Construction Technology and Building Details

How a building is put together

A low-rise building is built from the ground up, and every part has a job to do. Learn the main elements in order and you can read almost any standard building detail. This module works from the soil to the roof: - The substructure: the foundations below ground that carry the whole building.\n- The walls: built up from the damp-proof course, often as an insulated cavity wall.\n- The floors and roof: solid or suspended floors below, pitched or flat roofs above.\n- The stair rule: the simple sum that keeps a staircase comfortable to climb. Materials, structural forms and drawings each have their own module. Here the focus is how the parts of a building fit together and why each one is there.

Words for construction technology

Five terms you need before you use them. Learn what each one means.

Match each building element to its purpose

Solid floor against suspended floor

A ground floor can be built in two main ways, and each suits different conditions. Knowing the difference is common in the exam.

Which element does this job?

A barrier is built into a wall a little above ground level to stop damp climbing up from the wet soil. What is it?

• A damp-proof course
• A foundation
• A cavity
• A lintel

Tap the two parts of the substructure

Tap the TWO parts that belong to the substructure, below ground.

• The strip foundations under the outer walls
• The hardcore and concrete below the ground floor
• The roof trusses over the top of the house
• The upstairs windows in the outer walls

Building from the ground up

The order in which a building goes up is not random. Each element depends on the one below it, so the sequence itself is worth learning. The foundations come first, spreading the load onto firm ground. The walls rise from the damp-proof course, so no damp climbs into the rooms. The floors go in, then the roof caps it all and throws the rain clear. It is worth knowing that these methods keep changing. Better insulation, and the retrofitting of older buildings to save energy, mean the details of a modern wall or roof differ from those of fifty years ago. The purposes stay the same, but the way we meet them improves.

Pick the true construction facts

Select the TWO statements that are true.

• A cavity wall can hold insulation in the gap between its two leaves
• A pitched roof sheds rainwater faster than a flat roof
• A foundation sits on top of the finished walls
• A damp-proof course is there to let damp rise freely

Order how a low-rise building goes up

Put the stages of building a simple low-rise house in the order they happen.

• Dig and cast the foundations
• Build the walls up from the damp-proof course
• Lay the ground floor
• Add the upper floor and put on the roof
• Fit the windows and doors to weatherproof it

One wall, from footing to eaves

Follow a single outer wall of a house from the ground up, and see how each layer does its job. At the base: the wall stands on a concrete footing, which spreads the weight of everything above it onto firm ground. Just above the soil: a thin barrier is laid right across the wall to stop damp climbing up from the wet earth into the rooms. Rising up: the wall is built as two leaves with a gap between them, and the gap is packed with material that keeps the heat in and the cold out. At the top: the wall meets the roof at the eaves, where the roof oversails to throw rainwater clear of the face of the wall. Four simple ideas, base, barrier, gap and overhang, and the wall stands firm, stays dry and holds the warmth.

Complete the construction technology facts

The part of a building below ground is the _____. A barrier that stops moisture rising up a wall is a damp-proof _____. A wall built as two leaves with a gap between them is a _____ wall. Material placed to slow the loss of heat is _____.

Build a construction point

Choose the words that complete this statement about how a building is built.

Check the stair is comfortable

A stair rule says that a comfortable step satisfies twice the rise plus the going, and the result should fall between 550 and 700 millimetres. A step has a rise of 175 millimetres and a going of 250 millimetres. Work out twice the rise, then add the going. What is the result in millimetres?

Choose the right detail

Read each building problem and choose the detail that solves it, then think about why.

• Damp is rising into the base of a wall from the wet ground. Which detail is designed to prevent this?
• A house is losing too much heat through its outer walls. What helps most?
• A ground floor needs an air gap beneath it to stay dry and ventilated. Which floor suits this best?

Explain how a low-rise building is constructed

A student in the year below does not understand how the parts of a building fit together. Explain it using what this module has covered.

• Explain the difference between the substructure and the superstructure
• Explain the purpose of a foundation and of a damp-proof course
• Explain how a cavity wall helps keep a building warm
• Explain the difference between a solid floor and a suspended floor
• Finish by explaining why the elements must be built in the right order