Is the concrete surface ugly, gravelly, or full of holes before painting? Structural repair mortar is strong but hard to smooth and expensive on large surfaces. Geolite Silt is a lightweight, high-yield smoothing mortar: creamy spreadable, smooth surface from 2–50 mm. Paintable after 4 hours. This is Kerakoll Geolite Silt.

Geolite is the first geo-mortar for repairing damaged reinforced concrete: Kerakoll geo-binder, with near-zero shrinkage and high chemical resistance.

• Smoothing gravel nests, holes, uneven fair-faced concrete: lightweight geo-mortar — creamy spreadable, smooth, paintable surface from 2–50 mm
• Large surface economically: high yield, ≈ 12 kg/m²/cm — less material than structural mortar
• Crack-prone, moving substrate: low modulus of elasticity (13 GPa) — moves with the concrete, R2 class
• Fast further processing: semi-fast, ≈ 30 minutes setting, paintable after 4 hours — work progresses the same day
• Repair of junctions between new and old concrete, cornices, window sills: fills and levels surface defects
• Does not drip even overhead or vertically: thixotropic — works on ceilings and beams
• Breathable, non-combustible surface: A1 fire resistance, vapor permeable (Class I) — mineral, geo-binder based

What is it suitable for?

Substrates: Healthy, load-bearing concrete and reinforced concrete — indoors and outdoors. Worn, uneven, gravel-nested concrete surfaces. Concrete repaired with the Geolite family’s geo-mortars before painting.

Usage: Local and general protective smoothing of concrete surfaces; non-structural restoration of worn concrete parts; filling and leveling surface defects (junctions of new and old concrete, gravel nests, holes); repair of decorative elements — cornices, window sills, parapets. On horizontal concrete after Primer Uni.

Not suitable for: load-bearing, structural repairs (use R4 Geolite / 10 / 40 for that); contaminated, loose, crumbling, or dusty substrates; gypsum, metal, wood; surfaces below +5 °C, above +40 °C, or frozen.

The Geolite concrete repair system

Structural repair or smoothing needed?

• Load-bearing, structural repair (R4): Geolite / Geolite 40 / Geolite 10
• Smooth, aesthetic, non-structural surface (R2): Geolite Silt — this product, highly economical
• Carbonation-resistant finish: Geolite MicroSilicato — breathable paint

Frequently asked questions

How to create a smooth, paintable surface on rough, gravelly concrete?
Lightweight, non-structural smoothing geo-mortar that is creamy and paintable after 4 hours. Geolite Silt fills gravel nests, holes, and unevenness from 2–50 mm. First repair structural defects with R4 mortar.

What is the difference between structural and smoothing repair mortar?
Structural mortar (R4, e.g. Geolite) restores load-bearing capacity; smoothing mortar (R2, Geolite Silt) provides an aesthetic, smooth surface. Silt is lighter, more economical, and easier to apply but not load-bearing. They are often used consecutively.

What does the R2 class mean?
R2 is the EN 1504-3 non-structural repair mortar class. It has lower strength (28 days > 15 N/mm²), suitable for surface, aesthetic repairs — not for load-bearing structures. For load-bearing, R4 class Geolite is required.

How many m² does a 15 kg bag cover?
Material requirement ≈ 12 kg/m² per centimeter — low due to the lightweight composition. For a 10 mm layer, a 15 kg bag covers ≈ 1.25 m², for 5 mm ≈ 2.5 m². Therefore economical for large surfaces.

When can the smoothed surface be painted?
Geolite Silt can be painted after 4 hours. For breathable, carbonation-resistant protection, Geolite MicroSilicato paint can be applied. The surface must be dry and stable.

How thick can it be applied?
Between 2 and 50 mm in a single layer. For thin smoothing from 2 mm, for deeper defect filling up to 50 mm. For thicker, load-bearing repairs, use structural Geolite.

Is a primer needed under the smoothing mortar?
For horizontal concrete surfaces, Primer Uni substrate primer is recommended for proper absorption. The substrate must be clean, solid, and rough. Wet thoroughly before application.

When should I NOT use this smoothing mortar?
Do not use for load-bearing, structural repairs — for that, use R4 Geolite, 10, or 40. Do not apply on dirty, loose, dusty substrates, gypsum, metal, wood, or frozen surfaces.

Can I apply it myself?
Yes, smoothing can be done by a skilled hand: cleaning, wetting, applying with a trowel, then smoothing with a sponge float. However, large surfaces, facades, or structural repairs require expertise. We also undertake complete execution.