Lime Plaster and Traditional Finishes in India: Araish, Chettinad and Lime Wash

Use lime plaster on old buildings laid in lime mortar, on interior walls, and for polished traditional finishes such as araish or Chettinad plaster. On new exterior walls that take heavy rain, India's lime plaster code says lime is not suitable, so cement plaster stays the default. Expect lime to cost about three times as much: Karnataka's 2023-24 Schedule of Rates gives ₹999 per m² for two-coat lime plaster against ₹333 for cement.

The lime you buy: the six classes in IS 712

IS 712:1984, the building lime specification, sorts lime into six classes; the uses are only suggestive:

Class	Type	Suggested use
A	Eminently hydraulic	Structural work. Supplied hydrated only.
B	Semi-hydraulic	Masonry mortar, lime concrete, plaster undercoats
C	Fat lime	Finishing coats, whitewash; with a pozzolana, masonry mortar
D	Magnesium or dolomitic	Finishing coats, whitewash
E	Kankar lime	Masonry mortar. Supplied hydrated only.
F	Siliceous dolomitic	Plaster undercoats and finishing coats

Fat lime (class C) is the class IS 6278 names for whitewash and IS 2394 uses for finishing coats. It hardens by carbonation, taking carbon dioxide from the air, which the Specifications for Built Heritage Conservation (2021) by the Aga Khan Trust for Culture (AKTC) and Tata Trusts says can take weeks or months. It also notes that hydraulic lime is not easily available in India.

How to judge a bag: IS 712 requires the package to show the type and class, maker, date of manufacture and net weight, plus the slaking temperature for quicklime. The BIS mark is optional here, so read the label and date.

Slaking and maturing: where good lime plaster starts

Quicklime is never used as delivered. IS 1635:1992 prefers tank slaking: add lime to water (never water to lime), stir, run the milk of lime through a 3.35 mm sieve into a second tank, and let it settle into putty.

• Maturing: at least 3 days for fat and magnesian lime (classes C and D), but not more than 2 days for semi-hydraulic lime (classes B and F).
• From dry hydrated lime: make a thick cream and leave it at least 16 hours (C and D) or no more than 12 hours (B and F).
• Storage: keep putty under water. AKTC says it keeps for at least two weeks that way.
• Safety: slaking gives off intense heat; the code recommends goggles, respirators, gloves and gum boots.

Why it matters: IS 2250:1981 warns that unslaked particles keep hydrating in the mortar and cause popping, blowing and cracks. Our guidance: if nobody on site can slake properly, buy factory hydrated lime or ready putty.

Lime plaster vs cement plaster

The codes are IS 2394:1984 for lime plaster and IS 1661:1972 for cement and cement-lime plaster. For the cement itself, see our guide to OPC, PPC and PSC.

Breathability and old masonry

This is lime's strongest case. AKTC says pointing mortar should keep water out "but still allows the wall to breathe", and be weaker than the masonry, a sacrificial layer renewed instead of the bricks. ASI's National Conservation Policy (2014), article 4.17, asks that repair material match the original or be compatible with it, after analysing the original. The INTACH Charter (2004), article 4.5.1, says local materials and traditional technologies "must invariably be preferred". Our guidance: do not patch a lime-mortar wall with cement plaster.

Cracking

IS 2394 lists the causes: quick drying in hot weather, a strong mix on a weak background, poor bond, masonry still shrinking, unraked joints, and junctions between materials, which it suggests separating with a groove. Its rule: no coat stronger than the background or the coat beneath. Young lime plaster is also sensitive to shock and vibration.

Where lime is the wrong choice

IS 2394 says lime plaster is not suitable outside in heavy rainfall, in very damp places or where watertightness is needed. It takes knocks poorly (coarser sand, fibre or a little cement helps), and metal in contact with it can corrode. For rain on new walls, see our guide to waterproofing by climate.

How a lime plaster goes on

IS 2394 asks for joints raked at least 12 mm deep and a wall dampened, never soaked. Brick takes one or two coats, stone two or three; two-coat work on brick is about 10 mm plus 10 mm, then a finishing (neeru) coat of about 5 mm, lime and fine sand ground in equal parts. The first coat is beaten with wooden thapis, dented for key and kept damp 3 to 5 days.

The code allows guggal (1.5 kg per m³ of mortar), jaggery water, and fibre (1 kg per m³) in undercoats. AKTC adds belgiri for waterproofing, methi as a retarder, curd for binding and egg white in the final coat.

Curing: start 24 hours after finishing and keep it wet for 7 days, with dates marked on the wall.

Traditional finishes: araish, Chettinad, Madras plaster, lime wash and surkhi

Araish (Rajasthan)

Araish is Rajasthan's polished lime finish. Conservators of the Shekhawati Project, writing in the International Institute for Conservation's News in Conservation (2023), describe lime, marble powder, seashell powder, curd and pigment, polished with agate to a semi-shiny surface, and say only a few craftsmen still practise it. AKTC describes a related punning of equal parts lime putty and marble dust, 1 to 3 mm thick.

