External works Flashcards
(40 cards)
What is the purpose of foul and surface water drainage?
To remove wastewater from toilets, bathrooms, kitchens, and rainwater from roofs and hard surfaces.
What are the two UK drainage system methods?
Combined drainage and separate drainage.
What is combined drainage?
A system where both foul and surface water drain into the same sewer.
What are the advantages of combined drainage?
Only one set of infrastructure is needed, lowering construction time and costs; suitable for rural areas.
What are the disadvantages of combined drainage?
Harmful to the environment and more expensive to treat all wastewater together.
What is separate drainage?
A system where foul water and surface water are drained separately.
What are the advantages of separate drainage?
Reduces need for water treatment, lowering environmental impact and cost.
What is a major disadvantage of separate drainage?
Requires two sets of infrastructure, increasing construction costs.
What mistake must be avoided in separate drainage systems?
Connecting foul water to the surface water drain.
What does Building Regulations Approved Document H cover?
Drainage systems, including slope (falls), inspection access, rainwater and foul water drainage, and building over drains.
What is the function of a gully?
Prevents pests and sewer gases from entering buildings.
What is the function of a soil and vent pipe?
Ventilates sewer gases, prevents pressure buildup, and allows smooth sewage flow.
What is the function of an inspection chamber?
Provides access to drains for cleaning and inspection.
What is the difference between a manhole and an inspection chamber?
Manholes are larger and deeper; inspection chambers are smaller and used for shallow systems.
What is the function of a rainwater shoe?
Directs rainwater from downpipes into drains or away from buildings and reduces erosion.
Where are septic tanks commonly used?
In rural areas far from the main sewer system.
How do septic tanks work?
Use anaerobic bacteria to break down solids and organics; treated water is discharged into a drainage field.
What systems are not allowed for septic tank effluent disposal?
Soakaway pits, tunnels, crates, or Ezy Drains.
Where are utilities typically installed?
In pavements along roads, at safe depths from traffic damage.
What are the color codes for utility services?
Water: Blue
Gas: Yellow
Electricity: Black with markers
Telecommunications: Green
How does gas typically enter domestic buildings?
Through an external meter cupboard built into the cavity wall.
What is the minimum depth for water service entry?
750mm to protect from frost.
What is the function of a stop valve?
Shuts off the water supply for maintenance or emergencies.
What is a goose neck?
A curved section of pipe used to relieve stress and allow flexibility.
