Design and Estimation works for residential and commercial buildings is very common and easy practice as we are well known to its design parameters and practices in field. Difficulties arise when new challenges arise in front of us where completely new kind of structures are to be disigned, Valuated and even Supervised for construction. One of such challenges is “Old-school” brick kilns which are neither taught academically nor practiced often for design ,construction and estimation. Luckily, I got a chance to work with a team experienced with design and valuation of such kinds of brick kilns. So, for the account I’ve decided to record it’s technicalities for my blog.
Draught Zig Zag kilns are very widely used in south East Asia, mainly in the Brick industries where Local materials can be used with very minimum investment to construct an efficient and strong kiln structure which is very easy to operate manually without the involvement of much manpower and resources for its operation. International Centre for Integrated Mountain Development (ICIMOD) along with other organizations like Federation of Nepal Brick Industries , Climate and Clean Air Coalition (CCAC) etc prepared a guideline for Design of such structures in 2015 that helped in construction of Structurally Safe, earthquake-resistant, energy efficient, lower emitting, worker-friendly for producing better quality bricks. We’ll be using same guidelines for the Drawings and Estimation works for the Brick kilns. While site considerations , materials, Methodologies and Specifications can easily be extracted from the ICIMOD website, we’ll focus on different strcutural components, their functions, Designs and cost Estimate parts in this article.
Structures:
Mainly, the major functioning structures that can be found in these kind of kilns can be divided into three Parts, Namely:
- Outer Wall
- Miyan
- Chimney
As their name suggests, Outer walls are the outermost part of the kiln and Miyan are the Structures which acts as the guides/Paths for the flow of heat produced from the chimney towards the raw bricks kept in between Miyan and Outer walls. Different ducts are constructed within the Miyan and a metal Box arrangement is used to direct the flow of heat towards the desired location where raw bricks are kept for baking using the kiln. Thus produced bricks are then transported using trucks which inters the area through wicket Gates constructed in the outer walls for the accessibility.
Drawing and Estimation:
Outer wall:
Brick work in mud mortar in outer wall
• All brick works can be in mud mortar.
• The outer wall is basically is a double wall structure with cavity in between. Refer drawing for details and dimensions.
• Brick work of foundation will start with 4 brick thickness and will continue up to 2’6” height.
• The internal cavity should be filled with rabis or silt or any type of soil with good insulation properties with proper compaction.
• The linking walls of 14 inch thickness should be constructed at the interval of 5 feet distance.
• The 2nd class brick can be used for the wall construction.
• The broken brick together with full sized bricks can be used in the masonry below ground level.
Quantity Estimation for Outer walls:
A field data quite similar to drawings has been used in the estimation sheet, please contact me in case of any confusion:
| Outer Walls | ||||||||
| SN | Description | No. | Length | Breadth | Height | Quantity | Unit | Remarks |
| 1 | Site Clearance | 1 | 2,208.48 | sq.m | Lumpsum icluding inside | |||
| 2 | Earthwork | 1 | 240 | 1.25 | 0.9 | 270.00 | cu.m | |
| 3 | Brickworks | |||||||
| Brick Works on outer walls with 3rd class Brick Masonry with Mud Mortar | 1 | 240 | 0.9 | 3.65 | 788.40 | cu.m | ||
| Deductions ( Gates) | ||||||||
| Big Opening | -1 | 3.6 | 0.9 | 3.65 | -11.83 | cu.m | ||
| Small Opening | -11 | 1.89 | 0.9 | 3.65 | -68.30 | cu.m | ||
| Total Brickworks with 3rd Class Brick Masonry with mud mortar | 708.28 | cu.m |
Miyan:
Brick work in mud mortar in Miyan wall
• All brick works can be in mud mortar.
• Brick work of Miyan foundation starts with thickness of 6 bricks at the bottom which gradually decreases and ends with thickness of 2 bricks wall at the top.
• The masonry wall is provided with various thicknesses at various heights. (refer drawings )
• The cross wall links the either sides of Miyan wall. The inlet holes in the cross wall which connects side nali with main nali through shunt system. The thickness of cross wall is 18 inches. Refer drawing for more detail.
• The 2nd class brick can be used for the wall construction.
• The broken brick together with full sized bricks can be used in the masonry below ground level
Chimney:
Foundation work for Chimney
Sand filling
• A layer of sand should be filled on excavated chimney foundation
• The thickness of sand layer should be at leat 1’-0”.
• The sand layer should be gently compacted and be leveled properly
Brick Soling
• A single layer of flat brick soling should be provided on top of sand layer.
• The joint of brick soling must be completely filled with proper sprinkling of water.
Plain Cement Concrete
• A thickness of PCC layer should be at least 4 inches.
• The mix ratio of concrete should be at least 1:3:6 i.e. one cement, three sand and six aggregate
• Before laying concrete, the brick soling must be completely soaked with water.
• The mixing of concrete must be mechanical mixing using mixer machines.
• By any case if it is not possible to bring mixture machines then it is strongly recommended to execute hand mixing properly with three times dry mixing and three times wet mixing.
• The concrete must be cured for at least 7 days.
Concrete Works in Foundation:
Reinforced cement concrete (RCC) work
Raft Foundation
• The minimum grade of concrete is M20 for raft.
• The mix ratio of concrete is at least 1:1.5:3 of cement: sand: aggregate to achieve concrete grade of M20.
• The steel grade is Fe415.
• The thickness of raft foundation is at least 1’6’’.
• There are two layer of reinforcement in the raft footing; i. Bottom layer and ii. Top layer.
