Bricks compared

Introduction

Fired bricks are produced using a mixture of clay and water. Units are molded, dried and fired. Brick kilns use a large amount of energy. The clay used in ‘stocks’ often requires extra firing. Flettons use less energy owing to the contribution of burnt impurities inherent in the clay. ‘Mud’ bricks require very little generated energy to manufacture, but large amounts of water. The embodied energy content of mud bricks is potentially the lowest of all building materials but additives, excessive transport and other mechanical energy use can increase the 'delivered' embodied energy of all earth construction.

Key issues

For:
• Durability
• Strength
• Thermal mass
• Accoustic mass

Against:
• High levels of energy used in firing kilns
• Energy used in transportation
• Non renewable resources
• Effects of quarrying and extraction
• Use of cement in assembly

Types of bricks:

Reclaimed bricks
	Reuseable
	Durable
	Non-toxic
	No greenhouse gases
	Very low embodied energy if sourced locally
	High natural content
	Diverts waste from landfill

Ordinary solid clay and stocks
	Reuseable
	Large reserves
	Durable
	Low toxicity
	No greenhouse gases
	High natural content
	High embodied energy

Perforated ordinary clay bricks
	Reuseable
	Large reserves
	Durable
	Low toxicity
	No greenhouse gases
	High natural content
	High embodied energy but lower than solid clay bricks (above)

Unfired 'Mud' Bricks (non load-bearing)
	Reuseable
	Large reserves
	Low toxicity
	No greenhouse gases
	High natural content
	Regulate relative humidity
	Non load-bearing

We would specify:

First Choice: • Locally sourced reclaimed bricks • Unfired bricks
Second Choice: • Perforated ordinary clay bricks • Fletton commons
Mortar: • Use lime mortar - try to avoid cement mortar

Brick products:

• L321 Bricks