Types of Bonds in Brick Masonry Wall Construction and their Uses

Types of Bonds in Brick Masonry Wall Construction and their Uses

Types of bonds in brick masonry wall construction are classified based on laying and bonding style of bricks in walls. The bonds in brick masonry is developed by the mortar filling between layers of bricks and in grooves when bricks are laid adjacent to each other and in layers in walls.

Mostly used material for bonds in brick masonry is cement mortar. Lime mortar and mud mortar are also used.

Types of Bonds in Brick Masonry Wall Construction :

The most commonly used types of bonds in brick masonry are:

1. Stretcher bond
2. Header bond
3. English bond and
4. Flemish bond

Other Types of bonds are:

1. Facing bond
2. Dutch bond
3. English cross bond
4. Brick on edge bond
5. Raking bond
6. Zigzag bond
7. Garden wall bond

1. Stretcher bond

Longer narrow face of the brick is called as stretcher as shown in the elevation of figure below. Stretcher bond, also called as running bond, is created when bricks are laid with only their stretchers showing, overlapping midway with the courses of bricks below and above.

Stretche bond in the brick is the simplest repeating pattern. But the limitation of stretcher bond is that it cannot make effective bonding with adjacent bricks in full width thick brick walls. They are suitably used only for one-half brick thick walls such as for the construction half brick thick partition wall.

Walls constructed with stretcher bonds are not stable enough to stand alone in case of longer span and height. Thus they Then need supporting structure such as brick masonry columns at regular intervals.

Stretcher bonds are commonly used in the steel or reinforced concrete framed structures as the outer facing. These are also used as the outer facing of cavity walls. Other common applications of such walls are the boundary walls, gardens etc.

Fig-1: Stretcher Bond

2. Header bond

Header is the shorter square face of the brick which measures 9cm x 9cm. Header bond is also known as heading bond. In header bonds, all bricks in each course are placed as headers on the faces of the walls. While Stretcher bond is used for the construction of walls of half brick thickness whereas header bond is used for the construction of walls with full brick thickness which measures 18cm. In header bonds, the overlap is kept equal to half width of the brick. To achieve this, three quarter brick bats are used in alternate courses as quoins.

Fig-2: Header Bond

Fig-3: Header Bond Isometric View

3. English Bond

English bond in brick masonry has one course of stretcher only and a course of header above it, i.e. it has two alternating courses of stretchers and headers. Headers are laid centered on the stretchers in course below and each alternate row is vertically aligned.

To break the continuity of vertical joints, quoin closer is used in the beginning and end of a wall after first header. A quoin close is a brick cut lengthwise into two halves and used at corners in brick walls.

Fig-4: English Bond

Fig-4: English Bond – Isometric View

4. Flemish Bond

For the breaking of vertical joints in the successive courses, closers are inserted in alternate courses next to the quoin header. In walls having their thickness equal to odd number of half bricks, bats are essentially used to achieve the bond.

Flemish bond, also known as Dutch bond, is created by laying alternate headers and stretchers in a single course. The next course of brick is laid such that header lies in the middle of the stretcher in the course below, i.e. the alternate headers of each course are centered on the stretcher of course below. Every alternate course of Flemish bond starts with header at the corner.

The thickness of Flemish bond is minimum one full brick. The disadvantage of using Flemish bond is that construction of Flemish bond is difficult and requires greater skill to lay it properly as all vertical mortar joints need to be aligned vertically for best effects. For the breaking of vertical joints in the successive courses, closers are inserted in alternate courses next to the quoin header. In walls having their thickness equal to odd number of half bricks, bats are used to achieve the bond.

Flemish bonds have better appearance but are weaker than English bonds for load bearing wall construction. Thus, if the pointing has to be done for brick masonry walls, then Flemish bond may be used for better aesthetic view. If the walls have to be plastered, then it is better to use English bond.

