Research and Development: counterframe for exterior sliding systems

The outdoor counterframes series by Eurocassonetto, beyond presenting the same characteristics as the indoor series it has got own peculiarities. The inside of the counterframe is covered by a thermal insulating panel wich, in turn, is covered by a mesh suitable for guaranteeing the adherence of the cement mortar. The base of the counterframe is in stainless steel plate in order to avoid any water corrosion. The roller has a standard weight of 120 kg.

Data sheet:

Constructed entirely in first grade 6/10 and 9/10 galvanized plate.

The panels do not have the common vertical folds, but horizontal, more suitable to make the entire structure more solid and robust without annoying swelling of the internal chamber of the counterframe.

The electrowelded mesh is not welded, nor crimped to the panel, with a small tolerance for movement. This tolerance (in case of natural setting of the masonry wall) keeps the central structure from suffering any damage. In fact, the only element in direct contact with the cement mortar is the electrowelded mesh.

The electrowelded mesh (present only in the plaster version) is created with longitudinal and transverse wires 2 mm in diameter. The mesh sheet has no edge closing wires: the ends are formed by “free points” that can move and better align with key points and contact areas on the wall.

The track is made from aluminium extrudate and is completely extractable from the upper headboard. Therefore, unscrewing the butterfly screws from the inside, any necessary modifications can be made without ruining the masonry walls.

It is widely known that interior sliding retractable doors offer considerable advantages over traditional swinging doors: apart from the aesthetic advantages, they make it possible to create multiple environment arrangements, optimizing spaces and ensuring a better use of the paths within a building. The line of Eurocassonetto counterframes for exterior sliding systems transfers these features and advantages to exterior casings as well, while also addressing important issues such as the thermal and acoustic insulation needed to shield buildings from external agents. The following pages are not intended as an exhaustive analysis of a new topic, continually being developed and updated and including other aspects and standards relative to the energy performance of casings and thus also buildings. Instead, it serves as a brief introduction and invitation to discover more about this structural feature, a notion of living and a new concept of the home that is considered here from 5 perspectives.

1. Aesthetics and convenience

Eurocassonetto sliding retractable counterframes for exteriors offer considerable advantages both as concerns aesthetics and convenience. Aesthetically, shutters and/or safety gates, though they often have attractive designs, interfere with the uniform perspective of buildings when open, creating an imbalanced appearance. This is in addition to the fact that, when open, traditional swinging casings occupy space, limit passage and hinder the opening and closing of curtains. On the contrary, with the retractable system the open casing is invisible as it disappears inside the wall and thus in no way compromises the uniformity of perspectives and creates no bothersome obstructions that make it difficult to open and close the same casing. Using retractable casings also makes it easier to create large windows for a more elegant look and enhanced brightness and use of space.

2. Adaptability and versatility

Ideal for any type of building, residential and public, historic and modern, suitable for any type of wall and easily installed both in new and renovated buildings, the versatility of the Eurocassonetto counterframe for exterior sliding retractable systems is one of its essential features. Another strength of the product is its adaptability: the range of doors and windows that Eurocassonetto counterframes can be used with includes both door-windows and windows with single and double doors. Depending on customer needs casings may be used individually (only slide and life, only shutters or only a sliding safety gate) or in various combinations (slide and lift + safety gate, slide and lift + shutters and shutters + safety gate).

