Joint filling, pumps and guns

Machine pointing for masonry is a technology for the rapid and precise filling of joints in masonry structures. It is primarily used in the comprehensive restoration of historic buildings—walls made of Gothic brick, natural stone, or mixed masonry.

The main reasons for using this method:

The need to reduce the time required for the restoration of large surfaces on historic buildings and the need to fill joints after removing degraded mortar.

Classification of methods based on the type of pumping equipment:

Depending on the scale of the project, the specific characteristics, and the grain size of the restoration mortar, we distinguish between:

• Peristaltic pumps —which deliver mortar using a squeezing action—do not heat the material, which is ideal for applying specialized, friction-sensitive restoration mortars.
• Screw pumps – pumps that use a screw mechanism (rotor and stator) to feed mortar.

Selection of Materials and Application Parameters

When machine grouting historic structures, it is crucial to select a material suited to the type of pump and the size of the joints:

• Highly workable restoration mortars: The mixtures (most often based on trass lime) must have exceptionally high workability, stability, and appropriate grain size. High workability allows the mixture to flow through hoses and reduces the risk of blocking.