Concrete Blocks or Bricks for Construction ?

[MNRS]

Hi All

Concrete Blocks (Solid as well as Hallow) or Bricks which is good for the Construction ?

Which one is having good insulation from the heat/cold weather ? And what is the thickness of the wall we should have it for a long life & other benefits ?

Can some one give pros & cons ?

Thanks

[MNRS]

Anyone can plz respond ?

[ardesarchitects]

Hi,Mnrs
Brick is always a best option for walls. The life time of a brick is far better than cement block. Brick has good properties of insulating heat and acoustics.
Since red bricks are made of natural mud/clay the chemical properties stay for life time, whereas cement blocks loses its chemical property in a couple of decades.
Once the cement loses its property, you face problems like moisture seepage (black fungus marks on the wall - frequently seen in old apartment external walls), biding capacity (a nail passes easily), cracks etc...
In a red brick only problem is in the joints of concrete beams and walls, proper care should be taken while plastering the joints. Plastering wire mess should be used in all the wall to concrete joints.
If you take regular care for external walls like painting, waterproofing a cement block can also give you a good life for the building.

Regards
Ar.Praveen.N
Ardes Architects and Interior designers
ardesarchitects@yahoo.co.in

Ar.Praveen,

[srinivas_palukuru]

Hi Praveen,

Thank you very much for the detailed explanation.

can you also let me know about the cost difference of both?

Regards,
Srinivas

[MNRS]

Hi Praveen

Thank you very much for the information.

Please also let us know the cost perspective.

Thanks

[MNRS]

Also what about the thickness of the wall if we use the concrete block or bricks ? What is the thickness for the internal walls & External walls can be used ?

[MNRS]

Here is the article from the Economic times. Please sure your views.

http://economictimes.indiatimes.com/fea ... 681429.cms

Low-cost housing is a low-caste relative
14 Mar 2010, 0543 hrs IST,Debasish Roy,ET Bureau
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Low Cost Housing is a new concept which deals with effective budgeting and following of techniques which help in reducing the cost construction

through the use of locally available materials along with improved skills and technology without sacrificing the strength, performance and life of the structure.

There is huge misconception that low cost housing is suitable for only sub standard works and they are constructed by utilizing cheap building materials of low quality. The fact is that Low cost housing is done by proper management of resources.Economy is also achieved by postponing finishing works or implementing them in phases.

Building Cost


The building construction cost can be divided into two parts namely:


Building material cost : 65 to 70 per cent, Labour cost : 65 to 70 per cent


Now in low cost housing, building material cost is less because we make use of the locally available materials and also the labour cost can be reduced by properly making the time schedule of our work. Cost of reduction is achieved by selection of more efficient material or by an improved design.

Areas from where cost can be reduced are:-


1 ) Reduce plinth area by using thinner wall concept .Ex.15 cms thick solid concrete block wall.


2) Use locally available material in an innovative form like soil cement blocks in place of burnt brick.


3) Use energy efficiency materials which consumes less energy like concrete block in place of burnt brick.


4) Use environmentally friendly materials which are substitute for conventional building components like use R.C.C. Door and window frames in place of wooden frames.


5) Preplan every component of a house and rationalize the design procedure for reducing the size of the component in the building.


6) By planning each and every component of a house the wastage of materials due to demolition of the unplanned component of the house can be avoided.


7) Each component of the house shall be checked whether if it's necessary, if it is not necessary, then that component should not be used.


Cost reduction through ad-hoc methods


Normally the foundation cost comes to about 10 to 15per cent of the total building and usually foundation depth of three to four feet is adopted for single or double store building and also the concrete bed of 6 inches(15 Cm) is used for the foundation which could be avoided.

It is recommended to adopt a foundation depth of 2 feet(0.6m) for normal soil like gravely soil, red soils etc., and use the uncoursed rubble masonry with the bond stones and good packing . Similarly the foundation width is rationalized to 2 feet(0.6m).To avoid cracks formation in foundation the masonry shall be thoroughly packed with cement mortar of 1:8 boulders and bond stones at regular intervals.

It is further suggested adopt arch foundation in ordinary soil for effecting reduction in construction cost up to 40per cent. This kind of foundation will help in bridging the loose pockets of soil which occurs along the foundation.

In the case black cotton and other soft soils it is recommend to use under ream pile foundation which saves about 20 to 25 per cent in cost over the conventional method of construction.

Plinth

It is suggested to adopt 1 feet height above ground level for the plinth and may be constructed with a cement mortar of 1:6. The plinth slab of 4 to 6 inches, which is normally adopted can be avoided and in its place brick on edge can be used for reducing the cost. By adopting this procedure the cost of plinth foundation can be reduced by about 35 to 50 per cent. It is necessary to take precaution of providing impervious blanket like concrete slabs or stone slabs all round the building for enabling to reduce erosion of soil and thereby avoiding exposure of foundation surface and crack formation.

