Rectified porcelain tile
Rectified porcelain tile is precision-cut after firing to exact dimensions and 90° edges. Allows 1.5-2 mm grout joints vs 3 mm minimum for non-rectified.
Ask Chalkline about this →A rectified porcelain tile is a porcelain tile that has been precision-cut after firing, machining the four edges of each tile to exact, consistent dimensions and 90 degree edges. The result is a tile that can be laid with a much tighter grout joint (typically 1.5 to 2 mm) than a non-rectified equivalent (typically 3 mm minimum), producing a tighter, more contemporary visual result.
Why the distinction matters:
| Tile type | Edge profile | Dimensional tolerance | Min grout joint | Typical use |
|---|---|---|---|---|
| Rectified porcelain | Precision-cut, 90° edges | Within ~0.5% of nominal size | 1.5 to 2 mm | Large-format (600x600 and up), premium residential, commercial |
| Pressed-edge porcelain (non-rectified) | Slightly chamfered / rounded edges, as-fired | Within ~1.5% of nominal size | 3 mm minimum | Volume residential, smaller-format |
| Hand-made / artisan tiles | Variable | High | 5 mm+ | Bespoke residential |
The dimensional variation point. Non-rectified tiles fired in the kiln come out with small dimensional inconsistencies (different rows of the same tile box may vary by 1-2 mm). A 3 mm grout joint hides the inconsistency; a 1.5 mm joint would expose it as visibly uneven lines. Rectified tiles have machined-out variation, so a 1.5 mm joint stays even.
Install rules under AS 3958.1:
- Minimum joint width for rectified tiles: 1.5 mm typical, 2 mm preferred. Going below 1.5 mm risks tile-edge contact (lippage, chipping under thermal expansion).
- Adhesive coverage still 80% walls / 95% floors / 100% wet areas (the rectified status does not change this).
- Tile spacers specifically sized for rectified install (1.5 mm, 2 mm) must be used; the standard 3 mm spacers create the wrong gap.
- Levelling system (lippage-correcting clips) increasingly common on large-format rectified to prevent edge mismatch.
Common defects:
- Rectified tiles laid with 3 mm joints: looks aesthetically wrong for the product; visually mistaken for non-rectified.
- Non-rectified tiles laid with 1.5 mm joints to “save grout”: dimensional variation telegraphs through, ragged lines result.
- Mixed rectified and non-rectified in the same install pattern: joint width has to be the wider of the two; defeats the rectified investment.
- Edge chipping during install from impact with adjacent tiles when joints are too tight.
Cost premium:
Rectified porcelain typically costs 15-30% more per square metre than non-rectified equivalent. The extra step in manufacturing (post-fire machining) adds cost. The cost is paid back on premium projects in faster install time, less wastage at corners, and the visual upgrade.
Also known as: rectified-edge tile; precision-cut porcelain; rectified ceramic.
Category: Materials.
Related
See also
Last updated: 2026-05-16. Verified: 2026-05-16. Quarterly review for currency.