Planning to apply lime plaster or lime paint on gypsum or old paint? It won’t adhere, it flakes off. This lime primer provides an adhesive bridge and fills small irregularities. Fine-grained, bacteriostatic. This is the primer of the Biocalce lime decoration system.
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Lime decoration on gypsum, drywall, old paint: adheres — the CL 90-S lime primer provides an adhesive bridge, the lime layer does not flake off
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Part of the system: the primer of the Biocalce lime decoration system — under Biocalce Tinteggio lime paint and lime noble plasters
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Uneven, micro-cracked substrate: fills — outstanding filler effect, restores small irregularities, fine-grained surface
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Risk of blotchy painting: evens out absorbency — consistent shade under lime paint, no blotchiness
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Healthy indoor air: actively dilutes pollutants — IAQ ACTIVE, French A+ air quality
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Cleaner wall: antibacterial and antifungal effect (CSTB method) — less biological contamination
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Porous and breathable — allows the wall to breathe freely
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Primer, not finishing: the color and surface are provided by Biocalce Tinteggio lime paint or lime noble plaster
| Type |
Filler lime primer for lime decoration (indoor and outdoor) |
| Binder |
CL 90-S pure lime (EN 459-1) |
| Performance |
Filler
porous, breathable
IAQ ACTIVE |
| Material requirement |
≈ 0.15–0.3 l/m² per layer (1–2 layers)
14 l ≈ 25–45 m² |
| Packaging |
Bucket 14 l and 4 l |
| Storage |
≈ 12 months |
What is it suitable for?
Substrates: Indoor gypsum and drywall surfaces, surfaces painted with synthetic paint, porous surfaces with different absorbency, partially renovated surfaces with different materials. Where lime decoration needs an adhesive bridge and filling of small unevenness.
Spaces: Primarily for indoor lime decoration — interior walls and ceilings of residential buildings, historic interior spaces. Outdoors only limited use on porous mineral surfaces; not under lime smoothing plaster or cement (see Not suitable).
Function in the system: The filler primer of the Biocalce lime decoration system. It provides adhesion for lime paint and lime noble plasters, filling small irregularities.
Not suitable:
- As a standalone, finished surface (without lime paint or noble plaster) — this is a primer, not a decorative layer
- Outdoors before lime-based smoothing compounds or cement
- Indoors on synthetic paint if a silicate-based layer follows
- For walls exposed to capillary moisture — first a moisture-proof plaster (Biocalce Zoccolatura / Benesserebio) is required
The Biocalce lime system
Biocalce Fondo is needed when applying lime decoration to a substrate to which lime does not adhere by itself — gypsum, drywall, old paint. The structure:
| Layer |
Product |
Role |
| Substrate |
Gypsum, drywall, old synthetic paint, mixed/patched surface |
lime does not adhere by itself |
| Adhesive, filling primer |
Biocalce Fondo — this product |
adhesive bridge + filling + uniform moisture absorption |
| Lime surface |
Biocalce Tinteggio lime paint / Biocalce Marmorino / Biocalce Spatolato
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Breathable, colored lime decoration |
Fresh Biocalce lime plaster (Biocalce Intonaco → Biocalce Intonachino Fino) does not require Fondo — the lime surface adheres directly. Fondo is the adhesive bridge for non-lime, heavy substrates (gypsum, drywall, old paint).
Which lime primer is needed?
Frequently Asked Questions (FAQ)
Why doesn't lime paint or lime plaster adhere to gypsum?
Because gypsum and old paint do not provide an adhesive surface for lime. The filling lime primer creates an adhesive bridge, and the lime decoration adheres to it. Without it, the layer may peel off.
Which primer is needed under lime paint on drywall?
Filler or universal lime primer. Biocalce Fondo fills small irregularities and provides a fine-grained surface. For smooth substrates, Biocalce Fondo Universale is sufficient.
What is the difference between Fondo and Fondo Universale?
Biocalce Fondo is a filler: it fills microcracks, is fine-grained, and bacteriostatic. Biocalce Fondo Universale is a universal, thin bonding primer that does not change the appearance of the surface. Use Fondo on uneven substrates, Universale on smooth ones.
Is a topcoat needed over the lime primer?
Yes. Biocalce Fondo is a primer, not a finished surface. Lime paint Biocalce Tinteggio or a lime noble plaster is applied over it.
Can it be used outdoors?
Its main use is indoor lime decoration. Outdoors, it can only be used to a limited extent on porous mineral surfaces. It is not suitable under lime smoothing plaster or cement — a different system is required there.
How much primer is needed, how many m² does it cover?
Approximately 0.15–0.3 l/m² per coat, usually in 1–2 coats. A 14-liter container covers about 25–45 m². The exact amount depends on the substrate and number of coats.
Is lime or silicate primer needed?
It depends on the decorative surface. Lime primer is needed for lime painting or lime noble plaster (Biocalce Tinteggio, Biocalce Marmorino) — this product belongs to that system. For silicate painting (Biocalce Silicato Puro Pittura), silicate primer is required: Biocalce Silicato Consolidante + Biocalce Silicato Fondo.
When should I not use it?
Do not apply on walls with rising damp without pretreatment. Outdoors, do not apply under lime smoothing compound or cement, or under synthetic paint beneath a silicate layer — different preparation is required there.
Can it be purchased separately?
Yes. You can purchase it even if you already have the other system products, if you are preparing an existing surface, or if you have a small amount left from a project.
Can I apply it myself?
Yes — with a brush or roller, in 1–2 coats. Proper application of lime decoration requires practice. We also carry out the complete lime system installation.
