Knowledge of materials

Each material has its own physical and technological peculiarities, limitations and capabilities. It is important to know them, as well as their implementation, in order to be able to make projects a reality.

The different building materials

The use of materials, especially traditional ones (stone, earth and wood) has evolved over time. This is why it is important to know the current materials and their specificity.

What are the characteristics for the choice of materials:

Strength, elasticity, rigidity (the ability of a material to deform under a stress of bending, elongation or compression and to return to its original shape when the stress is removed)

Degree of dimensional stability of a material subjected to temperature and humidity variations (important in the choice of connections with other elements and of shaping)

Resistance to water and water vapor of a material intended to be subjected to bad weather or used in humid environments (swimming pools, etc.)

Conductivity or thermal resistance of a material intended for the construction of the external envelope of the work.

Transmission, reflection and absorption capacity of visible light and radiant heat of any material to be used for the finishes

Density or hardness of a material: determining its resistance to wear and abrasion (tiles, for example)

Resistance to combustion, release of fumes and toxic gases, etc …

The weight

What are the different types of bricks


They designate clay-based materials, used for the manufacture of prefabricated elements: bricks and blocks, tiles, bushels, tiles, paving stones, etc.

Terracotta has allowed man to build in all climates and with different kinds of soil. It is the oldest man-made building material. 10,000 years ago the cities were already built of raw earth, dried in the sun. Fired bricks were the first standardized material whose dimensions and weight correspond to easy handling and whose different assembly systems allow the realization of multiple techniques and architectural forms: paired walls, arches and vaults … Its use has varied over time. years and regions, according to traditions and economy. Today, its use is unfortunately limited to simple applications due to ignorance of its potential. In traditional construction, at least in Belgium, all facade or interior walls are built of stone or brick.

Block of terracotta bricks

Advantages: Fire resistant, porosity giving it a certain insulating power (thermal), thermal accumulation capacity (inertia), “breathable” material allowing a hygrometric balance, to a certain extent sound insulating. Lightness compared to concrete masonry (+/- 800 to 1,600 kg / m3).

Types of bricks

in addition to the different types of processing, we distinguish:

Solid bricks – Hollow bricks: recessed in the direction parallel to the laying bed; light and insulating are used for partitions, lining.

Perforated bricks: perforated in the direction perpendicular to the laying bed; for load-bearing and insulating walls.

Facing bricks: for exposed masonry; various formats, colors and aspects depending on the composition of the earth and its cooking.

Insulating bricks: honeycomb structure, interlocking.

Brick chips: thickness 2.3 cm; hand or press molded

Terracotta tiles and shingles

Stretched or molded tiles; they are distinguished by their type of recovery. Their main and primordial quality is of course waterproofing and weather resistance; you can also add flexural strength. The biggest flaw that affects them, regardless of the issues implemented, remains the presence of grain of lime.

Expanded clay

Under the action of high temperatures, certain clays have the property of swelling following the evolution of gas with the softening of the material. After cooling, a light material is obtained with a very marked cellular texture. The expanded clay is then crushed to form aggregates used in the manufacture of concrete and light and insulating mortars.

Tiles – terracotta tiles

Be careful with outdoor use (freezing).


Concrete is an artificial stone material, just like brick. It consists of a mixture:

  • a binder: cement (most often),
  • various mineral aggregates (or aggregates): sand and aggregates
  • of water in sufficient quantity so that the binder takes and binds all the mass.


It is the most common binder although others exist. It consists of a mineral powder which when mixed with water forms a paste which gradually hardens. The hardening therefore takes place under water or in air.

It is used to join the elements together: aggregates, sand and is used in the manufacture of concrete and mortars.

Dosage: ratio between the amount of binder and the amount of sand: to be observed because the strength of the structure depends on it.


Sand, or gravel, is added to the cement paste for making concrete.

The aggregate represents 60% to 80% of the volume of the concrete. The shape of the aggregates has an influence on the stability of the mixture and on the quantity of cement to be used.

 The aggregate must be:

  •  hard,
  • of stable dimensions
  •  free of clay or organic matter which may prevent the binder from binding the particles.


Gravel and crushed stone are the most commonly used aggregates. For certain types of concrete, they are sometimes totally or partially replaced by other so-called artificial aggregates, or even for economic reasons by aggregates from construction debris.

The sand

It must be pure and meet the same criteria as mentioned above. Medium grains are preferred. Its particle size depends on the desired goal.

The water

Used in the mixture must be pure, that is to say free of organic matter, clay, salts and acids. The general criterion is that the water must be drinkable; city ​​water (running water) is perfectly suitable. It is necessary to add a minimum of it in order to obtain a compact concrete. The ratio between the amounts of mixing water and cement determines the strength, durability and impermeability of hardened concrete.

What are the different types of concrete

  • Lean (low dosage of cement, +/- 50 to 100 kg / m3 of cement; little water), low resistance, areas of cleanliness or drainage.
  • Currents: whose resistance reaches 25 to 50 N / mm2 at 28 days and can reach 50 to 100 N / mm2 in 2 or 3 years.
  • High strength: greater than 60 N / mm2 at 28 days; obtained thanks to its components and its implementation.
  • Fiber: improving its tensile strength; aggregates added with reinforcing fibers; example: airport runway, industrial coatings, etc. where high impact resistance is required.
  • Porous or cellular: containing air or gas bubbles. Obtained by adding adjuvant; it has good thermal properties since it is not very dense.
  • Insulation: composed of clay aggregates, expanded glass replacing sand
  • Impregnated with polymers: its porosity is filled with polymerized monomers which makes concrete less deformable and almost impermeable.
  • From polymers: polymer binder; does not withstand more than 100 ° C; used for repairs to reinforced concrete construction or in aggressive environments.