Installing and grouting glass mosaic: a professional guide
Workshop expertise · Glass mosaic
Installing and grouting glass mosaic –
the complete process in 14 steps
From the first pass of the notched trowel to the final polish: how to bond glass mosaic, remove the paper, grout with epoxy resin and clean away all haze. Written for people who take the work into their own hands, and for tradespeople who leave nothing to chance.
Glass mosaic is the most revealing surface in the bathroom. It hides nothing. Every irregularity in the substrate shows, every trace of adhesive shines through the glass, and every surface haze takes away exactly what you bought the mosaic for: depth. The good news is that this guide contains no individually difficult technique. What matters is following the right sequence and understanding a few working windows.
This guide describes the method we recommend at Tiamont for SICIS® glass mosaics combined with the Litokol system: bonding with PowerGel® Pro Max, grouting with Starlike® Crystal or Starlike® Pro, and cleaning with Starlike® Care. Both manufacturers come from Italy, the systems work together, and this exact combination is otherwise not fully described in the German-speaking market.
The short version if you are on site right now:
Bond glass mosaic to a level, sound and dry substrate with a white two-component epoxy adhesive, using a 3.5 mm notched trowel and working on only about one square metre at a time. After 24 hours, wet and peel off the paper on paper-faced mosaic, then wash the surface clean with water. Only when the joints are completely dry should you apply epoxy grout, working it diagonally into the joints and cleaning immediately while fresh: first with white felt in circular movements, then with a sponge. Carry out subsequent cleaning with Starlike® Care after 24 hours, no later than 48 hours.
Why glass mosaic is unlike any tile
A porcelain tile is a closed, opaque slab. No one sees what happens underneath. Glass is the opposite: it is a window. Light passes through the tessera, strikes the adhesive beneath and returns to the eye. That is why glass mosaic follows three distinctive rules.
The adhesive is part of the appearance
Grey adhesive under a light glass tessera makes it look grey. Visibly, not just slightly. Glass mosaic therefore follows a colour rule you only need to understand once. PowerGel® Pro Max comes in two colours, both technically identical: the same two-component epoxy adhesive, the same classification combining bonding and waterproofing in one system, watertight and suitable for swimming pools as well as showers. The difference is entirely in what you see afterwards.
| Your surface | Adhesive colour | Why |
|---|---|---|
| Translucent glass, light tones, white, mother-of-pearl, gold and silver effects | Ultra Bianco (white) | Light passes through the tessera to the adhesive and returns. Any grey surface beneath tones down the colour and makes it dull. |
| Dark glass coloured throughout, opaque mosaics, anthracite, brown and blue tones | Grigio (grey) | No light passes through. Grey can even create a calmer effect here: variations in the adhesive application that would appear cloudy beneath light glass disappear. |
| Natural stone, marble mosaic, porcelain tiles and ceramic mosaic | Grigio (grey) | Opaque coverings. Here the bond matters, rather than the colour, except with light, thin marble that may be translucent. In that case, use white. |
White is never the wrong choice. Grey can be, irreversibly, because you only see the adhesive once the mosaic is laid. If you are unsure whether your tessera transmits light, hold it against a lamp. If light passes through, choose Ultra Bianco. If it stays dark, you save nothing but gain a calmer surface with Grigio.
The grout plays a central role
With 2.3 cm mosaic tesserae, one square metre contains more than eighty metres of joints. Grout therefore has a substantial role in the overall design and, with cementitious grout, is also the weak point: it absorbs water and colour, and becomes stained. Epoxy does not absorb. It is virtually non-porous, acid-resistant and colour-stable. In a shower used every day, it is therefore worth comparing the water absorption and care properties of the specific grout.
Cleaning is part of installation, rather than tidying up afterwards
This is where most DIY installers struggle. With cementitious grout, you wipe after the mortar has started to set. With epoxy, cleaning begins while the material is fresh, immediately after working it into the joints. If you wait until the mixture hardens, you will be grinding rather than cleaning.
