How to Build a Concrete Wall

HOW TO BUILD A CONCRETE BLOCK WALL

In this video we are going to learn how to build a low concrete block wall.

Concrete blocks are masonry units made from moulded cement. They are evenly shaped and used in the construction of walls.

In this example we will build a low wall of 60cm (23.5in) in height.

Before beginning the construction make sure that the foundations are solid and even.

In order to build a low wall using agglomerate concrete we will need the following: a brush, a trough, a shovel, a trowel, a concrete float, a bucket, a measuring tape, some string, a leveling device, a masonry ruler, a plumb line, a sledgehammer, a mallet and bricklaying gloves.

We will also need:

-hollow concrete blocks with a number of holes.

- corner angle blocks with large circular holes at either end which mean they can be inserted into vertical chains.

- and cement mortar.

First step:

In this video the foundations are made with steel rebars. They strengthen the structure and make the alignment of the wall easier. If you don't use frames you will need to mark the ground with a string line. This will aid you in building a straight wall.

Step two: Humidify the foundation in order to encourage the hardening of the concrete.

Step three: Then spread a layer of mortar and position an angular concrete block at both ends of the wall.

Note that the blocks are always placed with the holes facing downwards.

Make sure it is level and plumb.

Do the same thing at the other end of the wall.

Step four: Now attach a piece of string between the two blocks. It will serve as an alignment guide for the rest of the wall. Check the blocks to make sure they are still aligned.

Step five: Spread around 4cm (1.6in) of mortar. Place the second block in line with the first. Make sure to keep a distance of around 2mm (0.1in) between the string and the blocks.

Step six: Check that it is level and plumb.

Step seven: Pour mortar between the blocks and push it in using the trowel. Also use it in order to smooth the sides of the wall.

Step eight: Continue placing the blocks along the length of the wall.

Measure the level of each block and also use a masonry ruler in order to check the level of the whole wall.

When you come to a gap too small for a block, break a block, insert it and then fill with cement.

Step nine: Once the first level has been built, break a corner angle block in two using the sledgehammer. Hit the grooves found on the underside of the block hard.

Place the half block at one end of the wall and plumb it.

Then, use the plumb to ensure that the block are leveled with the first row.

Do the same thing at the other end of the wall and stretch out the alignment string.

You can keep aligning the blocks by following the previous steps.

You can see that the blocks are aligned and staggered compared to the level below. This step is essential in order to ensure the strength of the wall.

Step ten: When starting the third level continue the staggered pattern by inserting whole blocks at each end.

Keep doing this until you reach the desired height. Remember to check the alignment. the level and that it is plumb.

Alignment, level and plumb

Finish by filling in the rebar holes

Leave it to dry for 48 hours and cut the part of the rebars which sticks out.