When calculating materials and labour hours for the N70 (± 240x70x40, 50 or 65 mm), joint thickness and the specific dimensions of the brick play a role. On site, the maths works out extremely positively, especially when you choose to glue.
The gain: Fewer handling operations per m²
Because the N70 is longer, you systematically handle fewer bricks per square metre. This advantage applies to traditional masonry, but equally extends to thin-bed mortar and gluing. Here is the comparison between the N70 range and equivalent traditional formats (RF 4, WV 50 and WV 65):
| Format | Traditional (±12 mm) | Thin-bed mortar (±6 mm) | Gluing (±4 mm) |
|---|---|---|---|
| N70/4 | ± 80 pcs/m² | ± 92 pcs/m² | ± 96 pcs/m² |
| RF 4 | ± 86 pcs/m² | ± 96 pcs/m² | ± 98 pcs/m² |
| N70/5 | ± 65 pcs/m² | ± 74 pcs/m² | ± 78 pcs/m² |
| WV 50 | ± 75 pcs/m² | ± 87 pcs/m² | ± 91 pcs/m² |
| N70/6,5 | ± 52 pcs/m² | ± 58 pcs/m² | ± 60 pcs/m² |
| WV 65 | ± 58 pcs/m² | ± 65 pcs/m² | ± 68 pcs/m² |
Practical example: A glued facade of 200 m²
To make this efficiency gain tangible, let's look at an average detached house with 200 m² of facade area that is entirely glued. If we compare the N70/5 against a standard WV 50:
- Standard (WV 50): 200 m² x 91 pcs = 18,200 bricks required.
- Narrow format (N70/5): 200 m² x 78 pcs = 15,600 bricks required.
That means handling 2,600 fewer bricks on a single site. The bricklayer has to bend, lift, and place 2,600 fewer times. Because you order in full pallets, the impact on logistics and crane movements is at least as impressive:
- Standard (WV 50): With 374 pieces per pallet, you need 49 full pallets on site for this project. The total delivered weight is 29.1 tonnes (±1.59 kg per brick).
- Narrow format (N70/5): With 552 pieces per pallet, you only need 29 full pallets on site for this project. The total delivered weight is 21.5 tonnes (±1.34 kg per brick).
Choose the N70, and for that exact same facade you have a massive 20 fewer pallets taking up space on site and needing to be moved. On top of that, it saves a total of 7.6 tonnes in freight and lifting work.
Processing on site: Myths debunked
Narrow formats are sometimes surrounded by theories about difficult processing. In practice, however, the N70 proves to be just as workable as a traditional facing brick:
- Speed and alignment: An N70 is laid flush and plumb to the masonry line just as quickly as a WV 50. The contractor does not have to compromise on their familiar working pace.
- Daily build height and 'dancing' bricks: When gluing, the maximum daily build height is a non-issue anyway, as the adhesive sets extremely quickly. Furthermore, at 240 mm, the N70 is 'only' 3 cm longer than a standard Waal format (210 mm). That minimal difference certainly doesn't cause a brick to 'dance' faster. Sinking bricks are almost always the result of mortar being too wet (in traditional masonry), not the length of the brick or the adhesive.
Stability: The impact of wall ties
Because the N70 is narrower (70 mm instead of 90 or 100 mm), regulations require a slight adjustment in anchoring. According to guidelines, this translates in practice to a maximum of one extra wall tie per square metre. Where you would place 5 ties for a standard brick, the N70 requires six. That one extra action per m² is completely negligible in terms of labour hours compared to the time saved by the 2,600 bricks you no longer have to lay.
The final balance for the contractor
Is the N70 more complex or slower to process? Absolutely not. The theory about one extra wall tie per square metre doesn't weigh up against the solid logistical gains on the scaffolding. You need significantly fewer bricks, lift over 7.5 tonnes less weight, and keep the site organised with far fewer pallets. Because the narrow format lends itself perfectly to gluing or thin-bed mortar, the N70 is quite simply a guarantee of higher efficiency and lower physical strain per project.