AMOUNT OF CEMENT USED IN AN AVERAGE 3 BEDROOMED HOUSE IN KENYA.

AMOUNT OF CEMENT USED IN AN AVERAGE 3 BEDROOMED HOUSE IN KENYA.

Cement cost takes an average of 35% of the total cost of construction of an average house basing on a low cost finish overall estimate of KES 20,000per m2. This is approximately KES 7,000 per m2.

The amount of cement used in total for an average 3 bedroomed residential house of 100m2 in plinth area is 958 bags at a cost of KES 691,000 basing on a price of KES 720 per 50kg bag.

A square meter of building in Kenya will use 9.6 bags.

2 BEDROOMED FLAT.

The average 2 bedroomed house in a middle class area such as Ruaka, Rongai, Kitengela, Ruai is approximately 60m2 in plinth area. This translates to 60m2 x 9.6bags=546bags costing KES 414,000.

A block of 2 bedroomed flats in the middle class neighborhoods standing on a 1/8th acre can contain 20 units. This means the total cement used will be 20 units x 546bags per unit=10,920 bags costing 7,800,000 KES.

SHOPS AND SINGLE ROOMS 1Oft by 10ft.

The average 10ft by 10ft room used as a shop or single room residence is approximately 10m2 in plinth area. This translates to 10m2 x 9.6bags=96bags of cement costing KES 69,100.

The breakdown is as below.

Foundation.

weight tonnes cement bags cement price
cement sand ballast
Blinding1.4.8

0.461538

1.969231

3.938462

9.230769

6646.154

Footing1.2.4

3.214286

6.857143

13.71429

64.28571

46285.71

Floor1.3.6

5.4

17.28

34.56

108

77760

181.5165

130691.9

WALLING. Ratio of 1.4

weight tonnes cement bags cement price
cement sand ballast

23.90625

76.5

478.125bags

34425

BEAMS AND COLLUMNS. Ratio 1.2.4

weight tonnes cement bags cement price
beams cement sand ballast

5.571429

11.88571429

23.77143

111.4286bags

80228.57

collumns

0.857143

1.828571429

3.657143

17.14286bags

12342.86

FLOOR PLASTER. Ratio 1.3

weight tonnes cement bags cement price
cement sand ballast

1.875

6

0

37.5bags

27000

WALL PLASTER. Ratio 1.4

weight tonnes cement bags cement price
cement sand ballast

5.97

25.472

0

119.4bags

85968

EXTERNAL KEYING. Ratio 1.4

weight tonnes cement bags cement price
cement sand ballast

0.672

2.8672

0

13.44bags

9676.8

ACTUAL SITUATION ON THE GROUND.

In most small scale residential projects, the house owners usually rely on the local Fundi expertise on the mix ratio of cement. The usual tools used to measure the volumes are spades, wheel barrows and 20 liter water buckets.

8 wheelbarrow of sand/ballast make 1 tonne.

Four wheelbarrows are used to mix 1 bag of cement to 8 bags of ballast.

I bag of cement has 0.035 cubic meters in volume.

1 wheelbarrow has the below volume.

Assuming sand has a density of 1600kg/m3 and 8 wheelbarrows make 1 tone, 1 wheelbarrow has 1000/8=125kg.

1 wheelbarrow of sand has 0.08 Cubic meters in volume.

This sand volume per wheel barrow when compared to cement volume per bag gives a ratio of 1 cement volume to 2 sand volumes.

LOCAL FUNDI MIX.

The usual mix used by local fundis of 1 bag cement to 4 bags sand is actually 1 cubic meter cement to 8 cubic meters sand to 16 cubic meters ballast.

A ratio of 2 bags cement to 4 wheelbarrows sand to 8 wheelbarrows ballast is 1 to 4 to 8 which is still low for concrete works such as foundation footings and beams which require a ratio of 1 to 2 to 4 or 1 to 3 to 6.

This type of mix works well for single storey residential houses.

BUILDING COLLAPSE.

In the event that the ratio of 1 bag cement to 4 wheelbarrows sand to 8 wheelbarrows ballast is used for a building that is several storeys high, serious risk of collapse is imminent due to a very weak cement ratio. This could be the reason for the various building collapse being witnessed in Kenya and recently in Tanzania and India.

Francis Gichuhi Kamau, Architect.

info@a4architect.com

0721410684.

Francis Gichuhi (692 Posts)

Architect Francis Gichuhi . B.Arch. University of Nairobi. Registered Architect, Kenya. Member, Architectural Association of Kenya. Contacts. email info@a4architect.com. Telephone +254721410684


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  5 comments for “AMOUNT OF CEMENT USED IN AN AVERAGE 3 BEDROOMED HOUSE IN KENYA.

  1. patrick
    November 20, 2015 at 3:56 pm

    Hi i love your informative website…looking forward to bookmarking it. anyways…im constructing a two room storey house back in my rural area for the annual stay-at-home visits. two room up two rooms down. one with15 by 10ft the other 8 by 8ft.could you do me the estimates for cement sand and ballast. will appreciate. and which ratio should i use 1:4:8 or 1:3:6? considering its not a big construction. regards >> PK

  2. patrick
    November 20, 2015 at 3:57 pm

    AND NUMBER OF CEMENT TO BE USED. KINDLY

  3. JImmy
    January 7, 2016 at 12:42 pm

    hii
    Thinking of making a 3 bedroom house my thinking is i make the blocks then use them for the construction.
    Ave had so many ratios of the number wheelbarrows of sand to one bag of cement.
    what would be the best ratio for this work?
    1:3?
    1:4?
    1:5?
    1:6?
    ………?

  4. Esther Lamwenya
    May 21, 2017 at 4:11 am

    have a house made of mad. I want to put some sand and cement on it to look nice. it is a four roomed house. how many bags of cement do I need?. both walls and floor

  5. May 23, 2017 at 8:52 am

    We offer state of the art elevators and escalators in Kenya. We hasve partnered with several overseas companies to produce and supply for our local markets for your kind of application.
    Office, Ho,e, Apartment, Hospitals , shopping malls etc.
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