Most of the quotes on India market for Venetian plaster sit around ₹150 a square foot with the labour in it, and a few go up to ₹250. Then you open the price page of a Venetian plaster specialist in India and the lime material on its own, no labour at all, is ₹140 to ₹220. Both prices can’t be for the same thing. At ₹150 for the full job, the mistri is most likely bringing an acrylic texture paint and calling it Venetian.
Before anyone starts, ask for the product name and look at the tub for the word lime.
Venetian Plaster Is Slaked Lime And Marble Dust
Slaked lime, marble dust and some color, that is all it is. The mistri lays it on in thin coats with a steel trowel and keeps rubbing it with the trowel till it shines, and if he rubs it less you get marmorino, the matte one.
We have had lime here for a long time, the plaster in the Ellora caves goes back to the 6th century AD, and old builders put gur, gugal and methi in it to make the wall throw off water.
On the wall, lime keeps taking carbon dioxide out of the air and slowly turns back into limestone (Vasari’s explainer has the chemistry if you want it), which is why a lime wall gets harder every year instead of weaker. Acrylic can’t do that. It seals the wall as well, and a sealed wall in our barsaat is how seelan gets started.
In Ahmedabad The Unpainted Lime House Stayed Coolest
CEPT University sent a team round 45 lime plastered rooms in Ahmedabad in the dry months of 2019 and 2020, most of them in the old Pol houses, where families have lived behind thick walls for a few hundred years and still put their washing out on the otla. One of the houses on their list was the RSR residence, a bungalow Abhikram Architects finished in marmorino and never painted, and they checked 13 rooms in it.
If you read the paper you can see the heat result clearly. They called a room hot when its walls were giving off more heat than the outside, and in March it went like this:
- Plastic paint over the plaster, hot 30% of the time.
- Limewash in the Pol houses, 18.5%.
- The unpainted RSR walls, 8.6%.
Lime mortar holds about 3 times the moisture cement mortar does, and that makes the room swing less with the weather, the wall soaks damp up on a sticky afternoon and gives it back once the air dries.
Mold Grew Where Plastic Paint Or Clutter Trapped The Damp
One living room in the RSR house did have mold on it. There was a water pipeline running inside that wall and a pool right outside it.
In the other houses the pattern was plain enough. Where plastic paint sat over the lime the damp stayed in, the same in rooms where the windows were kept shut or the cupboards were pushed right up against the wall, and the store rooms stuffed with things had mold on all four walls. Airy rooms with some sun coming in were mostly clean.
Never put plastic emulsion over a lime wall.
July to October is when these walls get tested. Their computer model of one Pol room kept the wall surface above 68% humidity all through those months, and lime samples sitting at about 95% humidity grew mold in 3 weeks. Mind it, lime helps with seelan, it does not make it go away, and you still have to throw the windows open whenever the rain stops for a day.
A Venetian Plaster Feature Wall Costs ₹26,000 To ₹91,000
The paper says nothing about what RSR spent on its walls. For prices, Paint Art’s price breaks it down like this:
- Basic material ₹140 to ₹220 a sq ft, premium ₹180 to ₹380.
- Labour ₹80 to ₹280 for a plain finish, ₹180 to ₹380 for complex designs.
- Gold leaf, if you want it, ₹2,500 to ₹3,000 for every 100 sq ft on top.
Most homes do it on one wall anyway, behind the TV or the bed, because you pay by the square foot. A 10 by 12 wall comes to 120 square feet, which works out to roughly ₹26,400 at the cheap end and ₹91,200 at the top, and the gap is mostly the mistri’s hours, since a high shine means more coats and more rubbing.
I like it with plain furniture in front. A printed sofa against shiny plaster is too much going on, and the living room ideas on this site keep it to one textured wall for the same reason.
Bathrooms And Kitchens
Fine on bathroom walls away from the water if you wax it near the basin. Not inside the shower. In the kitchen the oil gets into it behind the stove, and a glass splashback does that spot better.
Check The Wall For Leaks Before The Mistri Starts
Underneath, it wants cement plaster that has dried out properly. If there is any leakage, from a pipe or the terrace slab, get it fixed first, because lime will help a wall dry but it can’t stop water coming in, and that one RSR room shows it. Old plastic paint has to come off, or the mistri should use the primer written on the lime product, since lime won’t hold on a sealed vinyl wall. The color you can choose after, from the home decor side.