gyproc®

Plastering

Gyproc Plastering

Overview

Gypsum plastering is an environmental friendly alternative to traditional sand-cement application for internal plastering surfaces.

Gypsum plastering is also a faster application method for internal surfaces, since it does not require time consuming water curing process. Water curing process is mandatory for 20 – 21 days after sand-cement plastering to reduce shrinkage cracks arising due to heat of hydration.

Gypsum plaster is mixed with clean water in recommended proportion at site to make a consistent slurry. Gypsum plaster slurry is then applied at desired thickness on walls and ceilings by trained applicators, this process is called as Gypsum plastering.

Used for centuries in the construction space

Gypsum plaster had been used for centuries in the construction space and is time tested process for plastering interior walls. Gypsum plaster provides excellent thermal and acoustic properties while providing superior rich and smooth finish. Gypsum plastering is now very popular in India and today is preferred choice of builders in most metro markets like Mumbai, Pune, Bengaluru, Delhi NCR, Hyderabad and Chennai.

Gypsum Plasters – FAQ’s

Gypsum is chemically termed as Calcium Sulphate dihydrate (CaSO4 2H2O). There are three broad kinds of gypsum which are found across the world.

Naturally gypsum is found below the earth’s surface like other minerals and this gypsum is called Natural Gypsum. The Natural gypsum is mined and extracted below the earth’s surface using conventional means. In India, natural gypsum is found largely in Rajasthan.

Gypsum is also formed as a by-product of the salt manufacturing process and this gypsum is called Marine gypsum. In India marine gypsum is found in Tuticorin and Gujarat where the salt pans exist.

Thirdly gypsum is also formed as a by-product of industrial manufacturing processes like fertilizers, copper and power. The gypsum thus formed is called synthetic gypsum and is also referred to as phosphor gypsum & DSG depending on the type of manufacturing process.

Gypsum rock is converted into gypsum plaster by heating it at a temperature between 120°C and 160°C for a period of time to drive off some of the chemically combined water. This process converts the dihydrate gypsum into a hemi-hydrate (CaSO4.1⁄2H2O) with three quarters of the water removed. This is commonly referred to as Plaster of Paris (POP) or Stucco. This product typically has a very fast setting time of between 3 minutes and 6 minutes. Because of this fast setting the Plaster of Paris (POP) has very high wastage and tends to develop shrinkage cracks and hence is not suitable for use in plastering.

Gypsum plaster is formed when stucco or POP is mixed with special retarders and special additives to enhance its performance in terms of setting time, finish and coverage. This plaster is suitable for plastering and is commercially called Gypsum plaster.

Gypsum plaster sets and hardens by chemical recombination of the gypsum with water to provide a levelled surface that is ready for painting.

Gypsum Plasters in India is governed and adopted by Indian Standards Institution (IS:2547), drafted by Gypsum Building Materials sectional committee and finalized by the Civil Engineering Division Council.

Gypsum Plasters are tested on the basis of their physical and chemical properties. These tests are revised into two parts:

Part I deals with all Gypsum Plasters with or without “light weight aggregates”. This method covers the tests determining Normal consistency (%), setting time (minutes), compressive strength (N/mm2), transverse strength (N/mm2), soundness, expansion (%), freedom from coarse particles (residue on 150micron mesh) & bulk density (kg/M3).

Part II deals with Gypsum Plaster containing premixed “lightweight aggregates” and necessarily complying to IS: 2547 (Part 1).

This method of testing determines:

a. sum of soluble sodium and magnesium salts expressed as percentages of sodium oxide (Na2O) and Magnesium oxide (MgO) by mass.

b. free lime content % by mass

Above tests are conducted at regular intervals for all Saint Gobain Gyproc Plasters by authorised third party agencies.

Gypsum plaster is mixed with clean water in recommended proportion at site to make a consistent slurry. Gypsum plaster slurry is then applied at desired thickness on walls and ceilings by trained applicators, this process is called as Gypsum plastering.

Gypsum plastering is an environmental friendly alternative to traditional sand-cement application for internal plastering surfaces. Gypsum plastering is also a faster application method for internal surfaces, since it does not require time consuming water curing process. Water curing process is mandatory for 20 – 21 days after sand-cement plastering to reduce shrinkage cracks arising due to heat of hydration.

Gypsum plaster had been used for centuries in the construction space and is time tested process for plastering interior walls. Gypsum plaster provides excellent thermal and acoustic properties while providing superior rich and smooth finish. Gypsum plastering is now very popular in India and today is preferred choice of builders in most metro markets like Mumbai, Pune, Bengaluru, Delhi NCR, Hyderabad and Chennai.

