“Do you want it rectified or non-rectified?” is a question you hear in any tile shop. If you don’t know what it means, you tend to ask for the cheaper one or say yes to whatever the salesperson recommends. Neither is the best strategy.
Rectification matters a great deal in some cases and practically nothing in others. Here’s when it makes a real difference and when you’re just paying more for nothing.
What rectification is
During porcelain tile manufacturing, pieces are fired in kilns at very high temperatures (around 1,200°C). This process produces small dimensional variations: pieces don’t come out exactly identical. Non-rectified porcelain has a manufacturing tolerance of ±0.6 to ±0.8mm.
Rectified porcelain goes through an additional mechanical cutting process with precision machinery that trims the edges, guaranteeing a tolerance of ±0.1 to ±0.3mm.
Why does this matter? Because the grout joint between pieces must compensate for that variation.
The difference in joints
Non-rectified porcelain: minimum recommended joint of 3-5mm.
Rectified porcelain: joint of 1-1.5mm (and in some finishes, down to 0.5mm).
This difference seems technical but has an enormous visual impact. The rectified finish makes the floor appear more continuous, cleaner, more modern. The larger the format, the more noticeable the difference.
When rectification is essential
Large format (+60cm)
With pieces of 60x120cm, 80x80cm or larger, rectification is practically mandatory. Without it, dimensional variations between pieces would create visible discontinuities in the joint.
Designs with little contrast between joint and tile
If you want a tone-matched joint (virtually invisible), rectification is essential.
When it’s not worth it
Small formats (up to 30x30cm)
With 20x20cm or even 30x30cm tiles, a conventional 3mm joint is aesthetically appropriate. Many traditional or artisanal styles actively seek it.
Rustic or intentionally varied styles
Metro tiles, hydraulic tiles, artisanal-effect porcelain tiles are designed to be seen with a visible joint. Rectifying them would work against the style.
Outdoor areas or high thermal variation zones
In outdoor settings, wider joints have a technical function: they absorb differential expansion.
The additional cost
Rectification adds an industrial process to the product, so the price rises. In practice, the difference is around 10-15% over the same non-rectified porcelain. It’s not an enormous cost.
| Example product | Non-rectified | Rectified |
|---|---|---|
| 60x60 mid-range porcelain | €18-25/m² | €20-28/m² |
| 60x120 mid-range porcelain | €28-40/m² | €32-45/m² |
| 80x160 high-end porcelain | €55-80/m² | €60-90/m² |
Brands doing rectification well
Porcelanosa: their large-format collections like L’Antic Colonial or Urbatek are sector references. High quality, price to match (€40-120/m² and up).
Pamesa: Valencian manufacturer with very competitive prices for rectified large format. Their Calacatta and Effect collections are among the most popular for bathroom renovations in Valencia. Range €25-60/m².
Apavisa: specialists in cement, metal and wood effects in large format. Range €30-70/m².
Vives: wide range, good price-design ratio. Range €22-55/m².
Frequently asked questions
Does rectified porcelain scratch more easily? No. The hardness of porcelain (PEI 4-5) has nothing to do with rectification. The process affects the edge, not the surface.
Are 1mm joints harder to keep clean than 5mm ones? They’re actually easier. Less joint surface means less surface to accumulate dirt.
Does the installer charge more for rectified porcelain? Generally yes, especially in large format. The base preparation and flatness control requires more time and precision. The increase is usually 10-20% over standard labour.
If you’re choosing tiles for your renovation, also consult our bathroom tile guide: formats, styles and prices. And to see if rectification fits into your total budget, use our bathroom renovation calculator.
