Rat trap bond masonary

1. The first rule of starting any masonary whether exposed or not is to place all the units (bricks, blocks, or stones) in the bond decided all over the plinth even covering the door openings. Remember above the lintel there are in most cases no openings but masonary has to continue.

Here is a picture of a rat trap bond masonary in the starting phase.2. Note there is a header course above the plinth. This course is like a leveling course since

sometime plinth may have exceeded the thickness. It also takes care of the chipping which might be needed for fixing skirting. This header course if the plinth concrete has swelled up is adjusted with stretcher and mortar if need be.

3. Above the header course you can see the beginning of rat trap bond which is a mix of headers and stretchers with the gap due to the bricks having been placed 4.5” height.

4. This needs to be done on all over the plinth including the door openings. The same is to be done without putting in the mortar between the bricks. It is a dry arrangement which will give you the correct mortar thickness to be maintained throughout the building as well as avoid any small or irregular brick sizes.

5. Laying of this course will also allow you to adjust the opening sizes if need be.

In this picture the large frame you see was adjusted as per the brick sizes.6. In the picture below you can see the soldier course as well as opening. You can also note the

solider course below the window. Rat trap bond since it has a hollow it is best to close the same at sill level.

7. If electrical points have been decided run a conduit in the hollows vertically- the best way to not expose the same. Will have to fish out an old photograph but it’s plain common sense-place a conduit vertically bring it to switch box height at a course level place an elbow. Place another conduit with an elbow to continue the wiring to the roof/lintel level wherever the fixture is.

This picture shows some reinforcement but this is the way conduits too stick out.

8. In this picture you can notice as to why the whole bonding must be laid out as the first course after the soldier course. Above lintel there is good clean bond continuing throughout.

9. The t and cross junctions of the bond are available in Laurie bakers’ book. Here is the corner.