With epoxy, grouting and cleaning are one single operation. You do not stop grouting and then begin cleaning. Grout a section, clean it, and only then start the next section.
Materials and tools at a glance
Six products and four tools handle the entire job: two grouts, two cleaners and two adhesives. Everything else is an accessory. Print just this page and take it to the site to have everything together.
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Grout · Steps 7–8Starlike® Crystal
Translucent and neutral. The grout recedes visually while the glass retains its depth. Joints up to 3 mm.
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Grout · Steps 7–8Starlike® Pro
75 designer colours, joints from 1 to 20 mm. When the grout should add colour.
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Cleaner · FloorsStarlike® Care
Subsequent cleaning for horizontal surfaces. Removes the final haze. 4 litres for approximately 60 m².
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Cleaner · WallsStarlike® Wall Care Gel
The same principle in gel form: stays on the wall instead of running down. 3 litres for approximately 35 m².
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Adhesive · Light glassPowerGel® Pro Max Ultra Bianco
Pure white. Essential for translucent and light glass. Bonds and waterproofs in one operation; 10 kg for approximately 6.7 m².
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Adhesive · Dark surfacesPowerGel® Pro Max Grigio
The grey version of the same system. For dark, opaque mosaics, natural stone and porcelain tiles.
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The four tools and what each one does
There is no all-purpose tool for epoxy. Each of the four tools has a specific task and does it better than an improvised alternative from a DIY shop.
| Tool | When | Purpose |
|---|---|---|
| SoftGrip notched trowel 3.5 mm (sometimes 2 mm) |
Step 3 | Applies the contact layer and combs the adhesive. The notch size determines how much adhesive lies beneath the tessera: too much squeezes into the joint; too little fails to support it. |
| Spachtel Pro Starlike® Rubber grout float |
Steps 4 and 8 | Presses in the mosaic sheet and later pushes grout into the joints. Soft enough not to scratch glass. |
| Feltro Pro Starlike® White felt |
Step 10 | The most important technique in this guide. Emulsifies excess epoxy in circular movements and loosens it from the glass surface. |
| Spugna Pro Starlike® Sponge |
Steps 11 and 14 | Removes the loosened emulsion and shapes a smooth joint without washing it out. |
We supply original Litokol tools on request: Spachtel Pro, Feltro Pro and Spugna Pro, as well as the Starlike Tools Box with one rubber float, four felts and two sponges. Send us a brief note about your planned surface and we will assemble the right set. Get advice
Steps 1–4: substrate, adhesive and setting mosaic
This first stage determines the appearance. Everything that goes wrong here will later show through the glass, when it can no longer be corrected.
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01
Preparation
Prepare the substrate
The substrate must be level, sound, clean, and free from dust and grease. Mosaic demands a stricter definition of “level” than large tiles: a depression hidden beneath a 60 cm tile becomes a visible wave in mosaic because mosaic follows the surface.
In wet areas, waterproofing must be in place. PowerGel® Pro Max can provide this itself: first apply a smooth layer at least 1 mm thick and allow it to cure for 12 to 24 hours. Only then apply the bonding layer.
The most common mistake of allDo not work on a substrate that is still damp or on waterproofing applied only “a few hours” ago. With epoxy, there is no subsequent drying beneath the tessera: trapped moisture stays there.
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02
Mixing
Mix PowerGel® Pro Max
Squeeze the entire component B sachet completely into component A. Completely means leaving nothing behind. A two-component resin only cures at the correct mixing ratio: if some stays in the sachet, the mixture remains soft at that point.
Mix with an electric mixer at approximately 300 revolutions per minute until creamy, smooth and free of lumps. Then scrape the sides and base of the bucket with a spatula and mix briefly again. Unmixed material collects there and may otherwise create a soft patch beneath the mosaic.
Why mix slowly?High speeds introduce air. Air bubbles in the adhesive appear as light spots beneath glass. 300 rpm is slow enough to keep air out and fast enough to mix uniformly.
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03
Application
Apply the adhesive: smooth first, then comb
Two passes, not one. First use the smooth side of the SoftGrip trowel to apply a thin contact layer, pressing firmly: this creates the actual bond to the substrate. Then comb with the notched side.
