LEADEN FLOOR - INTOO

Glued — the planks are fully glued to a hard, level, and dry subfloor. This is the thinnest installation method, the one that best conducts heat from an in-floor heating system, and the only one that meets the highest wear-resistance classes. However, it requires a perfectly prepared subfloor, time for the adhesive to dry, and removal is destructive.

Click-lock — the planks interlock using a click system and rest loosely on the subfloor, without glue. This is a floating installation: it accommodates less-than-perfect subfloors, is quick to install, and can be removed without damage, but requires an expansion gap around the perimeter—at least 5 mm for heated floors—and provides slightly better thermal insulation.

Self-leveling — the planks and tiles are held in place by their own weight and by a lightweight adhesive: tackifying adhesive, adhesive underlayment, or a specialized adhesive depending on the subfloor. The existing floor remains accessible; each element can be lifted and replaced. This installation method is ideal for spaces where it is necessary to work beneath the flooring or replace a tile without interrupting operations.

The criterion is not thickness but the usage class (EN ISO 10874 standard): 23 for heavy-duty residential use, 31 to 34 for commercial and retail use, and 41 to 43 for industrial use.

Two key points. The classification also depends on the installation method: at Unilin, the light industrial classification is only certified for fully glued installations. And for offices, it’s the resistance to chairs with casters that matters; this is tested over 25,000 cycles in accordance with ISO 4918.

Yes, this step determines the floor’s lifespan. The subfloor must be firm, clean, dry, and level: Unilin recommends a maximum unevenness of 2 mm when measured with a 2-meter straightedge. If the unevenness exceeds this, the subfloor must be leveled.

Maximum residual moisture content before installation:

• cement screed: 2.0% cement content, reduced to 1.8% if it is a heated screed;
• anhydrite screed: 0.5% CM, 0.3% if heated;
• wood substrate: 10% moisture content.

A porous surface, or a concrete slab in contact with the ground, requires a primer or a moisture barrier. Installation is possible over tile, old compact PVC, or sound hardwood flooring, provided the joints are filled. Installation is not permitted over flexible flooring—such as carpet, needle-punched flooring, or expanded vinyl—or over an existing floating floor.

Yes, all three installation methods are compatible with a water-based floor heating system integrated into the screed. There are two limitations to keep in mind: the surface temperature of the floor must never exceed 27 °C, and the total thermal resistance of the system—including the flooring and underlayment—must remain below 0.15 m²K/W.

The flooring itself accounts for only a small portion of this total—about 0.01 m²K/W when installed without an underlayment—so it is the underlayment for a click-lock installation that must be chosen carefully. A glued floor conducts heat slightly better than a floating floor.

Installation: The heating system should be operational two weeks prior to installation, shut off 24 hours before and during installation, and restarted 48 hours afterward, in increments of no more than 5 °C per day. Cooling is possible if the control system maintains the floor temperature at least 3 °C above the dew point. Electric heating films are only partially compatible; this must be verified on a case-by-case basis.

For daily cleaning, simply sweep or vacuum, and stains can be removed immediately with a damp cloth. For periodic cleaning, use a microfiber mop wrung out as much as possible and a neutral detergent. When using a floor scrubber: use the red pad and very little water.

Avoid: steam cleaners (not recommended by the manufacturer) and household cleaning products such as dish soap, which leave a film that is difficult to remove.

Three precautions can prevent most damage: felt pads under furniture legs; W-type office chair casters in accordance with EN 12529—never use rubber or latex, including rubber-backed mats, which leave permanent stains on vinyl; and an entry mat at least two steps long, which traps about 70% of dirt.

Yes, and that's one of the benefits of LVT: repairs can be made locally, without having to remove the rest of the flooring.

With a floating installation, the tile can be lifted and replaced directly: this is the easiest method for repairs, and the main reason for using this installation method in occupied spaces.

For a glued installation, make a lengthwise cut in the plank using a plunge saw, stopping 10 cm from the ends, then carefully remove the cut material and vacuum the area. Next, cut the grooves in the new plank, apply cold-weld adhesive to the edges, and apply a load of approximately 40 kg for 2 hours.

For a clip-in installation, if the plank is close to a wall, it's faster to unclip the rows up to it; otherwise, use the cutting method described above.

In any case, keep a few samples of each design when you take delivery of the project: manufacturing processes change over time.