Wood-effect tile grout width: how wide should the joints be?
Materials · 6 min read · updated 17 September 2026 · Written by Tilelico
With wood-effect plank tiles you want a discreet joint so the floor reads as boards. But a 120 cm plank is never perfectly flat: make the joint too thin and every lip shows. The right width is a trade-off between the wood effect and the tolerance of the product.
Free calculator
How much grout do I need?
Manufacturer formula: (L + W) ÷ (L × W) × joint width × depth × 1.6. Add a small reserve for cleaning losses.
Get the exact count with cuts: draw my room →The short answer: 2 to 3 mm indoors
For rectified porcelain planks laid indoors, the most common joint width is 2 to 3 mm.
Non-rectified planks, very long formats and outdoor use call for a wider joint. The manufacturer’s data sheet almost always states a minimum width, and that figure decides.
| Situation | Common width |
|---|---|
| Rectified 15 × 90 or 20 × 120 planks, indoors | 2–3 mm |
| Planks of 150 cm and longer, indoors | About 3 mm |
| Non-rectified planks (rounded edges) | 3–5 mm |
| Outdoor 20 mm wood-effect pavers | 4–5 mm and above |
Continue with: Offset tile layout: half, third or quarter bond? →
Why not go down to 1 mm
A long plank has a slight manufacturing bow: its centre and ends do not sit at exactly the same height. A very thin joint leaves no room to absorb that difference, and any lip catches low-angle light.
The joint also takes up size variation between planks. Across a five-metre row, a tenth of a millimetre per plank adds up if the joint cannot absorb it.
Continue with: Grout calculator: joint width and quantity of grout →
Plank offset and diagonal laying
A half offset puts the centre of one plank beside the end of its neighbour — exactly where the bow is greatest. Many manufacturers therefore limit the offset of long planks to a third or less: check the product sheet before choosing.
Laying wood-effect tiles on the diagonal is possible but multiplies angled cuts along the walls. Allow a larger margin, around 15 %, and plan the layout before ordering.
- One-third offsetThe most common choice: a regular rhythm with limited lipping.
- Controlled randomThe closest look to real boards, provided a minimum distance is kept between end joints in adjacent rows.
- Diagonal or herringboneA strong decorative effect, with more cuts and a set-out that needs careful preparation.
Continue with: Rectangular tile layout: direction, alignment and cuts →
How much grout?
Because planks are long, there is little joint length per square metre. For 20 × 120 planks with a 2 mm joint and 9 mm depth, the manufacturer formula gives about 0.17 kg/m² — barely 3.4 kg for 20 m². A 3 mm joint raises that to about 0.25 kg/m².
The calculator at the top of this page applies the formula to your plank size. Add a small reserve for cleaning losses, and keep perimeter and movement joints in the plan: they are separate from the grout joint.
The figures quoted here describe common practice, not imposed rules. The data sheet for your covering and for your installation products always takes precedence, and measurements taken on site are the reference.
Frequently asked questions
2 mm or 3 mm grout for wood-effect tiles?
2 mm gives the closest look to real boards on rectified planks of ordinary length. 3 mm gives more tolerance on long planks or where the manufacturer requires it. The minimum width on the product sheet decides.
Which grout colour suits wood-effect tiles?
A tone-on-tone grout close to the average plank colour blends into the wood pattern. A contrasting grout outlines every plank and any misalignment.
Does an offset pattern use more grout?
No. Grout quantity depends on plank size and joint width, not on the pattern. The offset changes the cuts, not the joint length.
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Technical references
This guide describes common installation practices. It does not replace applicable technical documents, manufacturer instructions or measurements taken on site.