In this post we are going to look at
1.)About Ndarugo stone mine
2.)Location To Ndarugo
3.)Ndarugo stone size and dimension in mm
4.)Ndarugo stone and transport services
5.)Cost of a Lorry carrying Ndarugo stones
6.)Mutonga Stones
7.)More on Ndarugo stones
8.)Fake Ndarugo stones
9.)Ndarugo country homes
10.)Quality Ndarugo Mchine cut stones FAQ
11.)Challenges for Ndarugo stones
12.)Types of Machines for cutting stones
13.)List of Construction Suppliers and Construction Materials
Image of a lorry filled with stones at Ndarugo ,Juja
Ndarugo Stone Mines is a location in Kiambu county Juja that is vast in stone harvesting and deals mostly with Machine cut stones .Thus the term Ndarugo stones get to have their name from their origin place Ndarugo .
Image of an isuzu direct injection with ndarugo 9 by 9 stones
There are two types of Ndarugo stones Machine cut stone and Manual cut stones. Machine cut stones vary in terms of grading as there are Grade 1 2 and 3 .Quality Ndarugo Machine cut stones come in varieties of colors blue ,white ,khaki and dark grey
Image of Ndarugo stone mines
Image of Ndarugo stone mine strata
Along Thika super highway just past Juja ensure you are on the service lane and after passing exit A12 you can pass the under ground tunnel at Mangu then head over as going back to Nairobi and you will branch to your left and enter Ndarugo .Ndarugo is located in Juja you can also pass through Juja farm to get to Ndarugo.
Image of a Lecomett stone cutter at Ndarugo stone mines
Ndarugo Stones come with the length of 400mm and depth of 200mm.
The only difference with the three sizes is the width of the stone, the height and length are constant .
4” x 9” Inches (200mm*100mm*400mm)
6” x 9” Inches (200mm*150mm*400mm)
9” x 9” Inches (200mm*200mm*400mm)
At the quarry, all different stones above are priced the same as long as they come from the same strutter.
The cost of a lorry carrying Ndarugo stones depends if it is a tipper ,an Isuzu direct Injection or a highsided trailer
Image of Ndarugo stones felled at a site
For a TATA tipper 2516(25 tonnes,16 Horse power engine, the truck Carries 1000pcs of 6*9 ndarugo stones(@25 per piece)
Image of a TATA tipper truck falling Ndarugo stone
For 1000pcs ×25=25,000 cost is 25,000 Kenya shillings
Image of a Bhachu tipping trailer with Ndarugo stones
For a Mercedes Actross 3340 (33 tones,40 Horse power engine pulling a Bhachu Tipping Trailer, the truck carries 1800pcs, while each stone costing 25 Ksh
A Bhachu Tipping Trailer offloading machine cut stones
Total cost for a Bhachu Tipping Trailer full of Ndarugo stones equals 1800pcs ×25=45,000
An Isuzu Direct Injection offloading Machine cut stones
If its an ISUZU direct Injection, the number of Size 9*9 ndarugo stones will be 700pieces. multiplies by 30 ksh which is the cost =21,000Ksh
Image of Ndarugo Quarry stones
Mathematics behind Ndarugo Stones
Ndarugo 9by 9 stones ready for construction
instance 1
4 Bedroom House | 3500 pieces 9 by 6 |
3 Bedroom House | 2,500-2700 pieces 9 by 6 |
2 Bedroom House | 1,800 pieces 9 by 6 |
1 Bedroom House | 1,100 -1200 pieces 9 by 6 |
How many stones can build a perimeter wall of 40×80
Image of Kei apple fence along Ndarugo perimeter wall at Muthaiga North
Instance 2
For example (40+80)+(40+80)=240fts.Then we assume the height of your perimeter wall will be 10 courses
240fts×10=2400fts,since 1piece of ndarugo stone is 1.3feets,so it will be 2400feets÷1.3=1846.15pieces
Which means you will require approximately 1846pcs for your perimeter wall, Consider gate & pillars, so with 1800pcs of Ndarugo stones you have your wall done
Amount of stones required for erecting a perimeter wall for a 100 by 100 plot
Foundation stones:
To calculate the amount of foundation stones needed, you will need to find the perimeter of the plot. In this case, it would be:
100+100+100+100 = 400 feet
Assuming you want to lay 3 courses of foundation stones, you will need:
400 feet x 3 = 1200 feet of foundation stones
Walling stones:
To calculate the amount of walling stones needed, you will again need to find the perimeter of the plot:
100+100+100+100 = 400 feet
Assuming you want the wall to be 10 courses high, you will need:
400 feet x 10 = 4000 feet of walling stones
To determine the number of machine-cut stones needed, you will need to divide the total length of walling stones by the length of one machine cut stone which is 1.3 feet. Then:
4000 feet ÷ 1.3 feet = 3076 machine-cut stones
You may need to subtract a certain number of stones to account for the gate and columns, depending on the design of your fence and wall.
