Question

from this picture, find what size timber will be used for floor joists.

select one:
a. 125 x 125
b. 3.09
c. 240 x 45
d. 190 x 45

Explanation:

Identify the target component

The question asks for the size of the timber used for the floor joists. We need to locate the label pointing to the floor joists in the provided architectural drawing.

Locate the relevant label

Looking at the left side of the drawing, there is a vertical label with arrows pointing to the parallel framing members (joists). The text reads:
"\(240 \times 45\) joists @ 400 crs (4400 max span and 550 max cantilever allowed)."

Extract the timber size

Using the Architectural Drawing Reading and Floor Framing Components knowledge points, we interpret the notation "\(240 \times 45\) joists". The numbers \(240 \times 45\) represent the cross-sectional dimensions of the timber joists in millimeters (depth \(\times\) thickness). Therefore, the size of the timber used for the floor joists is \(240 \times 45\).

Match with options

Let's evaluate the given multiple-choice options:

• a. \(125 \times 125\) (This refers to the piles shown on the right: "125 x 125 piles")
• b. 3.09 (This is part of the detail reference bubble "E / A3.09")
• c. \(240 \times 45\) (This matches our extracted joist size)
• d. \(190 \times 45\) (This refers to the bearers: "2 x (190 x 45) bearer")

The correct option is c.

Answer:

• a. \(125 \times 125\)
• b. 3.09
• c. \(240 \times 45\) (Correct answer)
• d. \(190 \times 45\)