Concrete Masonry Blocks

Overview

Engineering reference data for Concrete Masonry Blocks in building construction.

Key Formulas

U-value

$U = \frac{1}{R_{total}}$

Overall heat transfer coefficient.

Heat Loss

$Q = U A \Delta T$

Heat transfer through building envelope.

Variables

Standard Concrete Masonry Unit Dimensions

Standard blocks and half blocks come in various sizes to suit different construction needs. Below are the typical nominal and actual dimensions.

Standard Blocks

Half Blocks

Block Quantity Estimation

A common task is determining the number of blocks required for a wall. The basic estimation formula is:

$$\text{Number of Blocks} = \frac{\text{Wall Area (ft}^2\text{)}}{\text{Block Face Area (ft}^2\text{)}}$$

Where:

• Wall Area is length × height of the wall.
• Block Face Area is calculated from the nominal face dimensions (e.g., for an 8x16 block, the face area is $\frac{8}{12} \times \frac{16}{12} \text{ ft}^2$).

For a more precise calculation that accounts for mortar joints (typically 3/8 inch), use the block's actual face dimensions in the formula above.

References

• Original Source