Which cement is best for a slab?

A 42.5 grade. Bamburi Nguvu, Bamburi Powermax and Simba 42.5N are all 42.5. For structural concrete the grade matters and the brand is largely preference: 42.5 develops higher strength and develops it faster, which is what a slab, a column or a beam needs.

Can I use 32.5 cement for concrete?

For non-structural concrete, yes. For anything carrying load, use 42.5. The saving on a slab is roughly 75 shillings a bag, which on a typical residential slab is a few thousand shillings against a structure that has to stand for decades. It is the wrong place to economise.

Why is Powermax nearly double the price of Fundi?

Different products. Fundi is a 32.5 masonry cement for mortar, plaster and screed. Powermax is a 42.5 structural cement with much higher early strength. They are not substitutes and comparing their prices directly is comparing two different materials.

Does buying by the tonne save money?

Usually yes, and the saving is real on a large order because you are cutting out a layer of margin. Wholesale rates sit meaningfully below the retail figures above. Set against that, cement has a shelf life of roughly three months and absorbs moisture from the air, so buying more than you will use inside that window converts a discount into waste.

Cement Prices in Kenya: What a 50kg Bag Costs, and Which Grade You Need

A 50kg bag of cement costs KES 735 to 1,350 in Nairobi: the 32.5 grades for masonry and plaster run 735 to 800, and the 42.5 grades for structural concrete run 855 to 1,350.

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What cement costs in Kenya right now

Prices below are for a 50kg bag in Nairobi, reviewed August 2026. Rates vary by region and by quantity, and wholesale sits meaningfully below these figures on a large order.

The number that matters is not the brand. It is the grade, printed on every bag.

32.5 against 42.5: the split that actually matters

Kenyan cement comes in two strength classes and they are for different jobs.

32.5 is masonry cement. Mortar for blockwork, plaster, render and screed. It is the majority of what is sold in Kenya because the majority of cement used in Kenya goes into blockwork and plaster.

42.5 is structural cement. It reaches higher strength and reaches it faster, which is what concrete carrying load requires: slabs, columns, beams, foundations.

Using 32.5 in structural concrete is the most common cement error on Kenyan sites, and it is invisible. The concrete looks identical. It sets, the formwork comes off, the building goes up, and the structure carries less than the engineer specified for the rest of its life.

What this means when you compare quotes

A quotation that says “cement” without a grade is not comparable to one that does. When you see a concrete or blockwork rate that undercuts the market noticeably, the grade of cement is one of the three places the money usually came from. The other two are the ballast and the water.

Shelf life

Cement is not a material to stockpile. It absorbs moisture from the air and loses strength doing so, and roughly three months is as far as you should plan. In the long rains, less. Bags stored on a bare floor draw moisture from the slab, so keep them on timber and sheeted.

If a bag has hard lumps that will not crush between your fingers, it has taken up moisture. It is not a bargain at any price for structural work.

Rates

Work	Rate	Notes
Simba 32.5R	KES 735	Masonry, plaster, screed
Rhino 32.5	KES 750	Masonry, plaster, screed
Bamburi Fundi 32.5	KES 780	Masonry, plaster, screed
Bamburi Tembo 32.5	KES 800	Masonry, plaster, screed
Bamburi Nguvu 42.5	KES 855	Structural concrete. The grade to insist on for slabs and columns
Simba 42.5N	KES 1,200	Structural concrete, higher early strength
Bamburi Powermax 42.5	KES 1,350	Structural concrete, fastest strength gain

Indicative market ranges for Kenya, reviewed August 2026, published so you can budget and compare quotes. They are not a quotation: your price is confirmed in writing after we have seen the job.