Fig-5: Flemish Bond

Fig-6: Flemish Bond Front Appearance

Flemish bonds are classified as:

• Single Flemish Bond
• Double Flemish Bond

Single Flemish bond is a combination of English bond and Flemish bond. In this type of construction, the front exposed surface of wall consists of Flemish bond and the back surface of the wall consists of English bond in each course. Minimum thickness required for single Flemish bond is one and a half brick thickness. The main purpose of using single Flemish bond is to provide greater aesthetic appearance on the front surface with required strength in the brickwork with English bond.

Double Flemish Bond has the same appearance both in the front and back elevations, i.e. each course consists of alternate header and stretcher. This type of bonding is comparatively weaker than English bond.

Methods to Reduce Efflorescence in Newly Constructed Masonry Walls

Satisfactoy implementation of these methods requires extensive knowledge and adequate understanding of each system. Therefore, this article will explore various methods used to decrease potential efflorescence on bricks.

Fig.1: Efflorescence on Brick Masonry Walls

Methods to Reduce Efflorescence in Newly Constructed Masonry Walls

Reduction methods for Potential efflorescence in newly constructed masonry walls are as follow:

• Reduction of water penetration into masonry wall
• Expelling Penetrated or condensed water out of masonry wall quickly
• Prevent the contact between bricks which are different in chemicals composition
• Reduce quantity of efflorescence compounds in materials of masonry wall

Reduction of Water Penetration Especially Wind Driven Rain Water into Masonry Wall

There are several measures which can be used during the construction of masonry walls to decrease water that may ingress the wall. These measures are as follow:

• Form a good bond between masonry units and mortar: A satisfactory bond between masonry units can be obtained if certain construction measures are considered while masonry wall are constructed.
• For example, utilizing mortar compatible with masonry units, fill both bed and head mortar joints sufficiently when solid units are used, adequately fill bed and face shell joints if hollow masonry units are used, consolidate mortar joint from ousted face of the wall.
• Take necessary measures to avoid water penetration, especially rain, into partially constructed walls and wall opening
• Movement joints in the masonry wall should be designed, placed and filled in the best possible way.
• Seal masonry wall-roof interface using flashing.
• Protect masonry wall from rain water by building overhangs.
• It is advised to either add suitable water repellent admixture to concrete masonry units or applying water repellent coating to the concrete masonry wall.
• Masonry building components such as chimney cops, sills and copings should be constructed from solid masonry units, reinforced concrete, corrosion resistant metals or stone.

These components should be extended and exceed masonry wall face by 2.5cm and flashings and weep holes should be provided.

It is recommended to slope (preferably 1:4) these components and attached to the masonry walls. Not only does the movement joints should be properly sized and positioned but also sealed sufficiently.

Expelling Penetrated or Condensed Water Out of Masonry Wall Quickly

Penetrated and condensed water in masonry wall can be discharged by considering the following techniques:

• Installing sound and durable weep holes and flashing at critical location of the masonry wall such as below window copings and sills, above lintels, masonry wall openings, roof-wall intersection and above ground level at the base of the wall.
• Another way to quickly drain water out of masonry wall is through drainage placed in the air space of the drainage wall.

Fig.2: Masonry Wall Drainage System

Prevent the Contact Between Bricks which are Different in Chemicals Composition

Contacts between different bricks in masonry wall can be prevented as follows:

• Install separator between different materials of masonry walls.
• Provide flashing or separator between masonry wall and other structural elements build from different materials for instance chimney caps, sills, and copings.
• If cavity wall is constructed, it is necessary to provide at least 5cm between exterior masonry Wythe and interior wall constructed form different materials.

Reduce Quantity of Efflorescence Compounds in Materials of Masonry Wall

The reduction of efflorescence compounds in materials of masonry walls can be obtained through the following approaches:

• Materials used on the construction of masonry walls such as masonry materials, water, admixtures and cleaning agents are recommended to be tested prior to the masonry wall construction.
• The results of materials tests in combination with construction methods need to be estimated to find out their combine effect on the efflorescence in the future.
• Masonry materials should be stored properly to prevent materials from moisture and contact with dissimilar materials otherwise the likelihood of efflorescence would increase.
• Protect masonry construction materials during delivery to avoid contamination
• If newly constructed masonry walls are cleaned, it is necessary to apply appropriate materials and procedure.