SICIS glass mosaic generally requires a 3.5 mm notch; some collections specify 2 mm. If in doubt, check the collection's data sheet or ask us.
Only one square metre at a timeNever prepare more than approximately 1 m². Epoxy adhesive forms a skin when exposed to air. If mosaic is placed on an area that has already started to set, it will no longer bond correctly, and you only discover this when tesserae come loose.
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04
Setting
Set the mosaic and tap it into place
Place the mosaic sheet into the fresh adhesive and press evenly with the rubber float: professionals call this “tapping”. Tap across the surface rather than sliding it. Sliding distorts the sheet and makes the joints uneven.
Watch two things: no air bubbles and complete coverage of the back. At the same time, the adhesive must not squeeze up into the joints, where space is needed for grout later. Remove excess immediately while fresh. Hardened epoxy can only be removed mechanically.
Steps 5–6: removing paper and drying joints
Many SICIS mosaics are paper-faced: the tesserae are attached to paper on their front face to hold the sheet together during installation. This paper must be removed after bonding, and the timing is more delicate than it appears.
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05
Only for paper-faced mosaic
Remove the paper
Wait approximately 24 hours for the adhesive to cure. Then thoroughly wet the paper with a damp sponge, wait a few minutes and only then peel it off.
Peel slowly, diagonally and close along the wall, rather than pulling forwards away from it. Pulling the paper straight away from the surface can dislodge individual tesserae. SICIS specifies water for this step, without expressly specifying warm water.
For first-time installersImagine removing a plaster: pulling it flat along the skin is gentler than pulling straight upwards. Mosaic follows the same principle.
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06
Intermediate step
Clean the surface and let the joints dry
Completely remove paper-adhesive residue with clean water. Paper adhesive is water-soluble and harmless provided it is not trapped beneath the grout.
Now patience can save real money: the joints must be completely dry and free of adhesive residue before grouting. Residual moisture causes discolouration and joints that fail to cure throughout.
Step 7: mixing grout correctly
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07
Starlike® Crystal or Pro
Mixing follows the same principle as the adhesive
Again, squeeze all of component B into A and mix at approximately 300 rpm until smooth and uniform. Scrape the sides and base, then mix briefly again. Those twenty seconds around the bucket edge can make the difference between uniformly hard joints and isolated sticky spots.
The clock starts when the two components meet. Under standard conditions, Starlike has a working time of more than 90 minutes. The next chapter explains what this means in practice: it is the most important chapter in the guide.
The chapter that determines the result
The 90 minutes: time is a tool when working with epoxy
Cementitious mortar tolerates breaks. You can leave the bucket, take a call and continue. Epoxy does not pause. The mixture starts reacting the moment you stir in the second component, and it does not stop. The times in the data sheet apply to defined reference conditions. They do not guarantee the same working window on every site. Follow the current product information; heat and batch size can shorten the practical working time.
What shortens the working time
- Heat. This is by far the biggest factor. Every degree above room temperature accelerates the reaction. In a bathroom with underfloor heating running, on a summer day with sunlight on the façade or in a building shell with a dehumidifier, the practical working window can become considerably shorter.
- The mixture itself. A full bucket retains reaction heat. The larger the continuous quantity, the faster it warms and sets.
- Direct sunlight on the surface. The tile temperature matters rather than the air temperature. A sunlit wall is significantly warmer than the room.
- Mixing too long at high speed. Friction generates heat in the bucket before the mixture even reaches the wall.
When to work
Grout large, exposed surfaces in the early morning or late afternoon, never in midday heat or with sunlight on the surface. Indoors, switch off underfloor heating at least a day beforehand and turn down nearby radiators. The ideal range is approximately 18 to 23 °C: comfortable for you and calmer for the resin.
How large can a section be?
Here is the most important figure in this guide: work in sections of approximately 1 to 2 m². Grout, clean immediately, then move to the next section. A section should be fully completed in around 15 minutes, from applying the grout to the last sponge pass.