So, for a 100x100 plot, you would need approximately 1200 feet of foundation stones and 3076 machine-cut stones (minus the amount needed for the gate and columns,let's say 200pcs) for a 10-course perimeter wall.
The thickness of a wall; 6'' stone and plaster is 175mm with plaster on one surface of a wall.
This price list includes prices of 6 by 9 Ndarugo Stones inclusive of Transport to Location, however the pricing may change slightly due to high cost of fuel and living thus an increase of 5Ksh-15Ksh is expected
35Ksh | |
Ndarugo to Juja | 35Ksh |
40Ksh | |
Ndarugo to Muranga | 48Ksh |
Ndarugo to Utawala | 45Ksh |
50Ksh | |
Ndarugo to Nyeri | 50Ksh |
50Ksh | |
Ndarugo to Karatina | 58Ksh |
50Ksh | |
Ndarugo to Machakos | 50Ksh |
Ndarugo to Nanyuki | 55Ksh |
55Ksh | |
Ndarugo to Narok | 60Ksh |
67Ksh | |
Ndarugo to Naivasha | 55Ksh |
65Ksh | |
Ndarugo to Nyahururu | 65Ksh |
Ndarugo to Mombasa | 70Ksh |
72Ksh | |
Ndarugo to Keruka | 75Ksh |
75Ksh | |
Ndarugo to Nyamira | 75Ksh |
Ndarugo to Rongo | 78Ksh |
78Ksh | |
Ndarugo to Awendo | 78Ksh |
78Ksh | |
Ndarugo to Luanda | 85Ksh |
85Ksh | |
Ndarugo to Bungoma | 90Ksh |
Some machine cut stones finish is not smooth, this does not mean it's of poor quality, the reason could be attributed to gauge setting at quarry. When these stones are being split into desired sizes, there happen errors that results to sizes not being truly the same.
An image of a TATA tipper at Ndarugo Quarry Mine
This makes the stones to be uneven and hence the finish will not be smooth. Nonetheless, it does not mean that the quality of stone is not good.
Mutonga Stones
In Meru most of the building stones come from a place well known as Mutonga.This is the main large quarry that supply building stone to Meru
More on Ndarugo Stones
Since the introduction of Ndarugo Machine Cut stones, building construction industry has had numerous projects coming up.
The stones are easy to work on meaning high production of masonry work.There has also been a tremendous cost reduction in other materials
Like cement and sand which translates to cost effectiveness. The speed of work is also realized because in a day, a mason can lay up to 150 pieces
Which equates to 200 feet. However ,Mason's out-put can significantly get affected by prevailing weather conditions and height of the walls under construction
where safety cautions are Paramount. When a mason is working above six courses, work difficulty sets in because they require raised working platforms
where the number of pieces a mason can lay in such a condition can reduce to around 135 in number (180ft).With these figures that a mason can manage in a day.
You need to consider a few things to know the scope of work and the number of workers you require.
The number of Ndarugo pieces a lorry delivered to the site
The number of lorries delivered.
Remember that different lorries have different capacities and therefore for ease of doing things, try to have lorries that holds same loading.
