[vijay kasliwal]

Rat-trap bond in wall construction 


This technique is developed by the architect Laurie Baker. The manner in which bricks overlap is called the bond. Stretcher bond (required to construct 125 mm thick partition walls), English bond (walls of thickness 250 mm or more), Flemish bond (decorative bond, used to construct walls of thickness 250 mm or morey) and rat-trap bond are some of the bonds. The rat-trap bond is laid by placing the bricks on their sides having a cavity of 4″ (100 mm), with alternate course of stretchers and headers The headers and stretchers are staggerd in subsequent layers to give more strength to the walls The main advantage of this bond is the economy in use of bricks, giving a wall of one brick
thickness with fewer bricks than a solid bond. 

The main features of rat-trap bond wall are: 
• Strength is equal to the standard 10″ (250 mm) brick wall, but consumes 20% less bricks. 
• The overall saving on cost of materials used for construction compared to the traditional 10″ wall is about 26%. 
• The air medium created between the brick layers helps in maintaining a good thermal comfort inside the building. 
• As construction is done by aligning the bricks from both sides with the plain surface facing outwards, plastering is not necessary except in a few places. The finished surface is appealing to the eye.
• Buildings up to two stories can easily be constructed with this technique. 
• In RCC framed structures, the filler walls can be made of rat-trap bond.

environmentportal.in/files/USE.pdf

[sumit patni]

Rat-trap bond is a type of brick masonry used in wall construction. It is named so because the arrangement of bricks in this bond resembles the shape of a rat trap. The bond consists of alternate courses of headers (bricks laid flat) and stretchers (bricks laid end-to-end) with the headers centered over the joints between the stretchers in the course below.

This bond provides strength and stability to the wall, and it is commonly used in load-bearing walls where the weight of the structure above must be supported. It is also used in walls that require added insulation, as the spaces created between the headers and stretchers can be filled with insulation material.

In rat-trap bond, each header is laid over the center of two stretchers in the course below, and it is bonding into the two stretchers. This interlocking pattern results in a strong bond, making it an ideal choice for load-bearing walls. The bond also provides good stability to the wall by distributing the weight evenly across the wall.

Overall, rat-trap bond is a durable and cost-effective method of wall construction that provides strength and stability to the structure.