A 5 kg bucket covers roughly 4 to 7 m² of fine glass mosaic, depending on tessera size and joint width. That gives approximately three to five such sections per bucket. Calculate this before mixing, and prefer two smaller batches to one large batch in warm conditions.
Water, sponges and felts: what must be ready
Going to fetch water halfway through cleaning means losing the working window. Before the first operation, have the following ready:
- Two buckets of clean water One for rinsing tools, one for the final pass
- A third bucket in reserve For changing water without interruption
- At least 4 white felts Feltro Pro Starlike®, one per section
- At least 2 sponges Spugna Pro Starlike®, plus one in reserve
- A rubber grout float Spachtel Pro Starlike®
- Clean, dry cotton cloths For drying afterwards
- Nitrile gloves and safety goggles Epoxy resin irritates skin and eyes
A rule of thumb for changing water: once the rinse-bucket water becomes milky, it is spent. Milky water carries the loosened epoxy back onto the surface, creating exactly the haze you will struggle to polish away the next day.
The data-sheet statement often misunderstood: “Washable for 80 minutes” is a technical laboratory test value. It is not a recommendation to wait 80 minutes. Always clean immediately while the material is fresh.
Step 8: filling the joints
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08
Grouting
Fill completely and remove excess diagonally
Fill the joints completely with Spachtel Pro Starlike®. Completely means to the bottom, without voids. Press the mixture into the joints rather than just passing over them.
Move the rubber float diagonally to the joints. Working parallel pulls out the material you have just applied. Diagonally, the float edge passes over the joint rather than into it. Remove excess material in the same movement and return it to the bucket.
An explanation for beginnersImagine spreading butter over a waffle iron: working across the recesses leaves butter in them. Working lengthways into them pulls it out again. That is how to hold the float.
Steps 9–11: the three cleaning passes
Now comes the part that turns a well-grouted surface into a beautiful one. Make three passes in this order, without a break between them.
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09
Immediately
Pre-clean with water
Do not wait for the epoxy to harden: cleaning starts while it is fresh. Moisten the surface with clean water. Here water is the medium in which the excess resin will be loosened, rather than a cleaning agent.
Do not flood the surface. An evenly damp surface is enough; standing water runs into the fresh joints and washes them out.
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10
The decisive technique
Work in circles with white felt
Moisten Feltro Pro Starlike® and work the surface in circular movements. This emulsifies excess epoxy, combining it with water to form a milky emulsion, and loosens it from the mosaic surface.
Work in circles rather than straight strokes. Circular movement works evenly across the joint from all sides and leaves it intact. A straight stroke pulls on one side and pushes on the other.
How to tell it is workingA whitish, slightly streaky layer forms beneath the felt. This is intentional: it is your epoxy haze in loosened form, before it can set. The next step removes precisely this layer.
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11
Remove the emulsion and shape the joints
Follow with the sponge
Wipe clean again with a damp Spugna Pro Starlike®. The joint should become smooth and compact without grout being washed out: the sponge shapes the joint rather than emptying it. Keep it damp rather than wet, and use little pressure.
Two water buckets are ideal: one to rinse the sponge and one with clean water for the final pass. Always make the last pass over an area with clean water and a wrung-out sponge.
Keep goingOnce this section is clean, continue immediately with the next square metre: grout, felt, sponge. Do not grout the whole wall before cleaning. This one rule separates successful glass mosaic from a surface that later needs grinding.
Steps 12–14: curing, Care and finishing
The surface is grouted and clean. What follows turns “clean” into “radiant”, within a working window you should not miss.
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12
The next day
Allow 24 hours to cure
After approximately 24 hours, any remaining epoxy haze can be removed selectively. Litokol recommends this subsequent cleaning between 24 hours and no later than 48 hours after grouting.
The longer the epoxy film cures, the harder it may be to remove. Beyond the intended subsequent-cleaning window, stronger specialist cleaners or mechanical methods may be needed, depending on the product and surface; damage is possible. Follow the manufacturer's instructions and check material compatibility.