3. Resistance and durability

The resistance and durability of counterframes over time is ensured by the quality of materials and their assembly: – the top quality galvanized 6/10 and 9/10 plate used to create the counterframe and stainless steel plate at the base are highly resistant to corrosion; – panels with horizontal folds enhance the hardness and strength of structures; – stapled electrowelded mesh provides considerable tolerance to movement; – rollers have a static load of 120 kg;

The resistance and durability of counterframes were tested at the laboratories of the Certification Authority, “Istituto Giordano”, through a series of product tests:

  • Test report no. 285820 “Determination of the tensile strength of rollers for sliding doors” This test, performed to verify the actual static load, demonstrated that the rollers used in counterframes displayed the first signs of weakness when subjected to an average tensile load of 575 kg, which is much higher than the 120 kg required by the company.
  • Test report no. 285821 “Impact resistance to soft and hard bodies on the simple interior wall according to the UNI 8201:1981 standard” This test was performed to evaluate the resistance of the product to impacts that could accidentally occur in a building. The test, performed according to the requirements of the UNI 8201:1981 standard, involved subjecting the sample to a series of impacts from a hard body weighing 1 kg (steel ball) and a soft body weighing 50 kg (leather casing containing glass balls); impacts were created by dropping the objects on a pendulum from a height of 200 mm for the hard body and 300 mm for the soft body. Upon completion of the test, the sample was checked and displayed: “no damage”.
  • Test report no. 285823 “Mechanical tests on suspending sliding door accessories in accordance with the UNI EN 1527:2000 standard” This test was performed according to the regulations of the UNI EN 1527:2000 standard and aimed to evaluate product resistance over time, particularly for accessory elements such as guides and rollers that are more vulnerable to wear and tear. This included a series of tests that demonstrated product durability over time, even under the harshest usage conditions: Static resistance. Test during which the guides were loaded with a weight of 120 kg (simulating a door) for 15 min with the following result: “permanent deformation = 0”

Life. Test during which the guide-roller system was subjected to a force of 60 kg (hypothetical weight of a casing) for 150,000 opening and closing cycles. The test was completed with no signs of damage apart from “light marks on the wheels of the rollers”, demonstrating how the product, in the hypothetical case in which it undergoes 14 opening-closing cycles per day, can function without problems for thirty years.

Initial friction test before and after 150,000 cycles. Test that determined the force needed to move the casing before performing the 150,000 opening-closing simulation cycles and after when doors may be overloaded due to wear and tear. The test showed that not only was the force needed to move the casing a mere 0.8 kg but that after 150,000 cycles (which correspond to use over thirty years) the force needed remained unchanged, as demonstrated by the product’s high resistance to wear and tear.

4. Thermal performance

Thermal insulation in construction aims to retain heat in buildings in the winter and shield them from heat in the summer. In providing comfortable living conditions, suitable thermal insulation translates into considerable energy savings with a consequential decrease in the relative costs of heating in the winter and cooling in the summer. This is why in Italy, under Legislative Decree no. 311/2006, building energy certification is now mandatory. This decree established the energy performance values that the various structural elements of a building must demonstrate in relation to Italy’s geographical zone. In order to fulfil these needs, Eurocassonetto counterframes for exteriors are equipped with a high powered insulating panel in expanded extruded polystyrene (XPS), 3 cm thick, with a thermal conductivity of λ= 0.037 W/m∙K and thermal resistance of TR = 81.08 sqm K/W, which is positioned on the part of the counterframe facing the interior of the building and thus provides insulation against air flowing through the counterframe, fully exploiting its features.

5. Sound performance

Comfortable living conditions also require sound comfort, particularly when this is compromised by the sound pollution in modern cities produced by excessive exposure to high intensity sounds and noises. Sound insulation in Italy is regulated by Law no. 447/1995, which states that in buildings used for residential, hotel or similar purposes, the sound insulation of the exterior must be equal to at least 40 dB. The tests performed at the technology laboratory “LEGNO LEGNO” focused on a Eurocassonetto counterframe for exterior sliding systems and confirmed compliance with the sound insulation performance and features required by UNI EN ISO 717-1:2007 standard. The test results (test code no. 0062/SI) were excellent as the single counterframe, with the application of a 2 cm layer of plaster in cement mortar, achieved a sound insulation of RW = 45 dB. This value exceeds that required by regulations and does not take into consideration the influence of the masonry structure into which the counterframe is installed (which provides additional sound insulation).