A double-charge vitrified tile is pressed from two layers of powder at once. The top layer is coloured and a few millimetres thick, and the lower layer is a plain base body. The two are fused in the kiln into one porcelain tile.
Because the colour runs a few millimetres deep, a double-charge tile can lose part of its surface and still look the same. That is why it is the common choice for heavy-traffic floors in malls, stations, schools and offices.
How it is made
A special press feeds the mould twice. First it lays the coloured powder for the face, then the base powder behind it. The press compacts both together, so they cannot separate.
The face layer often contains several colours fed in a set pattern. This creates speckled, granite-like or veined looks. After firing, the tile is usually polished to a gloss, or left matt. There is no printed glaze on top, so the pattern is part of the body itself.
Exact layer thickness varies by factory and press. Ask the factory to state it in its data sheet, and check it on a broken sample.
Double-charge vs GVT
- Wear: in GVT the design is in a thin glaze. In double charge it is in the top body layer, so wear shows much later.
- Chips: a chip in GVT shows the body colour. A chip in double charge shows the same colour as the face.
- Designs: GVT can print almost any image. Double charge offers a narrower range of speckled, granite, salt-and-pepper and simple veined looks.
- Water absorption: both are vitrified, group BIa, with 0.5% or less.
- Weight and thickness: double-charge tiles are often a little thicker than GVT of the same size, which affects container loads.
Our article on what GVT is explains the glazed alternative in detail.
Where double charge is used
Double-charge tiles suit floors where wear matters more than variety of design. Common uses include shopping centres, airports and stations, hospitals and schools, office lobbies and factory canteens.
Polished double charge looks good but becomes slippery when wet. For entrances and wet zones, ask for a matt or textured version and a slip test report. For floors with very high traffic, see floor tiles for commercial and heavy traffic areas.
What to check
Not every tile sold as double charge is the real thing. Some suppliers use the name loosely for printed tiles. These checks help:
- Look at the edge of a sample. A double-charge tile shows a distinct coloured layer at the top.
- Break a spare sample and measure the face layer with a calliper.
- Ask for a deep abrasion test to ISO 10545-6, which applies to unglazed tiles.
- Compare the pattern across several tiles. Double-charge designs repeat in a natural, random way, not in a printed face cycle.
Next step
Double charge is a good answer for project buyers who need floors to last. We confirm the factory actually runs double-charge presses, check samples and supervise loading. To plan an order, book a free sourcing review.