Traditionally sand-cement plaster was extensively used for levelling interior walls on Bricks, AAC Blocks, Concrete Blocks & RCC surfaces. In certain markets to achieve crack free and smooth finished walls, 3mm to 6mm of gypsum plaster is applied over sand-cement plastered surface, this is called as gypsum punning.

No Shrinkage Cracks

Saint-Gobain Gyproc gypsum plaster is completely free from shrinkage cracks due to is self-setting properties.

Shrinkage cracks occurs in sand-cement plaster due to sudden change in moisture of concrete arising out of heat of hydration. To control heat in concrete and reduce shrinkage cracks in sand-cement plaster, water curing process is mandatory for 20-21 days. Water curing is labor intrinsic and time consuming. Monitoring of water curing process for large projects is a big challenge.

Faster Construction

Saint-Gobain Gyproc gypsum plaster does not require any water curing. Gypsum Plaster with adequate initial and final setting time improves workability and provides a ready paintable surface within 3-4 days. This is net savings of 24 days of construction time.

Sand-cement plaster is mixed at site in various proportions (4:1 or 5:1) to arrive at desired strength. Sand-cement plaster requires total 28 days (water curing + POP punning) complete curing of surface to attain paintable surface.

Light weight Construction

Saint-Gobain Gyproc gypsum plaster is 50% lighter in weight (density of approximately 700Kg/m3) in comparison to traditional sand-cement plaster (density of 1860 kg/m3). Using Saint-Gobain Gyproc gypsum plaster for internal plastering thereby decreases the load on the building. Technologically Saint-Gobain Gyproc Gypsum Plaster is light weight but still conforms to standards of the compressive strength required for Internal plastering.
Saint-Gobain Gyproc Gypsum plaster comprehensive strength ranges from 8N/mm2 to 4N/mm2**

**Above parameters are tested under lab conditions.

No Curing (Water Saving)

Saint-Gobain Gyproc gypsum plaster gives freedom from water curing process thus saving cost of water and labour.

Sand-cement plaster requires water for curing to the tune of 0.6 kg/m2/day. A project of 1 Lac sq-m will require water to the tune of 60000 liters daily. With minimum curing time of sand cement plaster as 25-28 days, the quantity multiplies manifold.

Water required for sand-cement per square feet is 1.56 Litres

Water required for Gypsum plaster per square feet is 0.00092 Litres

Elimination of River Sand

Saint-Gobain Gyproc gypsum plaster comes in ready to use bags. Just addition of Saint-Gobain Gyproc gypsum plaster to clean water at site in prescribed proportion and we are ready for plastering. Gypsum plaster is a most proven alternative method to Sand-cement plaster for internal plastering applications. River sand mining is strictly banned in many states of India.

GREEN Building Certified

Saint-Gobain Gyproc gypsum plasters are infinitely recyclable.
Saint-Gobain Gyproc gypsum plasters are GRIHA and GreenPro certified. “GRIHA and GreenPro” certifies that the Saint-Gobain Gyproc gypsum plasters are environment friendly throughout its Life cycle.
Griha council is joint initiative of “Ministry of New and Renewable Energy”, “Government of India” and “The Energy and Resources Institute (TERI)”. GreenPro is an initiative by Indian Green Building council (IGBC).
Saint-Gobain Gyproc gypsum plasters also conforms to LEED requirements which helps in getting “US Green Building Certification” (USGBC).

Reduced Electricity Bills

Saint-Gobain Gyproc gypsum plasters have low thermal conductivity (0.25 W/m-K) as compared to Sand Cement Plaster (0.72 W/m-K). Lower the thermal conductivity of material, higher the insulating properties. Lower thermal conductivity helps in keeping house cool in summer and warm during winter which in turn save energy cost.

The exact difference in temperature can be calculated basis various parameters and quite complex theoretical calculation.

  • Outside temperature
  • Thickness of Plaster
  • Heat transmission rate
  • Dimension of the indoor rooms etc.

Environmental Sustainable

Saint-Gobain Gyproc gypsum plasters are designed to focus on solutions related to energy, climate, water. Saint-Gobain Gyproc gypsum plasters are infinitely recyclable.
Saint-Gobain Gyproc gypsum plasters are GRIHA and GreenPro certified.
Griha council is joint initiative of “Ministry of New and Renewable Energy”, “Government of India” and “The Energy and Resources Institute (TERI)”. GreenPro is an initiative by Indian Green Building council (IGBC).
GRIHA and GreenPro certifies that the Saint-Gobain Gyproc gypsum plasters are environment friendly throughout its Life cycle.
Saint-Gobain Gyproc gypsum plasters also conforms to LEED requirements which helps in getting “US Green Building Certification” (USGBC).

