- Practical advice
- Building materials
- The elevation of the wall
- The steps of the step-by-step assembly of the blockwork wall
- Draw the alignment base
- Lay and adjust the first block
- Make the joints
- Ensuring alignment with a string
- Form chamfers
- Lay intermediate blocks
- Finishing horizontal joints
- Control the plumb
The most common building material, cinderblock is also the cheapest and easiest to implement. In many cases, it replaces the traditional brick, whether to build load-bearing walls, partitions or other fence walls.
Cross-jointing is essential for the solidity of the walls: this is why, every other row, we start with a half-element. The minimum offset must be 1/3 block from one row to the other.
● Do not drown the mortar. The amount of water is half the weight of the cement.
The standard breeze block is "hollow", that is to say, honeycombed so as to make it lighter. The usual dimensions are: 10 x 20 x 50 cm (partitions, non-load bearing walls); 15 x 20 x 50 cm (constructions, garden walls, garage...); 20 x 20 x 50 cm (very strong walls that can support several floors).
In all cases, the elements are assembled with the mortar composed of river sand, a binder (cement, lime or both) and water.
For a 50 kg Cpj cement bag, add 120 liters of sand and 25 liters of water.
The mixing can be done by hand, but it is much more convenient and less tiring to use a concrete mixer.
Provide, in addition to the wheelbarrow, some mason tools: trowel, trowel, plumb line, spirit level, hammer, square, chalk, powder marker, etc.
The elevation of the wall
The technique relates here to the mounting of a basement wall carrier, undertaken as part of a pavilion expansion. The floor slab was poured at the same time as the foundations, which gives a good foundation to the building.
- After determining the limits and squareness of the construction, "beat" the blue wire on the slab to mark markers.
- To work more easily, put a stock of mortar on the trowel.
- Apply the latter on the slab with a trowel, making sure to distribute and chop to promote the attachment.
- Place on this bed a first block of 20 x 2 x 50 cm, cells oriented downwards.
- Adjust your positioning: this starting point is decisive for the rest of the editing.
- Lay the following blocks along the blue line, spacing them approximately 15 mm and checking both plumb and level.
- When the row is complete, fill the joints with a trowel while holding the trowel on one side of the blocks to prevent the mortar from overflowing.
- Equalize with a polystyrene shim.
- Start the second row with half a block at each end, posed well plumb.
- In a palette, there are special elements that split easily in the middle. Connect these end elements by a string of guidance well taut at the top.
- Finished row, grout as before.
- For corner references, there are special blocks to scrape for vertical chaining.
- Otherwise, it will intersect the blocks one rank out of two...
- As the wall rises, often check the horizontality (with a level placed in both directions, longitudinal and transverse), as well as the verticality (plumb line). By proceeding in this way, the regularity of the construction is ensured and this is visible at first glance.
The steps of the step-by-step assembly of the blockwork wall
Practical, the corner blocks allow to achieve vertical chaining. They are hollowed out and are armed with two Ø10 mm concrete rods, alternately oriented, every other row.
Draw the alignment base
Determine a blue line using a powder marker. It will serve as a basis for aligning the first row of blocks.
Trowel and divide a sufficient quantity of mortar.
Lay and adjust the first block
Lay the first block on the mortar bed and check its horizontality in both directions, longitudinal and transverse, and its plumb.
Adjust it with small blows.
Make the joints
Row finished, make the joints.
Fill the interstices with mortar and compact them with a trowel, while applying, as and when, the trowel on one side of the blocks then on the other.
Ensuring alignment with a string
Stretch the string between the blocks of ends of the second row, tie it on the first element pulling hard, then belt the second at the top while blocking the ball.
To obtain a regular bed, spread the mortar with a trowel and then pass the trowel inclined on the edges to form chamfers. This will avoid the fallout by putting the blocks.
Lay intermediate blocks
Present the intermediate blocks and lower them to the cattail until their ridge coincides with the string.
Scrape the mortar overflowing on the sides with the edge of the trowel.
Finishing horizontal joints
Many masons are content to pass the trowel thread over the horizontal joints. A more advanced finish is to make small circular movements with a piece of polystyrene.
Control the plumb
The plumbs of the blocks are checked more frequently with the plumb line than at the level and in several rows. The lead should not touch the wall but deviate a few millimeters.