By Mizhaab, E veedu
Gypsum plastering is a method of plastering that is widely accepted in our times.
What exactly is gypsum plastering?
What are the differences between cement plastering and gypsum plastering?
What are the disadvantages? Will the cost go down?
Let’s start with,
What is gypsum? How is it made?
Gypsum is a calcium silicate dihydrate.
It is available to us in three ways
The first is mining from the Earth Crest
Available as Salt Manufacturing Processing by Product – This type of gypsum is called marine gypsum.
Available while manufacturing fertilizers, as well as a thermal power plant by-product.
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What does the work site do?
Gypsum is mixed with water and applied directly, sometimes as a bonding agent on smooth concrete, without the need for curing.
How gypsum plastering differs from cement plastering
- Gypsum plastering does not require watering, painting can be done the next day if required, generally up to 10 days after tapping, saving time and water
- Cement plastered putty is used for finishing, but not in gypsum,
- Gypsum plastering is less likely to crack, However, When cement is mixed with water, a heat is released from it. This is called heat of hydration, so the heat coming out is more likely to cause the cement plastering to crack.
- Gypsum plastering is not commonly used to paint exteriors or kitchens.
- Gypsum plastering should not be used on wet areas, as gypsum will absorb water quickly, and if used on wet areas, it may peel off over time.
- Experienced people say that the heat inside a gypsum plastered room is low, in short the advantages of gypsum plastering over sand cement plaster
- Faster construction.
- Sand cement plaster requires 28 days of curing, and then the surface needs time to smooth again. It can be finished in 3 days with gypsum plaster
- Saves water.
- Water Curing. Sand cement plaster requires 0.6 kg / m2 of water per day. For a project with an area of 1,00,000 square meters you need 60,000 litres of water per day. If the minimum curing time of sand cement plaster is 28 days, the quantity is multiplied.
- There is a possibility of cracks in the sand cement plaster (cracks due to shrinkage). Gypsum plaster does not have these problems.
- Lightweight building construction.
- The density of gypsum plaster (700 kg / m3) is 50% lower than that of conventional sand cement plaster (1860 kg / m3). Therefore the use of gypsum plaster for wall plastering reduces the structural weight of the building.
- Low electricity bills.
- It has low thermal conductivity (0.25 W / m-K) compared to sand cement plaster (0.72 W / m-K). It helps to cool houses in summer and heat in winter, which saves energy costs.
Now let’s look at the cost
Things to be considered before you do!
When plastering, the exterior is 20mm thick and the interior is 12mm thick while the ceiling is 9mm thick.
Exterior – 20 mm
Interior – 12 mm
Ceiling – 9 mm
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The most suitable mix we can use for sharp swords is 1: 4
A mix of 1: 3 is recommended for ceilings.
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Cement with fly ash basil known as PPC grade cement is suitable for plastering
P sand or plastering sand should be used for tiling.
How much does a 1100 sqft house cost?
(The floor area is 1100 square feet, with slight variations depending on the length of the wall and the plan).
Let’s see how much plastering costs for a 1100 sq. ft house in general:-
Doors, excluding windows, will require plastering of 1400 square feet,
Specification: 1400 sqft, 2.6 Cum (cubic meter), 20 mm thickness
Material required: 20 bags of cement, 95 CFT P Sand.
Specification: 3500 sqft, 3.9 CUM, 12 mm
Material Required: 29 Bags Cement, 143 CFT P Sand
Specification: 850 sqft, 0.92 CUM, 9 mm
Material Required: 7 Bags Cement, 25 CFT P Sand
Shades / Terrace
Specification: 1600 Sqft, 3.9 CUM, 12 mm
Material Required: 29 Bags Cement, 143 CFT P Sand
Total = 86 bags of cement
414 CFT P Sand
Including wastage = 90 Bags Cement,
455 CFT P Sand
In short, the cost to us of plastering cement,
The rate at which cement comes is 90 bags of cement x Rate (460) = 41400
P Sand Rate 455 CFT x 56 (rate) = 25480
Labour cost = 7350 sqft (total square feet, not floor size) x 14 = 102900
Total = 169780
Now let’s see how the cost comes when plastering gypsum on an 1100 sqft house
As we have already learned, not all parts of a house can be plastered with gypsum.
If the exterior and interior bathroom walls are designed with gypsum board, we can do gypsum plastering on the rest of the ceiling, excluding the ceiling.
I.e. the walls of all the rooms near the house, (minus the area of adjoining windows and doors, but calculated on its borderline running feet)
Comes in at about 2500 square feet
There are a variety of gypsum plastering brands on the market, with prices ranging from 35–45 depending on quality and brand,
We can take a rate of around Rs. 35.
Then 2500 x 35 = 87500.
As mentioned earlier gypsum plastering cannot be done on all parts, then
Let’s look at the cost of plastering the rest of the cement.
Approximately for exterior + interior bathroom walls + ceiling cement plastering, (where gypsum plastering is not possible and / or the amount of a house that is not)
Cement bags = 67 x 460 = 30820
P Sand = 333 x 56 = 18648
Labour = 67900
Total = 117368
For plastering (gypsum) of a house of 1100 square feet approximate = 117368 + 87500 = 204868
The overall rate for cement plastering = 169780
Coming when plastering gypsum = 204868
So where does the cost go down?
Cost decreases at the finishing stage
If only cement plaster
* It should be whitewashed on top,
* Two coats should be locked
* Primer should be applied
* Then apply the paint
In case of gypsum plastering, apply a coat of primer and then direct paint.
Now let’s look at that one more expense
That is, according to the example we took (1100 sqft house) the gypsum plastered area was 2500 square feet and we got the rate
If that is a 2500 sq ft cement plaster, then the cost that comes there are as follows
Cement = 23 (Bags) x 460 (cement rate) = 10580
P Sand = 110 (Cft) x 56 (rate) = 6160
Labour = 35000
White cement = Material + Labour = 8750
2 Coat Putty = Material + Labour = 45000
Total = 105490
Remember the cost of plastering 2500 square feet of gypsum was ₹ 87500
On the other hand, if we use good quality ₹ 42 rated gypsum plastering, it will be 2500 x 42 = 105000.
In short, we learned
Gypsum plastering, which costs between Rs 40 and Rs 48 per square foot, is the usual cement plastered putty rate.
Gypsum plastering rated 35 to 37 will reduce the cost,
The advantages mentioned at the beginning are
1. There will be no crack
2. No curing process required
3. Water and electricity can be saved
4. Faster construction… .etc.
If you choose gypsum plastering considering these benefits, then gypsum plastering is definitely for you.
If the budget is very low, it is better to whitewash with ordinary cement plaster.