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13
Subsequent cleaning
Apply Starlike® Care or Wall Care
Use Starlike® Care for floors and Starlike® Wall Care Gel for walls: the gel stays on the vertical surface rather than running down.
Apply undiluted and spread with white Feltro Pro Starlike®. Leave for 10 to 15 minutes; during this time you can work the area again in circles with the felt. Contact time is what makes the cleaner work; scrubbing does not replace it.
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14
Finishing
Final wash and drying
Remove the cleaning solution with Spugna Pro Starlike®, rinse thoroughly with fresh, clean water and dry with a clean, dry cloth.
The final instruction is also the one most often overlooked: do not allow wash water or cleaner to dry on the surface. Anything left to dry creates the very mark you have just removed. Wiping dry belongs to the operation, not the following week.
The installation and subsequent-cleaning schedule
Glass mosaic is not a weekend project you start on Saturday afternoon and finish that evening. Waiting times are inherent to the material. Plan them and work calmly; skip them and do the work twice.
| When | What happens | Why the time is needed |
|---|---|---|
| Day 0 · Preparation | Apply PowerGel® Pro Max waterproofing if none is already present | 12 to 24 hours of curing before bonding over it |
| Day 1 · Morning | Steps 1–4: check the substrate, mix adhesive, bond one square metre at a time and tap into place | The adhesive forms a skin in approximately 20 minutes, so work in small areas |
| Day 2 · Morning | Steps 5–6: wet and peel off the paper, clean the surface with water | Approximately 24 hours after bonding; earlier removal can pull out tesserae |
| Day 2 · Afternoon | Let the joints dry | Residual moisture causes discolouration and joints that fail to cure throughout |
| Day 3 · Early morning | Steps 7–11: mix, grout in sections and clean immediately | A cooler time of day noticeably extends the working time |
| Day 4 · After 24 hours | Steps 12–14: Starlike® Care or Wall Care, rinse with clean water and dry | The subsequent-cleaning window closes no later than 48 hours |
Allow three to four days between the first pass of the notched trowel and the finished surface being ready for foot traffic. The actual work on a shower splashback of approximately 5 m² takes around six to eight hours; the remainder is waiting.
Calculate quantities correctly before ordering
Few things are more frustrating than finding the bucket empty halfway across a surface. A second bucket from the same batch is often no longer available, and batch differences show in coloured joints. Calculate beforehand, allowing generously.
Grout consumption depends on tessera size
The smaller the tessera, the more metres of joints per square metre. A 2 × 2 cm mosaic has around twice as much jointing as a 5 × 5 cm mosaic. The following figures are practical guidelines for a joint width of 2 mm and a tessera thickness of 4 mm:
| Tessera size | Consumption per m² | A 5 kg bucket covers |
|---|---|---|
| 1.5 × 1.5 cm | Approximately 1.1 kg | Approximately 4.5 m² |
| 2.0 × 2.0 cm | Approximately 0.9 kg | Approximately 5.5 m² |
| 2.3 × 2.3 cm | Approximately 0.8 kg | Approximately 6 m² |
| 3.0 × 3.0 cm | Approximately 0.65 kg | Approximately 7.5 m² |
| 5.0 × 5.0 cm | Approximately 0.45 kg | Approximately 11 m² |
Adhesive: a simple rule of thumb
With a 3.5 mm notch, consumption is approximately 1.5 kg per m². A 10 kg pack of PowerGel® Pro Max Ultra Bianco therefore covers approximately 6.7 m². If the adhesive also provides waterproofing, the 1 mm layer requires an additional approximately 1.6 kg per m², reducing coverage of the same pack to just over 3 m² for the complete build-up.
Uneven substrates, cuts, corners and connections use up material. Add ten percent to every calculated quantity, and always order coloured grout in one delivery to ensure the same batch. Tell us your area and tessera size and we will calculate it for you free of charge: request a quantity calculation.
