Quantity of cement and sand in 1m2 of Masonry walling in Nairobi, Kenya.

A 1m2 of masonary walling, assuming a 200mm/9inch stone thickness, will be as below.

Horizontal mortar.

Surface area =0.2m x 1m=0.2m2.
5 Surface levesl in 1m2 =5 x 0.2m2=1m2 For horizontal mortar joining the stones.

Vertical mortar.
Surface area=0.2 x 0.2=0.04m2.
15 vertical surfaces in 1 m2 of wall=15x 0.04=0.6m2.

Total surface area =0.6 + 1=1.6m2.

Volume = assuming a 1 inch/0.03m thickness =0.03 x 1.6=0.048 m3 of cement sand mortar per 1 m2.

Ratio of cement to Sand for walling mortar.
Assuming a cement/sand ratio of 1 to 8, the volumes will be as below.

4 sand 1 cement.
The usual mix by fundis in Kenya for cement sand mortar for joining and plaster is 4 wheel barrows of sand to 1 bag of cement.
2 bags of cement are equal to 1 wheelbarrow.
This translates to 2 bags cement to 8 wheel barrows of sand or a ratio of 1 to 8.

Sand volume will be 8/9 x 0.048m3=0.042m3

Cement volume will be 1/9 x 0.048m3=0.0053m3.



Sand density is 1.6 tonnes per m3.
Therefore, 0.042m3 of sand will weigh 0.07 tonnes=70kg.

1 tonne of sand costs kes 2,000.

0.07 tonnes of sand will cost kes 137 .

Cement density is 1.6 tonnes per m3.
Therefore, 0.0053m3 of sand will weigh 0.009 tonnes=9kg.

1 tonne of cement costs kes 14,000, Equivalent to 20 bags cement @kes 700 per bag.

9kg of cement will cost 9/50 x kes 700=kes 126 for 1 m2 of walling.

Total cost of cement/sand mortar will be 126 + 137=kes 263 per m2.


A fundi plus one mtu wa mkono will complete 150 stones per day.

1 stone is 0.2 x 0.4=0.08m2. 150 Stones are 12m2 of stone wall surface per day.

Labour cost is kes 800 for a fundi plus kes 400 for a mtu wa mkono =kes 1200 per day.

Cost of labour for 1 m2=kes 1200/12m2=kes 100.

Total cost of cement, sand plus labour =kes 363 per m2.

In 1 m2 of masonry stone walling,

costs are as below
stone 13 pieces@kes 50=kes 650
Sand=kes 137
Cement=kes 126
Total =kes 1013

Sand has increasingly become more expensive than cement.This is because of environmental concerns on river sand harvesting hence heavy taxes levied on sand harvesters. Labour is also threatening to surpass the estimates given due to the increased higher costs of living around Nairobi.
Cement prices have even gone lower, with Simba cement reducing their prices to around kes 600 per bag recently.
Stone prices will also increase due to rules limiting the tonnage of lorries travelling along Thika super highway. Juja is the largest supplier of machine cut stones in Nairobi hence affected by Thika road tonnage limit where the lorries are now carrying less tonnage for the same transport cost.

Francis Gichuhi Kamau, Architect.


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


  10 comments for “Quantity of cement and sand in 1m2 of Masonry walling in Nairobi, Kenya.

  1. David
    July 22, 2014 at 3:02 pm

    Thank you Francis. This is very helpful. How does this compare with using EPS wall panels instead of stones?

  2. July 23, 2014 at 5:47 am

    @david, eps sandwitch panels costs around kes 2k per m2, which is doudle the cost of masonry walling.

  3. Elizabeth Muthama
    August 17, 2014 at 3:01 pm

    Dear Francis
    Thanks alot for your informative articles,am a frequent leader since am interested with more information regarding construction.Am planning to build a four bedroom mainsonnette in kitengela but am confused by different opinions that i have gotten from several people on the breakdown.Kindly give me an estimate ,without finishes on the cost of the project

  4. Fred
    August 21, 2014 at 7:36 am

    Hi Francis,
    This article is very informative. Continue with the good work.

  5. Tonny Kiiru
    October 15, 2014 at 3:49 pm

    Evng Franc,
    Thanks for the quantity costings.
    0721 499 963.

  6. Joe
    June 1, 2016 at 4:37 pm

    Good work for first time home builders like me. I do really appreciate your work. Thumbs up!!!

  7. zehra
    June 10, 2016 at 4:32 pm

    How many cement bags do I need to cover a wall extension using 90stones. How many cemebt bags will I need to make a final smooth plaster.

  8. Viwe
    February 9, 2017 at 6:53 pm

    No 1bag of cement mix with 3 wheel burrow of sand / this thing of 1 bag of cement mix with 4 wheel burrow sand is old news.

  9. Mike
    April 21, 2017 at 4:07 pm

    Very useful. Thanks

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