RenderHydraulic lime (NHL)
Enduit à la chaux
A material rather than a colour: one to three millimetres trowelled on, giving the wall a relief and a depth no paint imitates.
A lime-plastered wall on Tinos at sunset: the raking light picks out every pass of the hand left in the material.
Photo Jules Verne Times Two · CC BY-SA 4.0 · Wikimedia Commons
At a glance
- Water
- Steam only
- Outside
- Exposed
- Floor
- Walls only
- Upkeep
- Almost none
- Vapour
- Vapour-open
What it is made of
Lime and sand batched by volume, coloured right through with pigments — and laid in three passes of decreasing grain: a very liquid keying coat (1:1 to 1:1.5, sand 0/4), a body coat that trues the wall (1:2.5 to 1:3, sand 0/2), a lean finish coat (1:3 to 1:4, sand 0/1). Air lime CL indoors, hydraulic NHL as soon as damp is involved.
Application
The support
Stable masonry, cleared of anything loose. Rake out the joints and soak the wall the day before and at application — dry masonry drinks the render’s water and burns it.
Tools
Trowel, float, finishing trowel, straightedge, mixer, sprayer.
Steps
- 1Scratch coat (gobetis): a very wet coat thrown on to key into the support.
- 2Body coat: the thick coat, ruled flat with the straightedge.
- 3Finish coat: leaner and finer, floated, smoothed or scraped for the look you want.
- 4Mist it for several days and protect from sun, wind and frost.
Drying
Several days between coats, sometimes one to two weeks outdoors; the lime keeps hardening for months.
The trade’s general sequence, at about 20 °C. Where a producer publishes its own data sheet, that sheet wins.
Price
8 products from 3 producers
Cheapest pot
18.33 €
sac de 25kg
Per kilo, from
0.73 €
Per m², from
not published
| Product | From | €/kg · €/L | €/m² |
|---|---|---|---|
| Sofolith — enduit extérieur à la chauxSociété des Ocres de France | 18.33 € | 0.73 €/kg | — |
| Sofodor — enduit décoratif à la chauxSociété des Ocres de France | 50.00 € | 2.50 €/kg | — |
| Enduit poussière d'étoileBiologement | 70.80 € | 10.45 €/kg | — |
| Enduit chaux fineBiologement | 104.40 € | — | — |
| Enduit de Chaux Naturelle - MarmolaktMercadier | 162.80 € | 10.85 €/kg | — |
| Enduit de Chaux Naturelle - Marbrex LMercadier | — | — | — |
| Enduit de Chaux Naturelle - Marbrex RMercadier | — | — | — |
| Enduit de Chaux Naturelle - Minéral 000Mercadier | — | — | — |
Material prices incl. VAT as published by this catalogue’s producers, samples excluded. Labour is never included, and a price per m² only exists where the producer publishes a coverage.
Upkeep
Next to nothing: it ages well, repairs in patches, and lasts fifty years on a facade in the right NHL.
- Demands · Almost none
- Vapour-open
On a real wall
A lime render halfway across a rubble wall: bare masonry on the right, the material that has taken over on the left.
Photo Berrucomons · CC BY-SA 3.0 · Wikimedia Commons