Sand-cement Plaster has two major variables, cost of both vary every month depending on the market demands. River sand mining is banned in many cities of India resulting in sharp increase of cost and inconsistent supplies. Depending on location, cost of Sand-cement plastering for 16-18mm thickness ranges between Rs. 23-27 per Square feet (labour + material).

Loss of sand during transit from distributor to site is approximately 5%-7%.
Moving sand in open barrow from storage heaps to plastering area, incurring loss of 5%-10%.
Sand is then manually sieved to remove large sized pebbles, there by incurring loss of 5%.
Mixing process of Sand & cement generally takes place on floor, adding to another 5% to 7% wastages.
Due to these inefficiencies in sand-cement plastering cost further goes up by another 20-30%.

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Saint-Gobain Gyproc plasters are packed in high quality attractive 20Kgs & 25Kgs bags, these are easily transported and can be safely handled at site.

Saint-Gobain Gyproc plasters are manufactured in our World class manufacturing units in Mumbai, Bangalore, Rajasthan. Saint-Gobain Gyproc plasters are mixed with water in buckets with no loss or minimal loss of material. Gypsum plaster slurry is then applied directly over properly prepared surfaces on Bricks, Blocks, RCC etc. Saint-Gobain Gyproc plaster can be applied from 6mm thickness to 18mm thickness in one coat, with no shrinkage cracks. Saint-Gobain Gyproc plasters is cost effective due to higher productivity and reduction in construction time by 24 days.

Gypsum plastering at 13mm thickness will cost in range of Rs.22-30/- per square feet,

** prices vary depending on distance of project from factory, scale of work, skilled labour’s availability in towns.

Gypsum plaster by design has definite savings

  • Reduction in application cost of Plaster of Paris (POP) upto Rs.8-10 per Sq ft
  • Reduction in cost of water curing activity. (Rs.1 Per SFT)
  • No repairing cost due to improper water curing
Comparision between Gyproc plasters and Sand Cement Plaster
Gyproc Plasters SC Plaster
Shrinkage Cracks No Yes
Water Saving 0.00092 Lit / sft 1.17 Lit / sft
Time saving 3 days ready for painting 21 days for painting
Labour Labour Friendly process Labour intensive
Density 880 Max Kg/M3 1400 Kg/M3
Availability Ready to use bags Sand availability is an big issue
Ingredients Ready mixed powder & Water Sand, Cement & Water
Quality assurance IS2547 part 1 & 2 No
Green Credentials Griha & Green pro No

Gypsum, a hydrated calcium sulphate (CaSO4. 2H2O) is white or pale yellow coloured depending on the sources. Saint-Gobain Gyproc gypsum plasters are manufactured with high purity gypsum and processed at fully automated machineries thus giving consistent quality. Saint-Gobain Gyproc gypsum plasters is further blended with special additives and retarders to make it suitable for Gypsum plastering. Special retarders added in Saint-Gobain Gyproc plasters increases working time for plastering (setting time from 15 – 25 Minutes) thereby reducing wastages in bucket and spillage during application (maximum wastage 5%). Saint-Gobain Gyproc gypsum plasters with special additives makes it light weight and increases productivity by 20%

Plaster of Paris (POP) found in most parts of India are manufactured with low purity and manually operated machines producing inconsistent quality. Plaster of Paris (POP) with low purity and inconsistent quality have lower setting time ranging between 3 min to 6 min, resulting in higher wastage in buckets (Minimum 10% - 20%). Due to inconsistent quality of Plaster of Paris (POP) it develops shrinkage cracks and hence is not suitable for plastering.

Saint-Gobain Gyproc plasters offer added benefits viz. higher coverage and less wastages

Saint-Gobain Gyproc plasters have lower density as compared to basic stucco plaster available in the market. The average density of our Saint-Gobain Gyproc plasters is approximately 700 kg/m3 which are significantly lower than basic stucco (1000 kg/m3) thus providing 30% higher coverage.

Saint-Gobain Gyproc plaster are manufactured at fully automated factories to deliver consistent quality and higher setting time of 15-25 minutes. Thus giving freedom to use entire bag of Saint-Gobain Gyproc plasters without wastages.

