Mechanical Assembly Method Detailed Description
Mechanical assembly refers to the technique of attaching stone cladding materials to building surfaces using stainless steel components known as hooks or anchors. In this system, the weight of each stone is transferred individually to the building surface. This allows for the removal of any stone after assembly without damaging the others, enabling you to leave the spot empty or replace it with another material.
It is important to note that stones should never be attached to the exterior of multi-storey buildings using adhesive methods. Due to factors such as thermal expansion and contraction, as well as potential building settlement and earthquakes, glued stones carry a high risk of falling. The mechanical assembly system employs various anchoring methods based on the characteristics of the surface, the size and thickness of the stone, and the height of the building. This system is specially designed and implemented for each individual building, and it is preferable for all elements to be made of stainless steel. The stainless steel components must meet AISI 316 or 304 quality standards.
### Point Anchor System
This system is divided into two categories: the H-Body Z Anchor system and the Leaf Anchor system. The H-Body Z Anchor system is used on surfaces with load-bearing capabilities (e.g., solid concrete, reinforced concrete walls, columns, beams, etc.). In these cases, Z anchors are mounted directly onto the surface using steel dowels, and each stone is secured to the Z anchors with four stainless pins. The distance between the coated surface and the back of the stone can range from 3 cm to 9 cm.
If the surface to be coated lacks load-bearing properties (such as aerated concrete, brick, or similar materials), and if the stone dimensions are small, the Leaf Anchor system is employed. In this setup, stainless steel flat anchors (Leaf Anchor elements) are fixed in place with mortar, using holes approximately 24 mm in diameter and 70 mm deep drilled into the wall. Each stone is then mounted to these anchors with four stainless pins. In this system, the distance between the coated surface and the back of the stone can range from 1.5 cm to 6 cm.
### Profiled Anchor System
This system is used when the surface to be coated is not load-bearing (e.g., aerated concrete, brick, etc.) and when there is a considerable gap between the surface and the stone for reasons such as insulation, vertical misalignment, or aesthetic considerations. In such cases, profiles are fixed to the reinforced concrete floor beams, with two profiles positioned behind each stone. The coating materials are then mounted to these profiles using Z anchors, similar to the H-Body Z system. The distance between the coated surface and the back of the stone must be at least 7 cm and can extend to a maximum of 22 cm.
### Application Standards
- The thickness of the products to be coated should be a minimum of 2 cm, determined based on whether the wall is load-bearing or non-load-bearing. The dimensions of the coating material (width, length, thickness) should be chosen according to floor heights, openings, and the positions of load-bearing elements.
- The size of the stones should be manageable for the installer, with each stone's area not exceeding 0.5 square meters to facilitate easier installation.
- The shape of the stone should be as close to a rectangle or square as possible, following a 1:2 aspect ratio. Very thin and long stones are prone to breakage.
- When determining the cross-sectional dimensions of the anchor elements, factors such as stone size, stone-to-wall distance, and building height should be considered.
- A ventilation gap must be maintained between the coated surface and the stone. This gap is essential for the mechanical system, promoting natural heat and moisture insulation. Additionally, it can accommodate extra insulation for heat (using extruded polyester material) and water (using a PVC-based membrane).
- Stones should be secured from the bottom and top edges. However, side edge attachment may be necessary in some cases. Keep in mind that the load on each anchor will increase when attaching to the side edges.
- In installations secured from the bottom and top edges, each anchor on the lower edge bears half the vertical load of the stone directly above it, along with half the horizontal load (due to wind pressure and suction).
- The anchor hole for stones fixed from the bottom, top, or side edges should be drilled at a distance of L/4 from the edge.
The anchor element supports the stone above it while simultaneously securing the stone below.
When analyzing the components of the mechanical system, it's essential to consider various factors: the dead load, earthquake loads, as well as the suction and pressure loads caused by wind. Additionally, tensile and pressure assessments should be conducted based on the wind loads.
For material installation, a minimum joint spacing of 5 mm is required both horizontally and vertically.
The steel pins used to secure the stones to the anchors must have a minimum length of 50 mm and a diameter of 5 mm. These pins should be installed with plastic capsules to accommodate any additional stresses that may affect the stone, including thermal expansion, building settlements, and earthquake loads.