Tweha is first and foremost a bonding expert

However through our experience with many different ventilated facades projects over the years we have also seen which substructures work best and which don’t. Driven by customer demand we have developed our own substructure. Key aspects of our aluminium substructures are: design-freedom.

Tweha has simplified the complexity of facade design

Our aluminium substructures provide maximum flexibility for architecture, design and materials. Whatever the look of a building needs to be, our solution is able to be adapted accordingly. We have come across many systems that didn’t work or where architects had to adapt to the limitations of the system. Thanks to our knowledge and expertise of ventilated facades, we have been able to develop this highly flexible substructure.

Smart fixing system

Tweha’s aluminium substructures have proven its worth for many years in various international projects. Thanks to our smart fixing system installation of our substructures is quick and easy. The smart engineering provides you with the following advantages:

  • Precise adjustment in three dimensions
  • Usability with all insulation material thicknesses
  • Easy bridging of uneven areas or staggered surfaces
  • Tension free installation because of the fixed and sliding points
  • Made of aluminium En-AW 6063, anodised > 20 mu

Sustainable quality

Tweha simplifies the complexity of façade design without compromising on quality. Requirements for facades are very stringent and our solution meets the highest standards. Thanks to the use of durable, corrosion resistant aluminium we are able to create an extremely durable construction. With our static-calculation program, we comply to all required safety requirements and optimise the quantity of fixing elements that are used. This is a major contribution to the economic efficiency of the project. Starting with the static calculations of the project, the installation plans are prepared for clear understanding and clarity, assisting in fast and easy installing. By maintaining an open dialogue with our customers, we are able at the planning stage to point out difficulties and issues; providing solutions and possible improvements. Thus helping to save costs. To help you prepare your plans, we would be happy to provide CAD drawings with system details. In addition, we will give you the appropriate templates for the specification.

Customers benefit from our commitment to high standards of quality and service at all times. All systems are manufactured in accordance with EN 12020 and EN 755 and are statically provable. Of course Tweha is not liable for deficiencies in the façade elements and/or the installation. Local building regulations must be met.

Installing procedure

  1. Gauge the anchoring base to determine the precise projection distance
  2. Mark the drilling positions
  3. Drill the holes according to the dowel manufacturer’s instructions
  4. Install the bracket according to requirements, including the thermal separator
  5. All fixed points are to be installed at the same level
  6. Lay out the thermal insulation
  7. Cut the insulation slabs near the brackets and overlap it over them
  8. The insulation slabs are fastened according to the manufacturer’s instructions
  9. The support profile is inserted into the spring clamp, aligned and then screwed to the brackets. For sliding points one should be aware of the fact that it will be fastened in the middle of the slotted holes.
  10. Cladding slabs must be mounted on the support profiles according to the bonding system manufacturer’s instructions.

Aluminium Surface Treatment

Surfaces do not always need treatment after extrusion. Even before surface treatment, the appearance and surface quality of extruded aluminum profiles is perfectly satisfactory for many applications. Load-bearing structures and machine parts are examples of products where the surface quality is satisfactory without any treatment. Thanks to good corrosion resistance, surface treatment is rarely necessary simply to provide corrosion protection.

So our wall brackets don’t have any surface treatment. Our profiles, because they show through the joints of the cladding, are mostly black anodized.

Anodizing

Anodizing, one of the most common surface treatments, is used to (amongst other things):

  • Maintain a product’s “as-new” appearance.
  • Enhance corrosion resistance.
  • Create a dirt repellent surface that satisfies stringent hygiene requirements.
  • Create a decorative surface with durable colour and gloss.
  • Create a “touch-friendly” surface.
  • Create function-specific surfaces. For example, slip surfaces, abrasion-resistant surfaces for use in machine parts, etc.
  • Give surfaces an electrically insulating coating.
  • Provide a base for the application of adhesives or printing inks.

The anodizing process

There are normally four stages in the process: pre-treatment, anodizing, colouring (where required) and sealing. The most frequent type of anodizing is natural anodizing. The electrolytic process takes place once the metal surface has received the appropriate mechanical or chemical pre-treatment and has been thoroughly cleaned. The profile is connected to a direct current source and becomes the anode (hence anodizing). An electrolytic cell is formed. Dilute sulphuric acid at room temperature is normally used as the electrolyte. During electrolysis, the surface of the metal is oxidized. The process continues until the desired layer thickness (usually 5 – 25 mu) is reached.

Maintenance and cleaning

The anodic oxide layer has good corrosion resistance in most environments. With the proviso that the surface is cleaned, anodized profiles are virtually maintenance-free. The surface cleans easily in both water with a little neutral detergent and in white spirits. Although solvents do not affect aluminium, strong alkaline solutions should be avoided. Resistance to corrosion, discoloration and abrasion increases with layer thickness. Therefore a minimum thicknes of 2 mu is recommendated. As the anodic oxide layer has poor cold formability, forming should take place before anodizing. Cutting and drilling can be carried out after anodizing but the exposed surfaces will, of course, be untreated. Welding is to be carried out before anodizing.

Properties of anodized aluminium

Corrosion resistance is very good, especially where pH is between 4 and 9. In contact with strongly alkaline substances, surfaces can stain and be damaged. Therefore, bear in mind that aluminium should be protected against lime, cement and gypsum (e.g. on building sites). Visible surfaces can be protected using tape. The hardness of the oxide layer depends on the anodizing process used. Generally, the layer is harder than glass and as hard as corundum. The oxide layer is transparent. Whether natural or coloured, its appearance depends on the viewing angle. At temperatures above 100°C, fine cracks form in the oxide layer. From an aesthetic point of view, this may be an undesirable effect. The reflectivity of bright etched aluminum is high. The gloss value is 90 units (ISO 7599, 60° viewing angle). This decreases slightly with anodizing. The oxide layer is an electrical insulator. An anodized profile can be recycled with no pre-treatment. Before remelting, painted profiles must first have the paint removed.