Shopping list
One bucket of Starlike and everything that goes with it
You have a 5 kg bucket of Starlike® Crystal or Starlike® Pro in your basket. What else do you need to start on Saturday morning? This list covers a typical area of 4 to 7 m², approximately what one bucket handles with fine glass mosaic.
Material
- Starlike® Crystal or Pro, 5 kg 1 bucket · 4–7 m²
- PowerGel® Pro Max Ultra Bianco, 10 kg 1 pack · Approximately 6.7 m²
- Starlike® Care (floor) or Wall Care Gel (wall) 1 pack
Tool
- SoftGrip notched trowel, 3.5 mm 1 tool
- Spachtel Pro Starlike® – rubber grout float 1 tool
- Feltro Pro Starlike® – white felts 4 pieces
- Spugna Pro Starlike® – sponges 2–3 pieces
- Electric mixer, adjustable to approximately 300 rpm 1 tool
- Spirit level and rubber mallet 1 of each
Consumables and protection
- Water buckets 3 buckets, 10–12 litres
- Clean cotton cloths 4–6 pieces
- Nitrile gloves 1 pack
- Safety goggles 1 pair
- Protective sheeting and masking tape As needed
Litokol's current Tools Box already contains 1 rubber float, 4 felts and 2 sponges, exactly the equipment for one bucket. We supply the box and individual tools on request. A brief message is enough for us to add the right set to your order.
Crystal or Pro: which grout suits your mosaic?
Both are gel-based epoxy grouts by Litokol, and both are waterproof and acid-resistant. The difference lies in joint width and appearance.
| Starlike® Crystal | Starlike® Pro | |
|---|---|---|
| Joint width | 0 to 3 mm | 1 to 20 mm |
| Appearance | Translucent and neutral: the joint recedes visually and the glass retains its depth | 75 opaque designer colours: the joint becomes a design element |
| Ideal for | Fine SICIS glass mosaic joints, translucent and shimmering collections | Coloured joint patterns, mixed surfaces with mosaic and larger formats |
| Pack size | 5 kg | 5 kg |
Typical SICIS glass mosaic joints are up to 3 mm wide. Starlike® Crystal suits them very well: light continues through the surface rather than breaking at a coloured joint. Choose Starlike® Pro when the grout should add colour or the joints are wider than 3 mm.
The seven most common mistakes
From our practical advisory experience: when someone calls us with a problem, it is almost always one of these seven.
- Bonding too large an area at once. The adhesive forms a skin and the mosaic no longer bonds correctly. Keep to one square metre.
- Grey adhesive beneath light glass. Irreversible. Bond glass mosaic with white adhesive.
- Adhesive squeezes into the joints. This leaves too little room for grout, making the joint shallow and prone to cracking. Remove excess immediately while fresh.
- Peeling paper too early or at too steep an angle. Individual tesserae come away with it. Wait 24 hours, wet thoroughly and peel close along the wall.
- Grouting before the joints are dry. This causes discolouration and joints that fail to cure properly throughout.
- Grouting the whole wall before cleaning. A classic cause of complete failure. Grouting and cleaning belong to the same operation, section by section.
- Continuing with milky water. The loosened epoxy returns to the surface. Change the water as soon as it becomes cloudy.
This guide describes the method for glass mosaic. To understand how epoxy behaves as a material more generally, on porcelain tiles, natural stone and large formats, read our article on applying epoxy grout.
Care: keeping the surface beautiful over time
The greatest advantage of epoxy joints appears in everyday use: they do not absorb. Limescale, soap and shampoo settle on the surface rather than penetrating it. Warm water and a soft cloth are therefore usually enough for maintenance.
What helps
- Use a squeegee after showering. A wall squeegee is the most effective care measure: no water, no limescale.
- Mild, pH-neutral cleaners. Entirely sufficient for weekly cleaning.
- Soft cloths and sponges. Glass is hard, but abrasive cleaners can still scratch it.
What causes damage
- Scouring cream and pan scourers. They permanently dull the glass surface, and dull glass loses the very depth for which glass mosaic is chosen.
- Repeated steam cleaning. Localised heat stresses every joint.