Chettinad plaster (Tamil Nadu)

AKTC calls it Chettinad plaster, vellai poochu or muthu poochu: lime and egg, extremely smooth, with a sheen. A 2020 report in 30 Stades describes six layers using lime, conch and shell powder, curd and egg whites, and counted seven artisans in Chettinad still using it. The INTACH Charter, article 4.5.2, cautions that shell lime in coastal areas may need substituting to protect ecosystems.

Madras plaster

IS 2394 still specifies it: a lime first coat, a 5 mm coat of 12 parts shell lime, 9 fine white sand and 1 marble powder, then 2 mm of the same mix stone-ground and polished with hard stones.

Lime wash

IS 6278:1971 calls for fresh fat lime, about 5 litres of water per kg of quicklime, left 24 hours and strained, with gum and a little salt to speed carbonation. New work needs at least two coats.

Surkhi

Surkhi is crushed burnt brick, a pozzolana. AKTC wants well-burnt or over-burnt brick, and IS 2250 says fat lime needs such a pozzolana for masonry mortar. CPWD still prices lime-surkhi-marble dust mortar.

Where to use lime today

• Restoring old buildings built in lime mortar: plaster, pointing and lime wash. Laterite walls are a case in point; see our laterite construction guide.
• Interior walls and ceilings of new houses, which IS 2394 says lime plaster generally suits.
• Feature walls in araish, Madras or Chettinad finish, done by a specialist.
• Not on exposed walls in high-rainfall areas, wet rooms or knock-prone spots. For the rest of the house, see building materials by climate and region.

Indicative rates

The 2023 DSR has no lime plaster item; Karnataka's comes from its heritage chapter, written for buildings affiliated to the ASI. For current rates, check your state PWD Schedule of Rates and get dated written quotes naming the lime class.

Who still does it, and how to hire

ASI's policy, articles 6.01 to 6.06, calls traditional masons and craftspersons "living repositories" of building traditions and asks that their skills be passed on; INTACH's charter does the same for raj mistris. They are few, as the Shekhawati and Chettinad reports show. Our guidance:

• Ask to see finished work that is at least a few monsoons old.
• Ask for a sample panel on your wall before the full job.
• Agree in writing the lime class, slaking plan, coat thicknesses, gaps and curing.
• For a listed or protected building, bring in a conservation architect; ASI's policy and the AKTC specifications both ask for the original to be analysed before a new mix is chosen.

FAQ

Is lime plaster better than cement plaster?

For old lime-mortar walls and interiors, yes: it matches the original, stays weaker than the masonry and lets the wall breathe. On exterior walls in heavy rain, IS 2394 says lime is not suitable.

What is araish plaster?

A polished Rajasthani lime finish of lime, marble powder, shell powder and curd, burnished with agate to a semi-shiny surface. Few craftsmen still do it.

How long does lime plaster take to cure?

Keep it wet for 7 days from 24 hours after finishing, with 3 to 5 days between coats. It goes on hardening for weeks or months.

What does lime plaster cost per sq ft?

Karnataka's 2023-24 schedule gives ₹999 per m², about ₹93 per sq ft, for 20 mm in two coats, against about ₹31 per sq ft for 20 mm cement plaster. Treat both as indicative.

Consult an architect on MOA who can judge your walls and climate and specify the right plaster.

Sources

• Bureau of Indian Standards: IS 712:1984, Specification for Building Limes, via Public.Resource.Org (accessed 18 Oct 2026)
• Bureau of Indian Standards: IS 1635:1992, Field Slaking of Building Lime and Preparation of Putty, via Public.Resource.Org (accessed 18 Oct 2026)
• Bureau of Indian Standards: IS 2394:1984, Application of Lime Plaster Finish, via Public.Resource.Org (accessed 18 Oct 2026)
• Bureau of Indian Standards: IS 1661:1972, Application of Cement and Cement-Lime Plaster Finishes, via Public.Resource.Org (accessed 18 Oct 2026)
• Bureau of Indian Standards: IS 2250:1981, Preparation and Use of Masonry Mortars, via Public.Resource.Org (accessed 18 Oct 2026)
• Bureau of Indian Standards: IS 6278:1971, Whitewashing and Colour Washing, via Public.Resource.Org (accessed 18 Oct 2026)
• Aga Khan Trust for Culture and Tata Trusts: Specifications for Built Heritage Conservation (2021), chapter 1, Lime Work (accessed 18 Oct 2026)
• Archaeological Survey of India: National Policy for Conservation of the Ancient Monuments, Archaeological Sites and Remains (2014), via NITI for States (accessed 18 Oct 2026)
• INTACH: Charter for the Conservation of Unprotected Architectural Heritage and Sites in India (2004), full text via Architexturez (accessed 18 Oct 2026)
• International Institute for Conservation: The Shekhawati Project, News in Conservation 98 (2023) (accessed 18 Oct 2026)
• 30 Stades: Chettinad's masons slowly revive centuries-old lime-egg wall plaster technique (2020) (accessed 18 Oct 2026)
• CPWD: Delhi Schedule of Rates 2023, Volume 1 (accessed 18 Oct 2026)
• CPWD: Delhi Schedule of Rates 2023, Volume 2 (accessed 18 Oct 2026)
• Karnataka PWD: Schedule of Rates for Buildings 2023-24, Volume 2, listed on the 2023-24 SR page (accessed 18 Oct 2026)