How many cement bags required for 800 sq ft rcc roof slab | cement required for 800 sq ft roof | cement required for 800 sq ft slab | how much cement is required for 800 sq ft slab | how much cement do i need for 800 sq ft slab.

To pour a 800 square foot, 4″ thick RCC roof slab, you will need a total of 55 bags of cement, 5″ thick – 70 bags and 6″ thick – 84 bags cement with a 1:2:3 mix (cement: sand: aggregate) to achieve a concrete compressive strength of 3,000 psi in 28 days.

Cement is one of the important ingredient of concrete, generally it is mix in concrete due to adhesive and binding nature with fine and coarse aggregate. A small amount of lime is also added in concrete mix to increase the workability and strength of concrete.

There is different grade of concrete such as M20, M25, M30 and so on, used for RCC flat roof slab casting, in this article we used the nominal mix ratio 1:2:3 (1 part cement is mixed with 2 part sand and 3 part aggregate) those prepared mix concrete have compressive strength of 3000 PSI.

Generally roof slab thickness is kept about 4 inch thick at general a standard used for residential building and thickness of 5 to 6 inch for commercial use, in this article we calculate cement required for RCC roof slab at 4 inch, 5 inch and 6 inch thickness.

Roof slab casting is process of laying and putting concrete mix in horizontal direction and structure over brickwork. Cast of roof slab reinforcement main bar and cross bar in distributed over shuttering areas of roof slab and then we put concrete mix of M20 or m25 grade of concrete that is known as roof slab casting.

**How many cement bags required for 800 sqft roof slab?**

Roof slab casting is process of laying and putting concrete mix in horizontal direction and structure over brickwork. Cast of roof slab reinforcement main bar and cross bar in distributed over shuttering areas of roof slab and then we put concrete mix of M20 or m25 grade of concrete that is known as roof slab casting.

Generally one bag of Portland cement is weight around 50 kg and their density is 1440 kg/m3.

**Calculate how many cement bags required for 800 sq ft roof slab at 6 inch thick**

● Given details:-

1) thickness of roof slab = 6″

2) mix ratios = 1:2:3

3) Area of roof slab = 800 sq ft

4) Density of cement =1440kg/m3

5) 1 bag cement weight = 50 kg

● Calculation of wet volume of concrete:- you can determine quantity of concrete by calculating its volume by multiplying square footage of roof slab with their thickness such as – 1) thickness in feet = 6/ 12 = 0.5 feet, 2) wet volume of concrete = 800 sq ft × 0.5 feet = 400 cubic feet, thus you will need 400 cubic feet of wet volume of concrete for 800 sq ft rcc roof slab

● Dry volume:- we know that wet volume have voids and pore which filled with water and bubbles it can be remove by vibrator or compressor machine so more quantity of material is required that is dry volume. Volume of dry concrete is increased by 54%, so we can multiply 1.54 in wet volume to calculate dry volume. Dry volume of concrete = 400 cubic feet × 1.54 = 616 cubic feet. Thus you will need 616 cubic feet of dry volume of concrete for 800 sq ft rcc roof slab

● Mix ratio:- 1:2:3 mix ratio (1 part cement is mixed with 2 part sand and 3 part aggregate) is used for prepairing concrete mix. Add this mix ratio 1+2+3 = 6, part of cement in mix = 1/6.

● Calculate cement for 800 sq ft roof slab:-

1) cement quantity in cubic feet =1/6 × dry volume of concrete, 616 ÷6= 103 cubic feet approx

2) cement quantity in cubic meters =1/6 × dry volume of concrete ÷ 35.32, (616 ÷6) ÷ 35.32 = 2.92 cubic meters approx

3) cement quantity in kg = cement quantity in m3 × 1440 kg/m3 = 2.92 × 1440 = 4205 kg approx

4) cement quantity in No. of bags = cement quantity in kg ÷ 50 kg = 4205 ÷ 50 = 84 bags approx.

