Both products can be applied for grouting façade files. However, they differ from each other in terms of granulation and scope of application. Fine-grained, ALPOL AZ 150-156 nano-grouts can be used for grouting 2-10 mm wide joints. By contrary, ALPOL AZ 120-126 nano-mortars are a bit more coarse-grained. Hence, apart from their basic application (masonry mortars), they can also be used for grouting 5-30 mm wide joints. Furthermore, given aggregate thickness, the joint being grouted needs to be deeper. It must be noted that in case of using these products a special application method is necessary to grout façade tiles. The method in question is different than the one used for grouting ceramic tiles. You are asked to carefully read a relevant description contained in the product data sheet.
In this particular case, considering the tile width of 6 mm, we recommend using the AZ 150-156 nano-mortar. Additionally, coating the joint with ALPOL AI 780 nano-impregnating agent for mineral surfaces, two weeks after the grouting has taken place, is advised.