Domakihub How to Grout Floor Tiles: A Step-by-Step Guide
Get clean, durable grout lines every time with the right technique and materials.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
Grouting is the final and most visible step in a tile floor installation, and doing it well makes the difference between a professional-looking result and one that looks rushed. The video above walks through the full process visually, while this guide breaks down every stage into clear, repeatable steps suited to homes, holiday rentals, offices, and hotels across Greece. Whether you are finishing a kitchen, bathroom, or terrace, the same fundamentals apply.
Choosing the Right Grout for Your Floor
Grout comes in two main types: cement-based (sanded or unsanded) and epoxy. Sanded cement grout is used for joints wider than 3 mm and is the standard choice for most floor tiles; unsanded grout is for narrower joints and polished surfaces that could be scratched by sand particles. Epoxy grout costs more but is highly resistant to staining, moisture, and chemical cleaners, making it a smart choice for commercial kitchens, hotel bathrooms, or any floor that will see heavy use and regular mopping with strong agents.
In Greece the climate matters: outdoor terraces and balconies exposed to sun, rain, and freeze-thaw cycles benefit from a flexible, polymer-modified cement grout rather than a rigid standard mix. Always check the tile manufacturer's recommendation for minimum and maximum joint width, as grouting too narrow a joint can crack and grouting too wide a joint with the wrong product will lead to shrinkage and crumbling.
When to Call a Professional
Grouting itself does not require a permit or a licensed tradesperson in Greece, and a careful DIYer can achieve excellent results. However, if the floor system underneath shows signs of damp penetration, structural cracking, or deflection, those issues must be resolved before any tile or grout work begins. Waterproofing wet areas such as shower floors and terraces requires a continuous membrane and, in multi-unit residential buildings, must often comply with fire and water isolation regulations — in those cases a licensed tiler or civil engineer should be involved.
If you are working in a heritage building or a property under a planning consent, check with your municipality before undertaking any floor replacement, as some interventions require a small-scale works permit (mikri adeias) from the local planning authority.
How to Grout Floor Tiles: 5 Steps
- 1
Prepare the Surface and Check Curing Time
Before opening a bag of grout, confirm the tile adhesive (cement mortar or tile adhesive) has fully cured — typically 24 hours minimum, or 48 hours for large-format tiles or high-movement substrates. Remove all tile spacers. Vacuum out each joint thoroughly; any dust, adhesive lumps, or debris will weaken the grout bond and cause premature cracking. Lightly dampen the joints with a brush or spray bottle if using cement grout, but do not leave standing water.
- 2
Mix the Grout to the Right Consistency
Pour the measured water into a clean bucket first, then add the grout powder gradually while mixing with a margin trowel or a slow-speed drill with a paddle attachment. Aim for a peanut butter consistency — the mix should hold its shape, not slump or run. Allow the grout to slake (rest) for 5-10 minutes after initial mixing, then briefly re-stir. Never add extra water to a stiff mix after slaking; this weakens the finished grout by raising the water-to-cement ratio.
- 3
Apply Grout with a Float Across the Joints
Load a rubber grout float with grout and spread it diagonally across the tile surface in sweeping arcs, pressing firmly to pack the joints completely. Work in manageable sections of about 1-2 square metres at a time — especially important in warm Greek summers where cement grout can skin over quickly. Hold the float at roughly 45 degrees to the surface to avoid dragging grout back out of the joints. After packing, sweep the float at a near-vertical angle to remove most of the excess grout from the tile faces.
- 4
Clean the Tiles Before the Grout Sets
Wait 10-20 minutes (less in hot weather) until the grout is firm but not yet hard, then wring out a large sponge in clean water until it is barely damp. Wipe the tiles in a circular motion first to break up the grout film, then follow with diagonal strokes to avoid pulling grout from the joints. Rinse the sponge frequently and change the water often — dirty water smears rather than cleans. Expect to make two or three passes. A final light haze will remain on the tile surface; buff this off after the grout hardens (usually after another 1-2 hours) using a dry microfibre cloth.
- 5
Cure, Seal, and Inspect
Allow the grouted floor to cure undisturbed for at least 24 hours before light foot traffic and 72 hours before full use. Once fully cured, apply a penetrating grout sealer to cement-based grout — this is especially important in kitchens, bathrooms, and outdoor areas where moisture and oil can stain unsealed grout within weeks. Apply the sealer with a small brush along each joint, wipe any excess off the tile faces immediately, and allow to dry per the manufacturer's instructions. Inspect all joints for pinholes or low spots; if found, dampen and fill with fresh grout rather than trying to force sealer into the gap.
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FAQ
- How long should I wait before walking on a freshly grouted floor?
- Wait at least 24 hours before light foot traffic and a full 72 hours before placing furniture or heavy loads. In hot and dry conditions common in Greece, the surface may feel dry sooner, but the grout continues to cure internally and can crack if stressed too early.
- Why is my grout cracking along the joints?
- The most common causes are: tile adhesive that had not fully cured before grouting; grout mixed with too much water; joints that were filled over a flexible or moving substrate without using a flexible polymer-modified grout; or movement joints (expansion gaps) that were incorrectly filled with rigid grout instead of flexible silicone sealant. Movement joints around the perimeter of the floor and at structural breaks must always be finished with a colour-matched silicone or polyurethane joint sealant, not cement grout.
- Do I need to seal grout on all floor types?
- Cement-based grout — sanded or unsanded — is porous and should always be sealed, especially in wet rooms, kitchens, and outdoor terraces. Epoxy grout is non-porous and does not require sealing. Even with sealer, plan to reseal cement grout every 1-2 years in high-traffic or high-moisture areas.