An isuzu direct Injection at Marurui transporting Manual cut stones
Taking a physical count of number of pieces in a lorry is recommended. If the lorries have same capacities, multiply the number in each by total lorries received.
Once you know the total number of stones at the site. Divide the total by the number of stones a mason can lay in a day.
This helps in scheduling your work and for budgetary purposes that you cannot ignore.
Image of Ndarugo Grey stones
There are two cases with Fake Ndarugo stones ,either the broker sells you the Grade you did not intend as there are Grade 1 ,Grade 2 and Grade 3 stones .
There are several cases where the lengths of stones are reduced by up to 40mm.Please note that the length of stones should be 400mm which approximates 1.5 ft.
Going back to where we were about malpractices and implications to your final building cost.
Image of Ndarugo 9 by 9 stones
If a stone is supposed to have a length of 400mm but the cutter machine is adjusted to 360mm lengthwise,
The stones produced will be as per the cutter adjustment meaning that each stone bought will be less by 40mm
As customer of such building units you will be losing a stone in every 10 pieces you buy. In a case that you needed 1000 pieces,
A loss of 100 pieces will be incurred. Here is what happens if you are not keen to realize.
Around Nairobi a 200mm stone is delivered at around 50/= depending on quality. If a customers 1000 pieces had a short of 100pcs.The amount lost will be 100x50=5,000Sh.
The quality of stone is also a vital consideration. Apart from a sound structure, quality stones minimizes losses which affects your wallet immensely.
Imagine a situation where 10% load of stones will be wasted due to breakages during loading, delivery and off loading.
If a lorry had a load of 1000pcs where 10% will be waste you then lose 1000x0.1=100 pieces 100x50Sh.=5,000/=lost.
To avoid this, get a stone that is hard enough to withstand. One can visit a quarry to collect samples and approve the desired ones or the same can be requested from prospective suppliers.
Note that quality of stone improves as you move to the core. Different strutters have different nature of stones.
Stones from same quarry will have different qualities in strength and colour. A young quarry means uppermost strutter and stones are some how brittle.
Stone in these zones of quarry are considered poor and they are cheaper. The colour is also not distinct as those of in-depth strutters.
For uniformity of your external walls depending on your preffered finish.
Consider the element of colour of your stones for outer walls that could be finished by pointing also known as keying.
This is because stones of different themes will make your house appear to have patches which are not eye appealing.
IDENTIFYING THE NUMBER OF STONES YOU REQUIRE
To estimate the number of stones you need, begin by calculating area of walls of your building. These dimensions are clearly shown on architectural drawings.
Multiply the length by the height which is also indicated on section part of your drawings. Remember that widths of walls are illustrated on plan too.
Image of Ndarugo manual cut stones
Once you have total area to be constructed, get the area of openings like door ways, doors and windows and less from total area
First let's know number of stones in one m2.If area of one stone is 0.4x0.2=0.08 And the area taken by building mortar is 0.015 per m2
Then we say 1m2 less area taken by mortar 1-0.024=0.976.The Number of Ndarugo pieces in m2 is 0.985/0.08 =12.2 pieces
Factor 10% to cover for breakages/waste 12.312x0.1 =1.231
12.2+1.20 =13.4
Image of a perimeter wall at windsor done by manual cut stones
For Example If you have a wall of 20m and the height is 2.3 Then 20x2.3 =46m2
Assuming a wall has three openings as one door and two windows.Where a door area is 0.9x2.1 and each window has 1.2x1.5
Therefore the Door 0.9x2.1=1.89m2 and the Window. 1.2x1.5x2=3.60m2
Total for openings=5.49m2.Then Total wall- total openings 46m2-5.49m2 =40.51m2
Number of stones 40.51m2x13.4pieces =543.644pieces
Take 550 pieces
Quality Ndarugo Machine cut stones FAQ
How much is a ndarugo stone in Kenya?
