FAQ about JVP raised access floor

The Sendzimir hot-dip galvanizing process creates an aesthetic appearance that’s specific to each manufacturer. The appearance is generally quite homogeneous, although there can be variations due to processes, humidity and temperature of the environments where the products are made.

Over time, primarily to comply with increasingly stringent environmental safety standards, new processes have greatly reduced the size of the galvanising “sheets”, so much so that only so-called “micro-spangled” sheets are available for high-quality products on the market today.

Even though quality sheets are all “micro-spangled”, their appearance can differ, especially in terms of shine. These differences become immediately obvious when panels made from sheets of different origins are laid in large rooms.

To avoid this problem and guarantee maximum visual homogeneity, JVP has been using only sheets with a B finish, better known as skinpassed sheets, on the upper visible surface of the panels for some time.

Skinpassing involves calendering the sheets, to “flatten” the galvanizing “micro-spangles” and guarantee an appearance that’s at most a bit opaque but at least very consistent, even between different producers.

While there might still be some slight differences, their frequency and noticeability is very limited, so that they can be considered to meet the strictest standards of homogeneity. In any case, any variations in appearance do not affect product performance in any way.

Thickness, weight and available plenum.

• JVP 4×4 C4TTM000 panels have a total thickness of 29 mm and weigh about 29 kg/m2, guaranteeing a 5/3.0/A/1 load class under UNI EN 12825 (classes increase from 1 to 6), with no need for cross-members: for a finished height of 170 mm, the entire plenum is available for systems for a total of 141 mm;
• Calcium sulphate and fibre panels require a minimum thickness of 34 mm and weigh about 51 kg/m2, guaranteeing a 2/3.0/A/1 load class under UNI EN 12825 (classes increase from 1 to 6). Cross-members at least 30 mm high are required: for a finished height of 170 mm, the plenum available for systems is just 106 mm.

Surface resistance, water and wear resistance

• Bare JVP 4×4 C4TTM000 panels are fully covered with 0.40 mm thick galvanised steel sheet. During construction, they will not chip or stain, and they are fully resistant to scratches, cuts and dents. They do not absorb water and release no dust or debris due to abuse during installation and maintenance;
• Calcium sulphate and fibre bare panels have no mechanical surface protection, so they can chip and stain during construction. They are not resistant to scratches, cuts or dents. They absorb water and release dust and debris due to abuse during installation and maintenance.

Breakage.

• When bare JVP 4×4 C4TTM000 panels break due to loads exceeding the class limit (approximately 1000 kg of incidental load exerted on a 25×25 mm square for class 5), they maintain their integrity because they bend but never break or fragment, so the load never ends up on the underlying slab;
• When calcium sulphate and fibre bare panels break due to loads exceeding the class limit (approximately 600 kg of incidental load exerted on a 25×25 mm ram for class 2), they completely lose integrity because they break and fragment, so the load falls through the entire vertical space of the plenum onto the underlying slab.

All JVP 4×4 systems are composed of three combined elements: pressed-formed galvanised sheet, FSC recycled woodchip core or gypsum fibreboard and a catalysed vinyl-based adhesive to bind them. This creates a galvanised sheet box that wraps the panel completely on all six sides.

Individually, the three basic components have an expected technical life of more than 50 years.

The reference standards for raised technical floors, European UNI EN 12825 and British PSA MOB PF2, which are widely recognised and adopted by the global market, establish no requirements regarding the average life of the products.

However, considering the composition, production technology, laying methodology and locations, which are always indoors and protected from atmospheric agents, indissolubly combined with the strictest respect of the detailed requirements contained in the JVP laying & maintenance manual, the expected minimum lifespan of the JVP 4×4 system is at least 25 years, which JVP normally guarantees.

Not a single product quality complaint has been raised in JVP’s more than 20 years of manufacturing flooring, with over 10 000 000 square meters of JVP 4×4 panels laid.

Experiences also derived from construction sites using systems similar to JVP 4×4 show that lifespans can greatly exceed 25 years in different the geographical locations. More and more often, materials are being recovered and reconditioned for reuse in new construction projects. This is fully in line with our recycling and circularity policy, as a key to future sustainability.

Every commercial type of JVP 4×4 panel is composed of a galvanised sheet capsule that wraps the panel’s inner core of FSC wood chipboard or gypsum fibreboard fully, through gluing and mechanical attachment. This makes them suitable for indoor use only with no direct continuous exposure to water or constant excessive humidity.

DX51D+Z100 sheet metal that is treated with Sendzimir hot-dip galvanisation is suitable only for indoor use with no direct continuous exposure to water or constant excessive humidity.

Not having to use cross-members does have one caveat: the base of the supports must be solidly bonded to the surface of the slab on which they rest. Bonding the supports guarantees vertical stability during normal use of the raised floor, and ensures perfect positioning during inspections or modification.

The quality of the bonding is fundamental for laying and maintenance, which is why we use adhesives with high adhesion and resistance.

The results of bonding and sealing are clearly described in the British PSA MOB PFPS/SPU regulations, specifically dedicated to raised floors, while European UNI EN 12825 regulations are less exhaustive in the matter: our JVP 4×4 system is certified under both regulations and easily exceeds all requirements.