Comparision between Gyproc plasters and Plaster of Paris (POP)
Gyproc Plasters Local POP & Traded Gypsum
Cracks No Yes
Repairing Cost Minimum High
Density 880 Max Kg/M3 1080 Kg/M3
Wastages Lower wastages due to Higher setting time 30% Higher wastages due to Lower Setting time
Productivity 50% Higher Productivity Lower Productivity
Availability World class facility with strategically located plants unorganised local plants
Green Credentials Griha & Green pro No

Gypsum Plastering is a building material used for decorating internal walls and ceilings to provide even, smooth, and durable finished surface. Gypsum plaster also preserves and protect internal surface.

Gypsum plaster comes when mixed with water in recommended proportion is applied on prepared surface to give a perfect finish for painting.

gypsum is naturally found material and have withstand its natural form for decades. Gypsum had been used for internal plastering from centuries in Egypt. It is found intact even today at many tombs and pyramids. Modern construction in India have accepted this from decades, there are many projects done by Gyproc Gypsum plasters 2-25 years ago have shown remarkable results. We can easily say now life of gypsum is same life of building.

No, It’s been proved Gypsum had been used for internal plastering in Egypt centuries ago. Tombs and Pyramids built in Egypt were internally plastered by gypsum.

Yes, Gypsum plaster is processed form of Calcium Sulphate hemihydrate which is highly durable and stable. Mineral Gypsum is Inert, completely recyclable making it ecofriendly. Further more gypsum plaster manufactured by Saint Gobain Gyproc are approved by Griha and GreenPro.

No, Gypsum plaster can only be used on Internal Walls

Step 01: Smoothen the damaged areas with a Scraper

The first step is to prepare the area by removing any loose or flaking plaster. Use a cold chisel and ball peen hammer to chip away the damaged plaster. use a scraper to remove excess debris. Take care not to hit too hard with the hammer as it could damage the behind the plaster. This process might make the hole larger, but will give you a clean area in which to apply the new plaster.

Step 02: Mix New Plaster

Once the surface preparation is complete, mix up only the amount of plaster needed for the repair. Follow the instructions on the packaging to ensure the proper mixture. Mix it to the consistency.

Step 03: Apply the Plaster Mix to the Damaged Area

Apply the mixture with the Plaster Trowel and spread it over the hole. Cross-scratch the first coat as it begins to set to allow the second coat to adhere well.
If needed, apply Saint Gobain Gyproc Glass Fiber Mesh to the wall to fill in a larger and bumpy areas. First, apply a thin layer of plaster and then apply the Saint Gobain Gyproc Glass Fiber Mesh. Apply more plaster over the Saint Gobain Gyproc Glass Fiber Mesh and use the Plaster Trowel to smoothen the surface until it's even with the wall Once the first layer has dried, apply a second layer. Apply another layer and cross-scratch as did the first time. Allow it to dry thoroughly before you continue.

Step 04: Sand and Paint

Sand the area smooth with the sandpaper block, then prime and paint as per the paint company instruction.

Step 01: Smoothen the damaged areas with a Scraper

The first step is to prepare the area by removing any loose or flaking plaster. Use a cold chisel and ball peen hammer to chip away the damaged plaster. use a scraper to remove excess debris. Take care not to hit too hard with the hammer as it could damage the behind the plaster. This process might make the hole larger, but will give you a clean area in which to apply the new plaster.

Step 02: Mix New Plaster

Once the surface preparation is complete, mix up only the amount of plaster needed for the repair. Follow the instructions on the packaging to ensure the proper mixture. Mix it to the consistency.

Step 03: Apply the Plaster Mix to the Damaged Area

Apply the mixture with the Plaster Trowel and spread it over the hole. Cross-scratch the first coat as it begins to set to allow the second coat to adhere well. If needed, apply Saint Gobain Gyproc Glass Fiber Mesh to the wall to fill in a larger and bumpy areas. First, apply a thin layer of plaster and then apply the Saint Gobain Gyproc Glass Fiber Mesh. Apply more plaster over the Saint Gobain Gyproc Glass Fiber Mesh and use the Plaster Trowel to smoothen the surface until it's even with the wall Once the first layer has dried, apply a second layer. Apply another layer and cross-scratch as did the first time. Allow it to dry thoroughly before you continue.

Step 04: Sand and Paint

Sand the area smooth with the sandpaper block, then prime and paint as per the paint company instruction.

Step 01: Smoothen the damaged areas with a Scraper

The first step is to prepare the area by removing any loose or flaking plaster. Use a cold chisel and ball peen hammer to chip away the damaged plaster. use a scraper to remove excess debris. Take care not to hit too hard with the hammer as it could damage the behind the plaster. This process might make the hole larger, but will give you a clean area in which to apply the new plaster.

