Construction Design 1

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Intermediate Floors

The intermediate floors at the site were made up of beams and joists. Beams are singular supporting elements, whereas joints are one of many supporting elements.

This image shows joists, placed with the standard 400mm spacing. The joists are built into the load bearing wall, as displayed in the diagram below.

This image shows a steel beam (red) used in some houses. It is used as a trimming joist to create an opening for the staircase. Therefore, the trimming joist takes the weight of the trimmer joist, which in turn, takes the weight of the trimmed joists. Steel provides greater structural strength than timber. All other bridging joists are timber. The image also shows how the builders construct the floor around a horizontal opening. The diagram below explains the concept behind floor trimming, and its terminology.

To ensure the floor does not bend or twist, whilst the rest of construction continues, it is held up by scaffolding. Whilst the joists and other floor components are still exposed to the elements, they are prone to take in moisture and warp.

Lateral support of joists is provided by strutting. This prevents point loading and twisting of the joists. The houses at the site all used solid strutting. This is less expensive than herringbone strutting and provides less stability, but it is quicker to install. In the image above the strutting can be seen running the length of the floor in three sections. The image below shows the strutting from a side view.