remember: Advantages: Cheap Brick laying needed Disadvantages: Takes longer Dangerous as banks could collapse Will need trench support Wide but not deep

Deep strip Foundations Deep Strip/ Trench fill- Key points to remember: Advantages: Quicker Less chance of bank collapsing Disadvantages: Expensive No brick and block laying needed Very deep- lots of concrete required

Raft Foundations Raft: Key points to remember: Advantages: Ideal for different strength soil Disadvantages: Expensive to build Can crack at weak point Different thickness of concrete

SUPERSTRUCTURES- Roofs Walls Floors Super structures Provide protection from the weather Adds strength and supports the walls of the structure Roofs Walls Super structures Floors Provide protection from the weather Supports the roof and adds stability to the floors Provides support and stability the walls of the structure Supports dead and live loads of a building THEY ALL WORK TOGETHER TO SUPPORT AND STRENGTHEN THE STRUCTURE

Walls OR Most external walls are built using – Bricks and blocks This is rendered blockwork Bricks and blocks OR Name 2 different types of external walls? Discuss the pictures and the different elements of the construction. Timber frames

Types of cavity wall Clear cavity Partial fill Fully fill Name 3 types of cavity construction? Discuss the different types.

Why use Cavity construction? Filled Cavity Partial Filled Cavity Clear Cavity Good as it has a cavity to reduce mortar bridging and damp transfer Bad takes longer as have to clean snots off blockwork Good clear cavity so reduced chance of mortar bridging and damp transfer Bad as no insulation so house loses heat Good for insulation keeps house warmer Bad for mortar bridging and damp transfer What do cavities help to do? How are the 2 skins connected? What helps to prevent moisture from entering the property from the ground?

Cavity Walls Please draw a partial fill cavity wall and label the components using correct architectural symbols.

SIP’s - Structural Insulated Panels These can be used as an alternative to brick and block walls Advantages: Disadvantages: Light so less concrete required in foundations They come pre-insulated so less time wasted on fitting insulation after Faster to build so therefore cheaper Made from wood so will rot over time Will need to apply a finish e.g render They are expensive

Floors Ground Floors   A ground floor is the floor of the lowest level of a building. Ground floors can be either solid or suspended. There are 2 types: Solid Suspended

Solid Floor Solid Floor A solid floor bears directly onto the ground from which it gains its support. It is usually made of solid concrete.   Advantages: Cheap No need for heavy machinery Disadvantages: Takes longer Damp penetration more likely

Suspended Floor  Suspended Floor: A suspended floor is one that is suspended above the ground. It rests on beams spanning between supporting walls. Block and beam floors are commonly used for this type of floor.   Advantages: Quick to construct Can be laid in any weather Reduces the load to the foundation Disadvantages: More expensive Requires machinery to lift heavy beams

Types of suspended floors Advantages: Light, easy to work with, cheap Disadvantages: Not as strong, takes longer to build Timber joists Advantages: Quick to lay in any weather, extremely strong, less foundations required Disadvantages: Expensive, requires a crane to lift them. Pre-cast concrete Advantages: Quick to lay in any weather, extremely strong, less foundations required Disadvantages: Requires a crane to lift and a person to lay blocks Block & beam Name 3 different types of floors? What is the difference between widespan concrete floors and beam & block floors?

Roofs Roof Structure Components of a roof Roofs are designed and constructed to be able to support their own weight as well as resist loads such as wind and snow.   Main functions of a roof: Discharge rainfall away from building Make the building waterproof Look nice Provide extra space for a room or storage

Pitched Roof Pitched roof Advantages: Better water run off Looks nice There are 2 main types of roof: Pitched roof   Advantages: Better water run off Looks nice Storage space Disadvantages: Hard to access and maintain Expensive to build Takes longer to build

Flat Roof Flat roof Advantages: Easy to access and maintain There are 2 main types of roof: Flat roof   Advantages: Easy to access and maintain Cheap to build Quicker to build Disadvantages: Holds water No storage space Requires high maintenance

(how can this be stopped) Risks and hazards There will DEFINITELY be a question on risks and hazards in construction in the exam There are a variety of different risks and hazards present on a building site and a RISK ASSESSMENT is carried out prior to starting work to try and reduce these risks. HAZARD RISK CONTROL MEASURE (how can this be stopped) Collapse of an excavation Injury or death Use of trench supports Safety fences to stop people or machines falling in Ground water Flooding or drowning Use a water pump to pump out water Gas Injury or death via explosion or choking Avoid gas main pipes

Methods of Sustainable Construction: Sustainability A sustainable building is designed and constructed to make as small an impact on the natural environment as possible. Methods of Sustainable Construction: Building on Brownfield sites Recycling and reusing of materials Use of Sustainable materials Use of pre fabricated materials South facing building to make use of natural light Sustainable materials Sheep’s wool- insulation Lime- mortar Straw- walls and plaster Softwood- timber frames Aluminium- guttering

LAST QUESTION- worth 8 marks and is very important part of the exam Q: A builder wants to build a house and is unsure whether to use brick and block cavity wall or SIP’S. How to answer this question…… Masonry wall SIP’s- Structural Insulated Panel ADVANTAGES DISADVANTAGES Has a cavity so less chance of damp transfer Can take a long time to build Brick work looks a lot nicer Heavy so more concrete needed in foundations ADVANTAGES DISADVANTAGES They come pre made so saves time building The timber will rot over time They are light so less concrete required in foundations. Not as nice looking as brickwork In conclusion I believe the masonry wall to be the most appropriate for the builder to use brick work because there is less chance of damp transfer compared to the SIP’S. Also the brick work will look a lot nicer than using SIP’S. He would have problems with the SIP’S because they will rot over time and he would have to spend more money to replace it where brick work will be there forever.