Does cement plaster trap moisture in the wall? Moisture cannot dry out — paint flakes, corners mold. Biocalce Intonaco is pure NHL 3.5 lime — highly breathable (μ ≤ 6), releases moisture, naturally inhibits mold. For brick, tuff, stone, and mixed walls, exterior and interior. This is Kerakoll Biocalce Intonaco.
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Does cement plaster trap moisture: the wall breathes freely — pure NHL 3.5 lime, μ ≤ 6 water vapor diffusion, ≥ 40% porosity
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Corner or wall moldy: naturally inhibits mold — B+ and F+ rating, fungus- and bacteria-resistant (CSTB)
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Old, mixed masonry: one plaster for everything — hollow and solid brick, tuff, stone, mixed masonry, for exterior and interior
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Monument, adobe, old house: natural material matching the wall — only lime, pozzolan, quartz sand, and dolomite limestone, without cement
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Closed living space, poor indoor air quality: actively dilutes pollutants — IAQ Active certification, EC1 plus low VOC emissions
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System base: the Biocalce restoration system body plaster — on Rinzaffo base plaster, finished with fine plaster and breathable paint
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By hand and machine: easier application than traditional plaster — WTA-certified mix, can be applied with plastering machine
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Fire- and environmentally safe surface required: A1 fire resistance class — non-combustible, mineral-based, GreenBuilding Rating 5
| Type |
general plaster mortar, GP (EN 998-1) |
| Function |
breathable lime base plaster (body coat) for exterior and interior |
| Binder |
NHL 3.5 pure natural hydraulic lime |
| Water vapor diffusion (μ) |
≤ 6 — highly breathable |
| Compressive strength |
CS II (EN 998-1) |
| Max. layer thickness |
≈ 2 cm / layer |
| Material requirement |
≈ 13 kg/m²/cm |
| Storage |
≈ 12 months |
| Packaging |
25 kg bag |
What is it suitable for?
Substrates: Hollow and solid brick, tuff, stone, and mixed (load-bearing and infill) masonry. Monument and historic building restoration. Absorbent and non-absorbent walls (for the latter, first Rinzaffo base plaster). Cellular prefabricated panel — with special preparation (Biocalce Fondo, reinforcing mesh).
Spaces: Exterior and interior — facade, interior walls, living spaces where a healthy, breathable surface is the goal (Edilizia del Benessere).
Function in the system: Biocalce restoration system body plaster (2nd layer). Under it Rinzaffo adhesion promoter, then Biocalce fine plaster (Intonachino Fino or Granello), then breathable paint; for the finest, polished finish over the Fino Tipo “00”.
Not suitable for:
- On dirty, loose, dusty substrate — clean it first
- On old paint or existing leveling
- On surfaces covered with salt deposits — remove them first
- For high rising damp + strong salt load alone — there Zoccolatura salt-blocking plaster is the right choice
The Biocalce restoration system
Biocalce Intonaco is the body plaster of the system. The complete breathable build-up:
| Layer |
Product |
Role |
| 1. Base plaster |
Rinzaffo |
adhesion promoter on dense/non-absorbent substrate |
| 2. Body plaster |
Biocalce Intonaco — this product |
breathable plaster layer |
| 3. Fine plaster |
Intonachino Fino / Granello
|
smooth or grainy, paintable surface |
| 3b. Polished topcoat |
Tipo “00” — over the Fino |
finest, polished surface |
| 4. Surface |
breathable paint or decorative plaster |
final, breathable, colored surface |
Surface (4th layer): breathable paint — Biocalce Tinteggio, Silicato Puro Pittura, indoors Absolute Paint also, on facades Kerakover Silox Pittura; decorative plaster — Silicato Puro, Marmorino, Spatolato.
Which base plaster do you need?
- General body plaster, thicker build-up: Biocalce Intonaco (0–2.5 mm) — this product
- Smooth base, thin layer, new facade: Intonaco Fino (0–1.4 mm)
- Salty, rising damp: Zoccolatura salt-blocking plaster
- Energy saving, warm wall: Benesserebio thermal insulation
Frequently asked questions
Why doesn’t the wall breathe under cement plaster?
Cement plaster is dense and has high vapor diffusion resistance — it traps moisture inside the wall. That’s why paint flakes and corners get moldy. Breathable lime-based base plaster (e.g., Kerakoll Biocalce Intonaco) allows vapor to escape with a μ ≤ 6 value.
What is breathable plaster?
Breathable plaster allows water vapor to pass through, so the wall dries out and moisture does not get trapped. Pure lime-based plaster is porous (≥ 40%) and has low water vapor diffusion resistance (μ ≤ 6). Biocalce Intonaco is such a natural, eco-friendly lime plaster — without cement.
What kind of walls is lime plaster suitable for?
Suitable for hollow and solid bricks, tuff, stone, and mixed masonry — for both interior and exterior plastering. On solid or non-absorbent substrates, first apply Biocalce Rinzaffo base plaster. For damp, salt-affected walls, the complete Biocalce system (Rinzaffo + Zoccolatura) is the solution.
Is lime plaster good for moldy walls?
Yes, natural lime plaster inhibits mold on moldy walls — Biocalce Intonaco is B+ and F+ rated according to CSTB method. Its high breathability keeps the wall dry, so mold finds no wet surface.
What is needed over Biocalce Intonaco?
A finishing plaster and breathable paint go over the base plaster. For smooth surfaces, use Intonachino Fino, for grainier surfaces Granello; for the finest, polished finish, apply Tipo “00” over Fino. Use lime-based, breathable paint.
Which breathable base plaster is needed — Intonaco or Intonaco Fino?
The grain size and layer thickness matter. Intonaco is coarser (0–2.5 mm), a general base plaster for thicker builds. Intonaco Fino is finer (0–1.4 mm) — smooth base in thin layers, ideal for new facades and machine application.
What do GP, CS II, and μ ≤ 6 mean?
GP means general plaster mortar (EN 998-1). CS II is the 28-day compressive strength category. μ ≤ 6 is the water vapor diffusion resistance — the lower, the more breathable the plaster.
How many m² does a 25 kg bag cover?
Material requirement ≈ 13 kg/m² per centimeter. A 25 kg bag covers ≈ 1.9 m² at 1 cm thickness. Maximum ≈ 2 cm can be applied in one layer.
When should I NOT use it?
Do not apply on dirty, dusty, loose substrates, old paint, or leveling layers. Remove salt deposits first. For strong rising damp and salt load, use Zoccolatura salt-blocking plaster.
Can I apply it myself?
Yes, it can be applied by hand or machine, more easily than traditional plaster. However, repairing damp, salty walls requires expertise — we also carry out the complete Biocalce system.
