Technical Portal for Sustainable Architecture
Anchoring and Bracketing Systems for Ventilated Facades: Building Envelope Engineering
From a structural perspective, a ventilated façade is not simply an aesthetic cladding, but a complex mechanical system that must dynamically interact with the stresses of the building and the elements.
The engineering of anchoring and fastening systems represents the invisible core that guarantees the stability, seismic safety, and long-term durability of every large stone or metal structure. At VM Group, we design and size each substructure to eliminate the risk of stress concentration, optimizing the distribution of static and dynamic loads.
Static Load Management: Fixed Points and Sliding Points
To allow the materials to compensate for the inevitable temperature variations and natural structural settlements of the concrete, the metal substructure must be free from rigid deformations. Our executive design includes a rigorous distinction between the constraint points:
Fixed Points (Load-Bearing Anchors)
They absorb vertical loads due to the cladding's own weight (gravity) and horizontal wind components. They define the facade's geometric alignment.
Non-Bearing / Expansion Anchors
They absorb only horizontal loads (wind thrust and depression), leaving the uprights free to expand vertically. This system prevents parasitic stresses, as rigorously implemented for the differentiated expansions of the Palace of Justice in Florence.
Types of Envelope Fixing: Concealed vs. Exposed Systems
To ensure maximum freedom of expression for the architect without compromising on structural safety, VM Group's engineering team implements various dry and chemical retention technologies, differentiated based on the stratigraphy of the material and the height of the building.
1. Concealed Fixing Systems (Aesthetics and Integrated Protection)
When the architectural language requires continuous, clean, and monumental surfaces, we eliminate any visual metal interference by transferring the retention to the back or inside the panel:
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KERF Technology and Rear Anchors (Undercut): Continuous perimeter milling on the edge of the panel or rear countersunk anchors (such as Fischer FZP) create an invisible geometric mechanical constraint, ideal for large stone masses or thick ceramic tiles.
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To learn more about the application of these technologies to high-quality stone materials, visit the section dedicated to natural stone ventilated facades.
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Mechanical Anchoring with Rear-Slab Anchors (Undercut Technology): A purely mechanical retention system that occurs on the back of the panel. Countersunk holes (geometric non-through holes) are drilled into which special rear expansion anchors (such as Fischer FZP or Keil) are inserted. The anchor locks into place at the bottom of the hole without creating internal stresses in the material, then attaches to the substructure brackets. It is the ideal solution for porcelain stoneware, semiprecious stone, and highly resistant compact materials.
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Certified Structural Bonding: Application of single-component, ultra-high-modulus elastic polyurethane or silicone adhesives (combined with structural double-sided tape for pre-fixation) for the continuous chemical bonding of lightweight slabs and panels. This technology evenly distributes wind stress across the entire surface, eliminating point stress concentrations.
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Inspectable Geometric Interlocking Systems (Buchtal Type): Used for extruded stoneware elements equipped with special longitudinal grooves on the back of the slab. The panel mechanically attaches to horizontal aluminum profiles, ensuring a completely invisible fastening and the unique ability to remove and replace individual slabs at any point on the façade for quick maintenance, without having to dismantle adjacent modules.
2. Visible Fixing Systems (Speed and Mechanical Rigour)
Primarily used for extruded ceramic or stoneware elements. The AISI 304 or 316 stainless steel brackets firmly anchor the edges of the slab, ensuring quick assembly and simplified maintenance of the individual modules.
Seismic Design and Wind Resistance
Each VM Group mounting system is calculated in compliance with current Technical Construction Standards (NTC). The sizing of extruded aluminum or stainless steel brackets takes into account:
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Local seismic action: Calculation of floor accelerations to prevent the panels from detaching in the event of an earthquake.
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Terrain morphology and building height: Evaluation of pressures and strong peak depressions generated by wind in corner areas.
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Integrated Thermal Break: Use of plastic insulation (thermostop) between the bracket and the supporting wall to eliminate local thermal bridges, ensuring maximum energy efficiency of the building envelope.
From Calculation to Construction Site: The VM Group Approach
With thirty years of experience managing large institutional and commercial projects, VM Group does not supply standard components, but develops custom mounting solutions based on precise digital measurements. Each project is validated internally to ensure perfect coplanarity of the planes and effective airflow within the ventilation cavity.