For more information, a copy of articles T14.00 and T15.00 of the PSA MOB PF PS/SPU standard including the testing diagrams are available in English (with a brief translation of T15.00 in Italian).

There is currently no specific codified CE marking procedure for raised floors in Europe, so it is not possible to establish and draft a unified DoP.

All JVP 4×4 systems have undergone significant testing in accordance with European and other sector guidelines, as well as other ancillary and voluntary evaluations for environmental protection and potentially harmful emissions.

The technical data sheets included for all commercial transactions contain the list of relevant standards and the level of performance provided by the JVP 4×4 raised floor system, constituting a sort of DoP, even if this is not codified.

All test reports and third-party certificates proving the truthfulness of JVP technical data sheets are available on our official website www.jvph.net or can be provided on request.

If optimal conditions are not promptly restored after accidental contact with water or excessive humidity, the Z100 galvanizing protection on JVP 4×4 panels can sometimes be triggered, which means the exposed surface will be oxidised to protect the underlying state from corrosion.

This is seen by a variation in the appearance of the sheet metal, with the colour changing to opaque white, sometimes with small quantities of powder. This is irreversible, so the original appearance of the manufactured articles cannot be restored.

However, if the sheet is not too severely affected by oxidation, its mechanical strength is not impacted, so the panel’s general performance is not compromised.

The appearance of initially very small but growing rust spots may indicate that the protective limit has been exceeded, so the steel of the sheet’s body is being attacked. In these situations, the panel’s original performance could be compromised, so it must be replaced.

However, it is important to note that the information above is indicative; occupational safety technicians must assess the objective conditions of each construction site, under their sole responsibility.

JVP 4×4 panels’ galvanised sheet metal receives no subsequent treatment. However, it can be used with no additional covering provided its use is rigorously assessed in light of the considerations below.

The galvanised sheet’s abrasion resistance is known: since the exposed surface is substantially composed of zinc, it has a Mohs hardness of between 2.5 and 3, and the underlying steel has a Mohs hardness of between 4.5 and 5.

It follows that, since the materials normally constituting road and earth dust are crystalline, with a Mohs hardness of 6 or more, the risks of scraping and scratching the bare sheet by walking are considerable.

When considering using unfinished JVP 4×4 panels, it is important to consider the specific non-slip features of galvanised sheet.

JVP has had third-party laboratories perform slip-resistance testing in accordance with the most common international standards, such as ENV 12633:1-2003, BS 7976-2: 2002 and BCRA Tortus method, which are available on request.

In general, Italian regulations accept Tortus results, so galvanised sheet metal is perfectly appropriate for dry and wet rubber soles and critical for dry leather soles. However, the test results must be assessed by occupational safety engineers, under their sole responsibility.

All JVP 4×4 systems are composed of three combined elements: pressed-formed galvanised sheet, FSC recycled woodchip core or gypsum fibreboard and a catalysed vinyl-based adhesive to bind them. This creates a galvanised sheet box that wraps the panel completely on all six sides.

Under normal installation conditions, they are laid bare and the finish is applied later, according to the customer’s technical and aesthetic choices.

Consequently, each panel’s edges are installed against the adjacent panels’ edges, which are also made of galvanised sheet metal.

Thanks to its intrinsic characteristics, galvanised sheet metal does not creak when in contact with another galvanised sheet, except when a different material, such as dust or debris, comes between them.

Sometimes, if the JVP 4×4 floor is not adequately cleaned prior to installation of the final coverings, as required in the laying & maintenance manual, the adhesive can “trap” residue, pushing it into the spaces between the panels and causing creaking.

In this case, to eliminate creaking, the covering may need to be removed, the JVP 4×4 panels lifted and the edges cleaned thoroughly.

The supporting structure of our JVP 4×4 raised floor system requires no connecting cross-members between the heads of the supports.

This is because the unique design and machining of the panel perimeters guarantee considerable mechanical strength when subjected to loads, so they do not need to be reinforced with cross-members.

This makes it much easier to inspect systems beneath the floor; because after lifting the panels, cross-members do not need to be removed, and the entire plenum is usable, with no height reductions generated by the cross-section of the cross-members.

Raised floors with steel panels, the most commonly used type of construction around the world (with millions of square metres laid annually), can receive various types of surface protective treatment, such as painting, electroplating and hot Sendzimir hot-dip galvanizing.

Paint protection may release dangerous fumes in case of fire, while the other two treatments are completely non-combustible.

Some studies opposing “zinc whiskers”, which have not been confirmed by any scientific documentation or backed by limitations imposed by national, European or international harmonised technical regulations, raise doubts about the hypothetical danger of aggregated zinc particles that might be created and then detached by mechanical stresses from the treated surfaces.

While, theoretically, one might hypothesize a possible problem with regard to electroplating done on already finished raw steel pieces, hot-dip galvanization by the sheet metal producers eliminates it entirely.

All of the sheets used in making JVP 4×4 raised floor panels are DX51Z100, i.e. hot-dipped galvanised steel with passivation at the source. This eliminates any possible–even hypothetical–risk of zinc whiskers.