Material · Mineral · Finish
Lime Plaster
Slaked lime plaster · Roman plaster
A wall finish of slaked lime that cures by reabsorbing CO₂ and slowly turning back into limestone. It is vapor-open — walls absorb humidity spikes and release them — and its high-pH surface actively resists mold without biocides.
Why it matters
Most wall finishes are a paint film stretched over drywall; lime plaster is a wall that participates in the room. It buffers moisture swings the way wool buffers a bed, kills the mold conversation at the surface-chemistry level, and delivers the soft, mottled depth that flat paint imitates with faux finishes. For bathrooms, basements, and bedrooms, it is a functional upgrade wearing an aesthetic one.
Benefits
- Vapor-open: buffers room humidity instead of trapping it behind a film
- Surface pH around 12 — actively hostile to mold without added biocides
- Zero-VOC mineral chemistry with no acrylic binders
- Soft, luminous, variable surface that ages rather than peels
- Reabsorbs CO₂ while curing, partially offsetting its firing
Best applications
Rooms: Bathroom · Bedroom · Living · Whole home
Performance
Watch-outs
- "Lime paint" and limewash-look acrylics borrow the aesthetic without the chemistry — read the binder
- Needs a compatible vapor-open substrate; lime over plastic sheeting or glossy paint wastes the material
- Hairline cracking is normal and patchable, but unskilled application shows
- Skilled applicators are a real constraint outside major markets
What to verify
Finish, binder, sourcing, and installation conditions to confirm before specifying.
- That the product is true lime, not acrylic-modified "lime-look" paint
- Substrate compatibility and primer system — vapor-openness dies at a sealed base coat
- Applicator portfolio; this is a craft trade
- Pigment source if tinted
Certifications to look for
The labels that separate the real material from the marketing version.
Declare label
Full ingredient disclosure — confirms a pure lime mix versus acrylic-modified products
EN 459
European classification for building limes — the base-material spec
On Compound
Where this material shows up across the directory.
Sources
Information verified July 2026.