Exposed Concrete Blocks: Smooth and Split-Face, How to Choose

What is an exposed concrete block?

An exposed (fair-faced) concrete block is a concrete block designed to stay on view: the wall is finished as soon as it is built, with no render and no paint. The blocks in the Vetonek range are made of vibro-pressed concrete that is water-repellent (treated to shed water) and coloured through the mass, meaning the colour belongs to the block itself and is not a layer of paint. According to their technical data sheets they can be used both indoors and outdoors.

The first decision is the finish: smooth or split-face. The second is the width and the special pieces you need to close corners, piers and the top of the wall.

Smooth or split-face: what changes

The smooth block has a smooth visible face with clean lines and suits modern or industrial projects. The split-face finish is made by splitting the block: each unit has a rough, irregular face like stone masonry, and no two blocks are the same. For a general comparison, see our concrete blocks buying guide.

The four blocks in the range

• Bloque Briñas (smooth): visible face on both sides and the most complete in sizes. Blocks of 20 × 20 × 40 cm (15 kg), 15 × 20 × 40 (12 kg) and 12 × 20 × 40 (10 kg), and a 10 cm-high partition version: 20 × 10 × 40 (7 kg), 15 × 10 × 40 (6 kg) and 12 × 10 × 40 (5 kg), with half blocks for bonding without cutting. Colours: Sand, Macael White, Tasca White, Cream, Grey and Salmon, depending on the size.
• Bloque Ábalos (split-face): widths of 20 and 15 cm. The 20 × 20 × 40 cm block weighs 17 kg (pallet of 90) and the 15 × 20 × 40 cm block 13 kg (pallet of 120). It includes half blocks and a half block with two split faces for wall ends. Colours: Sand, Macael White, Cream, Grey and Salmon.
• Bloque Rodezno (15 cm split-face): a 15 × 20 × 40 cm block weighing 16 kg (pallet of 100), with a half block, a smooth double corner and a split-face slip in the same product. Designed for light fences, with less weight and less mortar. Colours: Macael White, Cream, Grey and Salmon.
• Bloque Gimileo (three-face split): a 20 × 20 × 40 cm split-face block weighing 18 kg (pallet of 90), plus a version with three split faces and its half block (9.5 kg, pallet of 180) for walls seen from both sides. Colours: Sand, Macael White, Cream, Grey and Salmon.

For the 40 × 20 cm blocks, the coverage given in the data sheets is 12.5 blocks per m² (25 if you use half blocks).

Corners, lintel blocks and copings: the complete system

An exposed block wall is judged by its corners and its top, which is why each family has matching special pieces:

• Corners and lintel blocks for Bloque Briñas: smooth double corners (20 × 20 × 40, 15 × 20 × 40 and the partition version), an external angle block for changes of direction, and U-shaped lintel blocks, the channel for reinforcement and concrete in wall tops, lintels and bond beams.
• Copings and slips for Bloque Briñas: coping with drip groove (9 × 25 × 25 and 9 × 25 × 40 cm) to cap the fence and shed water, an L-shaped end piece for edges and reveals, and a water-repellent slip (4 × 20 × 40 and 5 × 25 × 50 cm) for cladding walls that are already built.
• Corners and end pieces for Bloque Ábalos: a corner with one split face, smooth double corners, an external angle block, U-shaped lintel blocks in 20 and 15 cm, an L-shaped end piece and a 5 × 20 × 40 cm split-face slip.

A tip from the data sheets: work out the double corners before ordering (on a normal fence you get 2 pieces per course and wall end) and order corners and lintel blocks together with the block, because with through-coloured blocks, different production runs can vary slightly in shade.

How to build an exposed block wall

1. Start on a levelled footing or slab.
2. Build in courses with staggered joints in mortar, keeping the joints clean: the visible face is not covered up.
3. Always use the same mortar and point at the same stage of curing so that all the joints have the same tone.
4. Reinforce and fill where the calculation requires it, using the matching lintel blocks.
5. Cap with a coping or a top slab.

With the split-face finish, it pays to mix blocks from two or three pallets as you build, because the texture varies from batch to batch and mixing spreads the shade variations across the whole wall. And keep the three-face block for where it really shows: on a continuous run, the standard block does the same job. The height of the fence, the piers and the reinforcement are set with your project's technician.

How to choose for your case

• Modern fence, sheds and outbuildings, exposed partitions: Bloque Briñas smooth.
• Fence with a stone look: Bloque Ábalos (20 or 15 cm).
• Light fence in split-face: 15 cm Bloque Rodezno.
• Wall seen from both sides or free-standing piers: three-face Bloque Gimileo.

If your project includes changes of level, see also our guide to concrete retaining walls; and if you prefer a brick-style facade, the one on brick-effect stone cladding.

You can see the whole range in the Concrete Blocks and Concrete fencing and enclosures collections.

Frequently asked questions

What is the difference between smooth and split-face exposed concrete blocks?

The smooth block has a smooth visible face with clean lines, while the split-face block is made by splitting the unit and has a rough, irregular face like masonry. In the range, the Bloque Briñas is smooth and the Ábalos, Rodezno and Gimileo blocks are split-face.

Does an exposed block wall need rendering or painting?

No. Because the blocks are water-repellent and coloured through the mass, the wall is finished as soon as it is built and the colour never needs repainting. You do need to keep the joints clean, though, because the visible face is not covered up.

Can exposed concrete blocks be used indoors?

Yes. The data sheets state indoor and outdoor use, and the Bloque Briñas also suggests exposed partitions and low walls indoors with its 10 cm-high partition version.

How many exposed concrete blocks do I need per m²?

For 40 × 20 cm blocks, the data sheets give 12.5 blocks per m², or 25 half blocks. To that you add the double corners and the lintel blocks for the top of the wall, depending on the design of the fence.

What is the three-face split block for?

It lets the stone texture show from every side: it is the piece for wall ends, free-standing piers and walls seen from both faces. The Bloque Gimileo offers it in 20 × 20 × 40 cm, with its half block.

You can see the full data sheets for the Bloque Briñas, the Bloque Ábalos and the Bloque Gimileo at Vetonek, and our team can advise which combination of block and special pieces suits your fence.