Clay Bricks: Types and How to Choose Hollow, Perforated or Solid
Types of clay brick: what sets them apart
All clay bricks are made of fired clay, but they are not all meant for the same job. The difference lies in the voids: the more a brick has, the lighter and easier to cut it is; the more mass, the heavier it is and the better the mortar grips. So the useful question is not “which one is best” but “what does this wall have to do”.
The Vetonek range includes six models that cover the usual building and renovation jobs: single hollow brick, double hollow brick, 50 x 20 cm hollow brick, machetón, perforated brick and solid brick. Here is each one, with the data from its technical sheet.
Single hollow brick: thin, light partitions
The Irun single hollow brick measures 32 x 14.5 x 4.5 cm (±10 %) and weighs 1.92 kg per piece. With about 20 pieces per m² and a thickness of just 4.5 cm, it is the choice for interior partitions, wall linings, closing off openings and renovations where every centimetre counts. It is sold by the pallet of 480 pieces (24.12 m²). It is a light partition brick: its technical sheet recommends using anchors made for hollow brick, or reinforcing the area, if you want to hang kitchen units or radiators.
Double hollow brick: “tabicón” and half-brick walls
The Zarautz double hollow brick (24.5 x 11.5 x 8.1 cm, 1.68 kg) has two rows of cavities, which according to its sheet improves thermal and acoustic performance compared with a single hollow brick. It can be laid two ways: “a tabicón”, for partitions of about 8 cm (≈33 pieces/m²), or “a media asta”, for 11.5 cm walls, that is, half-brick walls (≈42 pieces/m²). It suits housing partitions, wall linings, facade cavities and the enclosures of storerooms or garages. It is sold by the pallet of 472 pieces (14.22 m²).
Large-format hollow brick and machetón: fewer pieces per m²
When speed matters, a bigger format helps. The Hondarribia hollow brick in 50 x 20 cm covers 1 m² with only 10 pieces and comes in three thicknesses: 7 cm (about 5 kg), 5 cm (about 3.5 kg) and 4 cm (about 3.2 kg). It also has a small 28 x 12.5 x 4 cm format (about 1.1 kg, 25 pieces/m²) designed for flat renovations. According to its sheet, it is laid with mortar without needing to wet the pieces.
The Eibar machetón brick is a large-format hollow brick with thick walls. Format 33 measures 32.2 x 14.2 x 6.6 cm (2.48 kg, ≈20 pieces/m²) and format 50 measures 48.8 x 19.5 cm with a thickness of 6.8 cm (4.55 kg, ≈10 pieces/m²). At 6.6-6.8 cm thick, it is sturdier than a thin partition and is used for partition walls, wall linings, and enclosures for industrial buildings and technical rooms.
Perforated brick: mass and grip for walls
The Gernika perforated brick (24.5 x 11.2 x 9.5 cm, 2.20 kg) has vertical perforations that the mortar flows into, locking the masonry together. It is heavier than a hollow brick and gives more mass, with better acoustic insulation according to its sheet. It is used for load-bearing walls, party walls, the main leaf of facades to be rendered, pilasters and low walls. It gives ≈36 pieces/m² as a half-brick wall and is sold by the pallet of 360 pieces (9.92 m²). If the wall is load-bearing, always follow the project design: its strength depends on the bond, the mortar and the thickness, not only on the brick.
Solid brick: classic format for renovation and detail work
The Bermeo solid brick measures 27 x 13 x 5 cm and comes in two versions, both with CE marking: solid (about 2.55 kg) and 3-hole perforated (about 2.05 kg). The 3-hole version weighs 0.5 kg less and grips the mortar better; for visible detail pieces, many professionals prefer the solid one. It gives 34.5 pieces/m² in half-brick masonry and is used for load-bearing walls, enclosures, barbecues, chimneys, pillars, arches, low walls and renovation, since its classic format matches existing masonry. It is sold in packs of 150 pieces (4.35 m²) or by the pallet of 306 pieces (8.87 m²).
How to choose by use
- Thin, light interior partition: Irun single hollow brick.
- Partition of about 8 cm or 11.5 cm wall with a double row of cavities: Zarautz double hollow brick.
- Large areas with few pieces: Hondarribia 50 x 20 cm hollow brick or Eibar machetón in format 50.
- Walls with mass, party walls and facades to be rendered: Gernika perforated brick.
- Renovation and detail work in the classic format: Bermeo solid brick.
For partitions we have a dedicated guide: partition walls: hollow bricks and large format. If you are looking for a single-leaf wall, see the guide to the thermal clay block for single-leaf walls. And if you are weighing clay against concrete, compare it with our concrete blocks buying guide. For any load-bearing wall or wall carrying loads, consult the project engineer or architect.
How many pieces per m²?
The yields from the technical sheets are: Irun ≈20 pieces/m²; Zarautz ≈33 pieces/m² “a tabicón” and ≈42 pieces/m² “a media asta”; Hondarribia 10 pieces/m² in 50 x 20 cm and 25 pieces/m² in 28 x 12.5 cm; Eibar ≈20 pieces/m² (format 33) and ≈10 pieces/m² (format 50); Gernika ≈36 pieces/m² as a half-brick wall; Bermeo 34.5 pieces/m² in half-brick masonry. Multiply by the m² of your job and add a margin for cuts and breakage: the Zarautz sheet, for example, suggests allowing 5 % waste. On that basis, 30 m² of partition “a tabicón” with Zarautz needs about 996 pieces, that is, 2 pallets of 472 pieces plus about 50 more.
Frequently asked questions
What is the difference between single and double hollow brick?
A double hollow brick has two rows of cavities and a single one has just one. In the range, the Irun single brick is 4.5 cm thick for thin partitions, while the 8.1 cm Zarautz double brick improves thermal and acoustic performance according to its sheet and can be laid “a tabicón” or “a media asta”.
Which brick is used for a load-bearing wall?
The bricks with more mass, such as the Gernika perforated and the Bermeo solid brick, are the ones their sheets list for load-bearing walls. The final choice still depends on the project, so consult the responsible engineer or architect.
What is a machetón brick?
It is a large-format hollow brick with thick walls. The Eibar machetón comes in format 33 (32.2 x 14.2 x 6.6 cm) and format 50 (48.8 x 19.5 cm, 6.8 cm thick) and is used for partitions, wall linings and enclosures.
How many bricks do you need per m²?
It depends on the model and how it is laid: from 10 pieces/m² for the 50 cm formats (Hondarribia and Eibar) to about 42 pieces/m² for the Zarautz double hollow brick laid “a media asta”. Check the list of yields above and add a margin for cuts.
Do you need to wet bricks before laying them?
It depends on the brick and the weather, so follow the sheet for each model. The Hondarribia hollow brick is laid with mortar without wetting, while for Zarautz and Gernika it is recommended to dampen the pieces slightly in hot weather.
Find every model in the clay bricks and blocks collection and the rest of the range under building ceramics.