• Bottom layer reinforcement is provided by 16 mm Φ (diameter) bars laid @ 6” center to center at both ways. Similarly, top layer reinforcement is provided by 12 mm Φ bars laid @ 6” center to center at both ways.
• Sufficient number of chairs should be provided to maintain the uniform gap between top and bottom reinforcement layers.
• The minimum thickness of clear cover should be 50 mm in all sides of raft.
• The ductility detailing must be strictly followed.
• The curing of RCC work must be done at least for 21 days.
• All other details should be as per the specification and drawings provided.
• The presence of site engineer/ technical personal is mandatory in whole process of raft foundation works.
Superstructure :
Reinforced cement concrete (RCC) work
Chimney
• The minimum grade of concrete is M20 .
• The mix ratio of concrete is at least 1:1.5:3 of cement: sand: aggregate to achieve concrete grade of M20.
• The steel grade is Fe415.• The ductility detailing must be strictly followed.
• The curing of RCC work must be done at least for 21 days.
• All other details should be as per the specification and drawings provided.
• The presence of site engineer/ technical personal is mandatory in whole process of raft foundation works.
Quantity Estimation for Miyan and Chimney:
| Miyan and Chimney | ||||||||
| SN | Description | No. | Length | Breadth | Height | Quantity | Unit | Remarks |
| 1 | Site Clearance | 1 | 2,304.00 | sq.m | Lumpsum | |||
| 2 | Earthwork | |||||||
| Excavation | ||||||||
| For Chimney | 1 | 14.2 | 1.35 | 2.74 | 52.53 | |||
| For Miyana | 0.00 | |||||||
| Outer Walls | 1 | 170 | 0.9 | 0.9 | 137.70 | |||
| Inner Walls for flue duct | 24 | 5.58 | 0.9 | 0.9 | 108.48 | Walls on both Sides of Flue duct | ||
| Inner Walls for flue duct at ends | 4 | 3.2 | 0.9 | 0.9 | 10.37 | |||
| Total Earth Works in Excavation | 309.07 | |||||||
| Filling | 1 | 83.4 | 5.58 | 2.84 | 1,321.66 | |||
| deductions | ||||||||
| Outer walls Deduction | -1 | 170 | 0.6 | 2.84 | -289.68 | |||
| inner walls for flue duct | -24 | 5.58 | 0.6 | 2.84 | -228.20 | |||
| inner walls for flue duct at ends | -4 | 3.2 | 0.6 | 2.84 | -21.81 | |||
| Chimney | -1 | 16.04 | 2.84 | -45.55 | ||||
| Total Earth Works in Filling | 736.41 | |||||||
| 3 | Brickworks | |||||||
| For Miyana | ||||||||
| Outer walls | 1 | 170 | 0.6 | 3.66 | 373.32 | |||
| inner walls for flue duct | 24 | 5.58 | 0.6 | 3.66 | 294.08832 | |||
| inner walls for flue duct at ends | 4 | 3.2 | 0.6 | 3.66 | 28.1088 | |||
| Deductions | ||||||||
| Openings | -24 | 0.6 | 0.6 | 1.4 | -12.096 | |||
| Total Brick Works with Mud Mortar | 683.42112 | cu.m | ||||||
| For Chimney | ||||||||
| Above Miyana | 1 | 10.758 | 0.23 | 18.6 | 46.022724 | average length | ||
| Below Miyana upto Foundation | 1 | 14.288 | 0.23 | 2.75 | 9.03716 | |||
| Total Brick Works with Cement Mortar | 55.059884 | cu.m | ||||||
| 4 | PCC Works | |||||||
| For Chimney Foundation | 1 | 15.9 | 0.1 | 1.59 | ||||
| Total PCC Works | 1.59 | cu.m | ||||||
| 5 | RCC Works | |||||||
| For Chimney Raft | 1 | 15.9 | 0.2 | 3.18 | ||||
| For Rcc Bands | 9 | 10.758 | 0.33 | 0.1 | 3.195126 | Average Length | ||
| For Shear Wall of Chimney | ||||||||
| Above Miyana | 1 | 8.76 | 0.1 | 18.59 | 16.28484 | Average Length | ||
| Below Miyana upto GL | 1 | 12.44 | 0.43 | 2.74 | 14.656808 | |||
| Foundation Shear Wall | 1 | 12.44 | 0.43 | 2.236 | 11.9608112 | |||
| Total RCC Works | 49.2775852 | cu.m | ||||||
| 6 | Reinforcement Works | |||||||
| Reinforcement for RCC Works | ||||||||
| Total Reinforcement Works | 5.80243566 | MT | Taking 1.5% of RCC Volume | |||||
| 7 | Hume Pipes Work | |||||||
| Hume pipe running between Chimney and Ducts | 1 | 81.4 | 81.4 | m | ||||
| Total Hume Pipe Works | 81.4 | m | ||||||
| 8 | Plaster Work | |||||||
| External Plaster on Chimney Structure | 1 | 14.199 | 18.59 | 263.95941 | sq.m | |||
| Total Plaster Works | 263.95941 | sq.m | ||||||
This is the Basic Outlook to how Zigzag Drought Kiln works and Detailed Estimation works can be done. Other Factors like Site Conditions, Material usage and Methodologies can be known in more detail by following the Guidelines by ICIMOD which can be assessed from here . Feel free to contact me in case of any confusion or any further interest on this subject matter or work of this kind.
Khatra dai.Ekdam dami josh Herdei ekdam mehnat xa.
Testo Mehenat ta Lagena.. Thank you tara! 😀
Well presented
Glad that it was clear !