Demolishing a wall should be carried out in a reasonably organised manner. It’s not simply a question of knocking it down - more one of dismantling it in sections. The reason is simple – safety and forethought. If you simply set to with a sledge hammer giving the result no thought, accidents are much more likely and you’ll also end up with a huge pile of rubble to sort out. Large sections of falling brickwork are dangerous so take it a piece at a time.
Planning the Demolition
In the pictures you can see the wall, on the left, between two properties which needs to be dismantled to make way for a new extension. Under normal circumstances, a wall that is to be demolished would often be done towards the start of the job. However, on this job, there was limited access and storage on site and, as the bricks were mostly to be used as hardcore under the concrete floor of the new extension, the wall was left in place until the area had been cleared ready.
Safety considerations will include checking for dangers such as services, pipe, cables and the like. Notice the white pipe in the picture. You also need to consider where the rubble will fall and what is going to be done with it. If, as in the example pictures, the wall is next to neighbouring property you should discuss the job with them first. You may need access from their side of the wall and you need to make them aware of the potential hazards during the work
Suitable protective gear should be worn – there’s likely to be some flying debris so you should wear safety goggles. A dust mask and work gloves will also be required as well as protective footwear. The same safety gear should be worn by anyone else working with you or in the immediate area.
Demolition and Clearance
The wall should be taken down a section at a time and the rubble sorted and cleared as you go along. Use a club hammer and bolster chisel to break up each part. Hold the blade of the chisel against a horizontal mortar joint one or two courses below the top of the wall and strike the bolster so that it is driven into the bed. A few sharp blows will break the mortar joint and the bricks above will be loosened. Beak vertical mortar joints in a similar fashion and remove the bricks. Repeat this process on horizontal and vertical joints at regular intervals allowing you to remove a few bricks at a time.
With the job in the pictures, some of the bricks were able to be reclaimed. For more info on this, see reclaiming old bricks. But most were to be used for hardcore below the new floor slab. If the broken up wall is to be removed from site, you will need a skip and it’s worth clearing the rubble as you go. This keeps the work area clear. When hiring a skip, go for one with a drop door at one end. You can then easily barrow the rubble into the skip – filling it from the back.
Breaking up a few courses of brickwork at a time will ensure that the rubble is of a manageable size. If the wall were simply knocked down, you’d still be left with large sections and these would be difficult to move until they were broken up further.
If, as on this job, there is limited space, the hardcore can be distributed as the wall comes down. This will save any double handling which would slow the job down. The thickness of hardcore will be detailed in the specification for the job. More hardcore will be needed for this particular job but as a first stage, an even layer of brick was laid across the whole area where the new slab will be. Laying the hardcore evenly leaves a reasonable working area – if it was just slung down any old how the available space for working on the site would be further compromised.
If the wall to be demolished is connected to another wall which is to remain, you will need to take care at the junction. Cut the brickwork carefully at this point so that the remaining wall doesn’t get damaged. Excess vibration as the wall is hit with a sledgehammer can cause cracks and damage to the remaining wall. In the picture you can see the toothed brickwork left where the old wall has come down.
The nature of the job will determine what you do when you get to ground level. On this project you will see that the wall was completely removed below ground as there was a new wall and foundations to be put in here.
Once the wall is down, consideration will need to be given to continued safety around the site. On this project, the wall was on the boundary next to the back door of the neighbour’s house. To safeguard the neighbours, a suitable temporary fence needed to be erected.
Temporary site fencing can be hired. Commonly known as Heras fencing, this is made of large metal mesh panels which stand in heavy base blocks. The blocks are laid at right angles to the fence run so that they cannot tip over. Each panel is secured to the next.