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**Conclusions**:-

For a 800 sq ft rcc roof slab casting at 6 inch thick, generally you will need 84 bags (around 4205 kg) of cement which is approximately equal as 103 in cubic feet or in 2.92 cubic meter by using 1:2:3 (cement: sand: aggregate) mix to gain 3000 Psi compressive strength of concrete in 28 days. Thus 84 bags of cement are required for 800 sq ft rcc roof slab at 6 inch thick.

Calculate how many cement bags required for 800 sq ft roof slab at 5 inch thick

● Calculation of wet volume of concrete:-

1) thickness in feet = 5/ 12 = 0.416 feet, 2) wet volume of concrete = 800 sq ft × 0.416 feet = 333 cubic feet

● Dry volume of concrete = 333 cubic feet × 1.54 = 513 cubic feet. Thus you will need 513 cubic feet of dry volume of concrete for 800 sq ft rcc roof slab at 5 inch thick

● Calculate cement for 800 sq ft roof slab:-

1) cement quantity in cubic feet =1/6 × dry volume of concrete, 513 ÷6= 85.5 cubic feet approx

2) cement quantity in cubic meters = volume of concrete in cubic feet ÷ 35.32, (85.5 ÷ 35.32 = 2.43 cubic meters approx

3) cement quantity in kg = cement quantity in m3 × 1440 kg/m3 = 2.43 × 1440 = 3499 kg approx

4) cement quantity in No. of bags = cement quantity in kg ÷ 50 kg = 3499 ÷ 50 = 70 bags approx.

**Conclusions**:-

For a 800 sq ft rcc roof slab casting at 5 inch thick, generally you will need 70 bags (around 3499 kg) of cement which is approximately equal as 85.5 in cubic feet or in 2.43 cubic meter by using 1:2:3 (cement: sand: aggregate) mix to gain 3000 Psi compressive strength of concrete in 28 days. Thus 70 bags of cement are required for 800 sq ft rcc roof slab at 5 inch thick.

Calculate how many cement bags required for 800 sq ft roof slab at 4 inch thick

● Calculation of wet volume of concrete:-

1) thickness in feet = 4/ 12 = 0.33 feet, 2) wet volume of concrete = 800 sq ft × 0.33 feet = 264 cubic feet

● Dry volume of concrete = 264 cubic feet × 1.54 = 407 cubic feet. Thus you will need 407 cubic feet of dry volume of concrete for 800 sq ft rcc roof slab at 5 inch thick

● Calculate cement for 800 sq ft roof slab:-

1) cement quantity in cubic feet =1/6 × dry volume of concrete, 407 ÷6= 67.83 cubic feet approx

2) cement quantity in cubic meters = volume of concrete in cubic feet ÷ 35.32, (67.83) ÷ 35.32 = 1.92 cubic meters approx

3) cement quantity in kg = cement quantity in m3 × 1440 kg/m3 = 1.92 × 1440 = 2765 kg approx

4) cement quantity in No. of bags = cement quantity in kg ÷ 50 kg = 2765 ÷ 50 = 55 bags approx.

**ALSO READ :-**

**How many cement bags required for 3000 sq ft rcc roof slab**

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**How many cement bags required for 2000 sq ft rcc roof slab**

**How many cement bags required for 1800 sq ft rcc roof slab**

**How many cement bags required for 1400 sq ft rcc roof slab**

**Conclusions**:-

For a 800 sq ft rcc roof slab casting at 4 inch thick, generally you will need 55 bags (around 2765 kg) of cement which is approximately equal as 67.83 in cubic feet or in 1.92 cubic meter by using 1:2:3 (cement: sand: aggregate) mix to gain 3000 Psi compressive strength of concrete in 28 days. Thus 55 bags of cement are required for 800 sq ft rcc roof slab at 4 inch thick.

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**Final conclusions:**–

For a 800 sq ft rcc roof slab casting at 4 inch thick, generally you will need 55 bags (around 2765 kg) of cement, at 5 inch thick – 70 bags (around 3499 kg) and at 6 inch thick – 84 bags (around 4205 kg) of cement are required by using 1:2:3 (cement: sand: aggregate) mix to gain compressive strength of 3000 Psi concrete in 28 days.