Frequently asked questions
Can it be laid without joints? What minimum joint does Ragno recommend?
No. Ragno expressly declines all responsibility for installation without joints, and treats a 2 mm joint as what it calls a "minimum joint" installation. The manufacturer also points out that you need to allow for structural joints, perimeter joints between floor and wall, the laying joints between one tile and the next, and joints where the ceramic meets other materials.
What condition does the substrate need to be in before laying?
Ragno asks for a perfectly flat laying surface, with a maximum recommended deviation of 3 mm measured under a 2 metre straight edge, properly cured, free of dust and with no visible cracks. The manufacturer also states that the work should be carried out by qualified installers with suitable tools, and advises against laying on a thick bed of fresh mortar for formats with a side longer than 30 cm or on non-absorbent substrates.
When and how should the post-installation clean be done?
According to the manufacturer, washing after installation is an essential stage and is done only once, before the flooring starts to be used. Ragno recommends doing it 4 to 5 days after laying and grouting, and never later than 10 days. Because a film of cement residue is left behind that water alone will not remove, it says to use a diluted acid-based product (1:10 to 1:4 in cold water), wet the surface first and above all the joints, leave it to act for around 2 minutes without letting it dry, remove the solution and rinse thoroughly. The manufacturer advises always testing acid resistance on a loose tile, especially on lapped or polished products, and avoiding cleaners containing hydrofluoric acid (HF) and its derivatives.
Does the floor need treating or sealing? What do you clean it with day to day?
Ragno states that glazed porcelain stoneware needs no protective treatment and that correct, systematic cleaning is enough to keep the surface unaltered. For everyday care it recommends hot water with a mop or a soft sponge and, if needed, neutral detergents. The manufacturer asks you to avoid metal scouring pads and hard brushes, not to use soaps (they tend to leave a sticky film, especially with hard water) or products containing waxes or polishes, and not to apply abrasive detergents to gloss or polished surfaces. Grease and oils are removed with organic solvent or alkaline detergents above pH 9, followed by a good rinse.
I want to lay a rectangular format in a staggered pattern. How far can I offset the tiles?
The manufacturer sets a limit depending on the format. Ragno advises a maximum offset of a quarter of a tile in the formats 15x90, 10x120, 15x120, 20x120, 30x120, 60x120, 58x116, 29x116, 19,5x116 and 14,4x116, and a third of a tile in the formats 14,5x58, 15x60, 30x60, 37,5x75, 29x58 and 20x40. For grouting it recommends working in small areas, 4 to 5 m² at a time, especially with structured, anti-slip and polished products.
What is 20 mm XT20 stoneware and where can it be used?
According to Ragno, XT20 is a full-body coloured porcelain stoneware 20 mm thick, compact and unalterable in structure, intended for outdoor use: terraces, gardens, beaches and swimming pools, and also trafficked, industrial or urban areas. The manufacturer allows for four ways of installing it: dry on grass, dry on gravel, dry on sand, or bonded with adhesive over a screed. Ragno specifies that it is passable for vehicle traffic when installed with adhesive over a screed.