Ndarugo Stone Size 9 X 9 cost at the quarry varies with color from Blue color costing Ksh 27.00 while Grey costing Ksh 30.00
Image of Ndarugo Machine cut stone
Ndarugo Stones come with the length of 400mm and depth of 200mm.The only difference with the three sizes is the width of the stone, the height and length are constant .
Ndarugo Stone Challenges
A post by Engineer Joseph Kimani
Whenever parging is done on these foundation stones with unwaterproofed plastering mortar, it becomes a futile effort. When unwaterproofed plaster for this 'mshipi' comes into contact with 'ndarugo' stones, it bypasses the moisture content over the DPC/DPM because the plaster itself will raise the ground moisture. It essentially creates another channel through which ground moisture can pass or rise.
Parging should always be done with waterproofed mortar because the plaster must cover the base stones, DPM, slab and DPS (damp-proof strips) and extend a few millimeters over the 'ndarugo' stones. Without waterproofing, this extension of the plaster directly connects ground moisture to the stones, undermining the structural purpose of the DPM/DPC/DPS.
You will then realize that, previously, when there was no plaster for this 'mshipi,' even though the foundation stones and joint mortar were wet due to ground moisture, the DPM/DPC effectively prevented moisture from rising to the slab concrete or 'ndarugo' stones. However, after applying unwaterproofed plaster, the problem emerged.
The most common signs of dampness on walls will be efflorescence, a crystalline deposit of soluble salts that can appear on the surface of concrete, brick or stone, leaving a white and powdery deposit. Additionally, the affected wall, whether external or internal, the applied paint may start blistering, peeling or flakeing.
Magisa
Image of a Magisa machine stone cutter
Magisa is an Italian company known to produce good quarry machines fit for limestone, sandstone, tufa, Vulcanic and Machine Cut Stones. There aredifferent types of the Magisa stone machine. Magisa has a wide range of model: from 100 to 220 Hp with different cut depths.
Big Electric Magisa 150 hp | Cut depth max. cm. 40 with circular blade | 10,670,608Ksh |
Small Electric Magisa 100hp | Cut depth max. cm. 40 with circular blade mm | 8,869,077Ksh |
Diesel Magisa 220hp | Cut depth max. cm. 42 with circular blade mm | 14,827,988Ksh |
Pavoni is an Italian company that produces machine cut stones,Available Pavoni machine includes
CAT Diesel Engine 225hp Liquid Cooled | Big vertical discs (5 1235 mm) with SS10 TIPS | 17,738,154Ksh |
CAT Diesel Engine 275hp Liquid Cooled | Big vertical discs (5 1235 mm) with SS10 TIPS | 18,015,313Ksh |
DEUTZ V8 Diesel Engine Air Cooled | Big vertical discs (5 1235 mm) with SS10 TIPS | 17,738,154Ksh |
DEUTZ Intercooler Diesel Engine Air Cooled | Big vertical discs (5 1235 mm) with SS10 TIPS | 16,629,519Ksh |
XGMA is a Chinese company , the XGMA machine cut stones useds electricity or a diesel engine as backup.
HKSS – 1400 75 Horse power | 5 Big blades.5 Small blades max. depth can cut is 500mm | 10,172,000Ksh |
LECOMET stone cutting machine is made in Italy. LE.CO.ME.T stands for LELLI COSTRUZIONI MECCANICHE. There are various types of the Lecomet machine
DEUTZ V8 Lecomet 300 Hp Machine | Consumption: 20 ltr/hr | 18,708,209Ksh |
VM V8 Lecomet 300 Hp Machine | Consumption: 20 ltr/hr | 18,569,630Ksh |
DEUTZ V6 Lecomet 200 Hp | 15,000 – 40,000 Pieces | 17,322,416Ksh |
Maca a family run business and still an Italian company that specializes in Machine cut stones. The electric engine is about 180 revolutions per minute and the horsepower varies from 150 to 220. The two available types of MACA are
DEUTZ V8 DIESEL Engine 180hp | 5 Big vertical discs with SS10 TIPS | 18153892Ksh |
Electric Machine 180hp | 5 Big vertical discs with SS10 TIPS | 17460995Ksh |
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