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We are noticing increasing interest in bonding or thin-bed bricklaying of facing bricks. All our facing bricks are suitable for bonding, thin-bed mortar, and traditional mortar. As long as you use the right mortar. In this article, we would like to explain the different options for laying facing bricks... We recommend that you base your choice mainly on two important factors, namely:

1. the view you wish to obtain
2. the skill of the contractor/builder

Adhesive mortar (3-6 mm)

Bonding facing bricks is becoming increasingly popular. With this technique, the bricks are joined together with a thin layer of adhesive mortar. When bonding facing bricks, the emphasis of the facade's appearance lies in the color and shape of the bricks themselves. The joint is recessed and therefore has a limited impact on the appearance of the façade. The adhesive is applied using a piping bag or a mechanical pump rather than a trowel (as is the case with thin-bed or traditional bricklaying). Adhesive mortar is available in different colors. Often, a tone-on-tone mortar, in the same color as the facing brick, is very attractive. For smooth facing bricks, you achieve the most attractive aesthetic effect with adhesive mortar (compared to thin-bed mortar). Sometimes, the decision is made to leave the butt joints (vertical joints) open. This allows a limited amount of water to enter the cavity, just as with traditional masonry. On the other hand, the open joints ensure that the wall dries out more quickly. You can also choose to seal these joints with adhesive. For example, in the case of shiny insulation that would otherwise be visible, or in the case of a paler adhesive due to the shadow effect in the joint.

Most bricks have a modular bond (2x head or short side + 1 standard joint thickness = 1 stretcher or length brick). For this reason, bonded masonry is usually laid in a random bond.

Advantages

• Certain bonds are easier to achieve due to the strength of the glued joint (e.g., stack bond).
• Larger openings in the wall are possible without support
• The adhesive strength of the glue is significantly higher than that of ordinary mortars.
• The greater adhesive strength allows you to work faster (with experience in the technique) – even though more bricks/m² are required.
• Sustainability: less mortar required compared to traditional joint mortar, which also requires joint filler to fill gaps
• Possibility of prefabrication thanks to the strong adhesive mortar
• Proper execution greatly reduces the risk of efflorescence and lime deposits on the facade masonry.
• Adhesive mortar does not allow water to pass through (traditional masonry mortar and thin-bed mortar do). This ensures that less water enters the cavity and that the bricks dry out more quickly.
• Because there are no joints, the facade dries out more quickly.
• Less chance of moss and algae growth because the stones dry out faster (see points above). Moss and algae mainly grow in damp places. Adhesive mortar is moisture-repellent and there are no joints that absorb water.
• After 24 hours, the adhesive mortar has hardened (compared to 28 days for traditional masonry).
• The facade does not need to be repointed afterwards.
• Modern contemporary look

Disadvantages

• More stones needed / m² (cost price)
• Adhesive mortar is more expensive than traditional masonry mortar (on the other hand, consumption is lower).
• Requires more precise work from the contractor (compared to traditional bricklaying)
• Not every contractor has mastered this technique.
• Dimensional tolerances are more difficult to accommodate: can cause a floating effect with irregular facing bricks
• Even when bonding, the base layer (first layer of bricks) is laid in mortar to compensate for any unevenness. Failure to do so is a common mistake.

Thin brickwork (4-8 mm)

Thin-bed mortar involves working with a very thin joint and using a smaller trowel than in traditional bricklaying. The appearance is almost identical to adhesive bonding, and here too you can choose from a range of colors. However, this mortar is less strong than adhesive mortar in terms of quality. Nevertheless, in certain cases it may be advisable to opt for thin-bed mortar. This is the case for irregular facing bricks, with more size deviations. The extra joint space prevents a 'floating' effect of the facing bricks.

Advantages

• Thin-bed mortar is cheaper than adhesive, while providing the same appearance.
• Due to the slightly greater joint thickness, dimensional tolerances of the facing bricks are better accommodated than with adhesive mortar (more suitable for irregular facing bricks that are not dimensionally stable).
• After 24 hours, the thin-bed mortar has hardened (compared to 28 days for traditional masonry).

Disadvantages

• Not water-repellent: stones dry out less quickly
• In terms of quality, thin-bed mortar does not have the same properties as adhesive mortar: its adhesive strength and water resistance are more similar to those of traditional mortar.

Traditional masonry (100-170 mm)

Traditional brickwork uses a 'normal' joint mortar and joint thickness (+- 1/1.7 cm). The appearance of the facade is determined by the interplay between the facing brick and the joint color. Thirty percent of the color of the facade is determined by the joint, so the color of the joint has a very significant impact on the end result. The appearance is made or broken by the joint color.

Advantages

• This technique is very well known, and you can easily find experienced masons.
• Cheaper than bonding/thin-bed mortar
• Timeless look
• Various options for joining (recessed, flat, brushed, etc.)

Disadvantages

• Not water-repellent: stones dry out less quickly because the joints also absorb water.
• After bricklaying, the joints still need to be grouted.
• After 28 days, the mortar has hardened (compared to 24 hours for thin-bed/adhesive bonding).

One more thing: strike through

Another technique is striking or 'flexible jointing'. This jointing technique is less commonly used in Belgium. It involves laying bricks and jointing in a single operation. This means that so much mortar is used that subsequent jointing becomes unnecessary. This gives the joints a solid appearance and makes them extremely strong.

This technique was used in the restoration of the castle wall in Ingelmunster. Watch the video by Focus WTV here: https://www.focus-wtv.be/video/leerlingen-vti-izegem-bouwen-mee-aan-kasteelmuur-ingelmunster?page=5065  

Decision

Every technique has its advantages and disadvantages. In our opinion, the advantages and disadvantages of traditional bricklaying/bonding balance each other out. In terms of quality, bonding is better than thin-bed bricklaying without subsequent grouting. However, for irregular facing bricks, it may still be advisable to opt for thin-bed mortar to avoid a floating effect.

So let yourself be guided by the view you want to achieve.

In addition, it requires the expertise of the contractor.

Of course, every construction site is unique, and we recommend that you always ask the contractor for a definitive answer.

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