- Aggressive drain cleaners on the surface. Epoxy is acid-resistant, but the combination of heat and strong alkalis poses an unnecessary risk.
Annual deep cleaning with Starlike® Care or Wall Care Gel removes soap and limescale films that build up over the months. Afterwards, the surface looks as it did on day one because nothing has penetrated the joint.
Why order your materials from us?
Epoxy is a product that requires a considered choice. The combination must be right: adhesive, grout, cleaner and tools belong together. That is exactly what we do.
- Official Litokol specialist retailer. Original products, current batches and a complete grout collection, from adhesives and 75 grout colours to cleaners.
- Advice based on practical experience. We tell you which grout suits your tessera size and how much you need before you order.
- Tools on request. We add Spachtel Pro, Feltro Pro, Spugna Pro and the Starlike Tools Box to your order so nothing is missing.
- Matching mosaic from the same supplier. We stock SICIS® glass mosaics from Ravenna, so you receive advice on the mosaic and installation system together.
Frequently asked questions
Can I install glass mosaic myself without professional experience?
Yes, if you follow two rules: small sections and immediate cleaning after grouting. The techniques themselves are simple. Beginners struggle with the temptation to cover large areas at once rather than with the technique. Start with a small area such as a niche before tackling a complete shower wall.
Which adhesive is right for glass mosaic?
A white adhesive: with translucent glass this is essential, because the adhesive remains visible through the tessera. In wet areas and swimming pools, we recommend a two-component epoxy adhesive such as PowerGel® Pro Max Ultra Bianco, which can also provide waterproofing.
How long must glass mosaic adhesive dry before I can grout?
For paper-faced SICIS mosaic, remove the paper after approximately 24 hours. Clean the surface afterwards, and grout only when the joints are completely dry and free of adhesive residue. Allow another half to a full day as a precaution, depending on room conditions.
Why must epoxy be cleaned immediately?
Because epoxy cures chemically rather than drying. While fresh, excess material can be emulsified with water and felt and removed. Once cross-linking has progressed, this no longer works; chemical subsequent cleaning within 24 to 48 hours or mechanical work is then required.
What does “washable for 80 minutes” mean?
This is a technical laboratory test value describing how long the material can still be washed off under standard conditions. It does not recommend waiting that long. In practice, clean immediately after applying the grout.
How much area does a 5 kg bucket of Starlike cover?
Roughly 4 to 7 m² of fine glass mosaic, depending on tessera size, joint width and joint depth. The smaller the tessera, the more jointing per square metre and the greater the consumption. For an exact calculation, tell us the size and area and we will calculate it for you.
Can I install glass mosaic this way in a swimming pool?
Yes, this is one of the system's main applications. PowerGel® Pro Max is waterproof and can provide waterproofing; cured Starlike is virtually non-porous and resistant to chemicals. The curing periods before the first filling are important: they are specified in the data sheet and depend on temperature.
What should I do if haze remains?
Within 24 to 48 hours, treat it with Starlike® Care (floor) or Wall Care Gel (wall): apply undiluted, leave for 10 to 15 minutes, work in circles with white felt, remove, rinse with clean water and dry. If that window has passed, contact us: stronger specialist cleaners are available, but they require experienced handling.
Sources and data sheets
All application information in this article comes from the manufacturers' technical data sheets. Review dated September 2026.
- Litokol S.p.A. – PowerGel® Pro Max, product page with data sheets Substrate preparation, waterproofing application and mixing instructions
- Litokol S.p.A. – Starlike® Crystal, product page with data sheets Mixing, working time, joint width 0–3 mm and cleaning
- Litokol S.p.A. – Starlike® Pro, product and data-sheet page Joint width 1–20 mm, colour system and subsequent cleaning after 24–48 hours
- SICIS S.r.l. – Product Installation Manual (EN) Notch size, area size, tapping, paper removal and drying before grouting
- Litokol S.p.A. – Feltro Pro Starlike®, Spugna Pro Starlike®, Spatola Pro Starlike® Tool specifications and order of use