Step 02: Mix New Plaster

Once the surface preparation is complete, mix up only the amount of plaster needed for the repair. Follow the instructions on the packaging to ensure the proper mixture. Mix it to the consistency.

Step 03: Apply the Plaster Mix to the Damaged Area

Apply the mixture with the Plaster Trowel and spread it over the hole. Cross-scratch the first coat as it begins to set to allow the second coat to adhere well. If needed, apply Saint Gobain Gyproc Glass Fiber Mesh to the wall to fill in a larger and bumpy areas. First, apply a thin layer of plaster and then apply the Saint Gobain Gyproc Glass Fiber Mesh. Apply more plaster over the Saint Gobain Gyproc Glass Fiber Mesh and use the Plaster Trowel to smoothen the surface until it's even with the wall Once the first layer has dried, apply a second layer. Apply another layer and cross-scratch as did the first time. Allow it to dry thoroughly before you continue.

Step 04: Sand and Paint

Sand the area smooth with the sandpaper block, then prime and paint as per the paint company instruction.

No, complete removal of paint is required for getting a plastering done on Walls.

It depends on the setting time and drying time of plaster. Saint Gobain Gyproc plasters if correctly applied as per instruction will dry in 3-5 days (in normal conditions), though there are various factors affecting drying time Viz. current temperature, humidity etc. Painting activity should be carried out strictly after the plaster is completely dried.

A primer undercoat is a preparatory coating hence is recommended to apply thin coat of putty (optional) and one coat of primer to reduce patchy appearance and overall consumption of expensive paints. Moreover, primer ensures better adhesion of paint to the surface thereby increasing paint durability.

Air entrapment and less adhesion between gypsum plaster with back ground surface results in knocking sound in plasters. Ensuring proper preparation of surface before application of plaster will eliminate the chance of debonding and knocking sound. It is highly recommended to use Saint Gobain Gyproc Bondit on RCC (Concrete) surface before plastering also, pre-wetting on Bricks blocks and other surfaces will reduce the changes of debonding and knocking sound.

Saint-Gobain Gyproc is specialized in execution of Large and mega projects for internal plastering in major cities of India. Saint-Gobain Gyproc offers a host of services that are needed for large and mega projects that help make appropriate choices for their plastering needs. Currently Saint-Gobain Gyproc have supported in successful completion of projects like residential buildings, hospitals, hotels and government organizations.

Mockup

Mockups are conducted by Saint-Gobain Gyproc plasters at large projects. This activity helps to get coverage per square feet of Saint-Gobain Gyproc plasters in actual site conditions. Coverage derived at site will support the project team to calculate “cost of material” per square feet.

Preferred applicators

Saint-Gobain Gyproc can recommend gypsum plastering contractors capable of executing large projects. These gypsum plastering contractors are regular users of Saint-Gobain Gyproc plasters and have a team of trained applicators to deliver “superior quality”, “higher productivity”, “less wastages” at site and “follow safety guidelines”.

Technical Support

Saint-Gobain Gyproc have technically equipped and trained technologists. Saint-Gobain Gyproc technologists regularly conduct inspection during their site visits. During site Inspection, technologist observe application methods followed at site and suggest improvements wherever required. “Plastershala” is training provided to site applicators by our trained personnel. Plastershala are conducted with prior approval from project managers at regular intervals to improve labour productivity.

Site Delivery

In some metros, Saint-Gobain Gyproc plasters reach** directly to projects from manufacturing plants or warehouses. You can be rest assured about genuine Saint-Gobain Gyproc plasters reaching your project. There is no need of spending time in arranging vehicles for picking material from distributor.

**Depending on location, minimum order quantity is required for site delivery.

In large projects, it is observed to have uneven walls. Best time to get it rectified is during erecting the wall itself but there are ways to get it rectified during gypsum plastering also.

Saint-Gobain Gyproc plasters are applied directly over various surfaces and is executed in four stages:

Step1 - Setting out to achieve right angled corners between walls and floors with 3-4-5 method. Dabs are placed at fixed distance and thickness as required after proper calculations.

Step 2 - Making level strips with Saint-Gobain Gyproc plaster joining 2 Dabs from top to bottom.

Step 3 - Filling Saint-Gobain gypsum plaster between two level strips using appropriate plastering tools.

Step 4 – Final finishing to remove small unfilled portions and give smooth finish.