Walling

Wall thickness of 6 to 9 inches is recommended for adoption in the construction of walls all-round the building and 41/2 inches for inside walls. It is suggested to use burnt bricks which are immersed in water for 24 hours and then shall be used for the walls

Rat - trap bond wall


It is a cavity wall construction with added advantage of thermal comfort and reduction in the quantity of bricks required for masonry work. By adopting this method of bonding of brick masonry compared to traditional English or Flemish bond masonry, it is possible to reduce in the material cost of bricks by 25 per cent and about 10 to 15 per cent in the masonry cost. By adopting rat-trap bond method one can create aesthetically pleasing wall surface and plastering can be avoided.

Concrete block walling


In view of high energy consumption by burnt brick it is suggested to use concrete block (block hollow and solid) which consumes about only 1/3 of the energy of the burnt bricks in its production . By using concrete block masonry the wall thickness can be reduced from 20 cms to 15 cm Concrete block masonry saves mortar consumption , speedy construction of wall resulting in higher output of labour, plastering can be avoided thereby an overall saving of 10 to 25 per cent can be achieved.

Soil cement block technology



It is an alternative method of construction of walls using soil cement blocks in place of burnt bricks masonry . It is an energy efficient method of construction where soil mixed with five per cent and above cement and pressed in hand operated machine and cured well and then used in the masonry . This masonry doesn't require plastering on both sides of the wall. The overall economy that could be achieved with the soil cement technology is about 15 to 20per cent compared to conventional method of construction .

Doors and windows


It is suggested not to use wood for doors and windows and in its place concrete or steel section frames shall be used for achieving saving in cost up to 30 to 40per cent.Similiarly for shutters commercially available block boards, fibre or wooden practical boards etc., shall be used for reducing the cost by about 25per cent.By adopting brick jelly work and precast components effective ventilation could be provided to the building and also the construction cost could be saved up to 50per cent over the window components .

Lintals and Chajjas


The traditional R.C.C. lintels which are costly can be replaced by brick arches for small spans and save construction cost up to 30 to 40per cent over the traditional method of construction. By adopting arches of different shapes a good architectural pleasing appearance can be given to the external wall surfaces of the brick masonry.

Roofing

Normally 5 inches(12.5 cms) thick R.C.C. slabs is used for roofing of residential buildings . By adopting rationally designed insitu construction practices like filler slab and precast elements the construction cost of roofing can be reduced by about 20 to 25per cent.

Filler slabs


They are normal RCC slabs where bottom half (tension) concrete portions are replaced by filler materials such as bricks, tiles, cellular concrete blocks, etc.These filler materials are so placed as not to compromise structural strength, result in replacing unwanted and nonfunctional tension concrete, thus resulting in economy. These are safe, sound and provide aesthetically pleasing pattern ceilings and also need no plaster.

For more on filler materials check Filler Materials Used in Concrete Jack arch roof/floor They are easy to construct, save on cement and steel, are more appropriate in hot climates. These can be constructed using compressed earth blocks also as alternative to bricks for further economy.

Ferrocement channel/shell unit


Provide an economic solution to RCC slab by providing 30 to 40per cent cost reduction on floor/roof unit over RCC slabs without compromising the strength. These being precast, construction is speedy, economical due to avoidance of shuttering and facilitate quality control.

Finishing Work


The cost of finishing items like sanitary, electricity, painting etc., varies depending upon the type and quality of products used in the building and its cost reduction is left to the individual choice and liking.

Conclusion

The above list of suggestion for reducing construction cost is of general nature and it varies depending upon the nature of the building to be constructed, budget of the owner, geographical location where the house is to be constructed, availability of the building material, good construction management practices etc.

However it is necessary that good planning and design methods shall be adopted by utilizing the services of an experienced engineer or an architect for supervising the work, thereby achieving overall cost effectiveness of the project to the extent of 25per cent in actual practice.

LOW COST AND LEAN


One of the important principles under a lean production paradigm is termed 'lean assembly' . This refers to simplifying the process of assembly through industrialisation, modularisations , standardisation , and continuous flow processes. The reduction of operations required for a production process means less chance of the occurrence of errors, waste and rework. This follows from the same logic that the fewer the number of operations, the higher the quality of the product and a predictive timeline, resulting in cost savings. Plastic concrete formwork system, for low cost housing, provides and assists with the full range of requirements involved in the transfer and use of a proven low construction cost housing technology . Some vendors supply housing technology and support transfer of know-how to empower individuals to achieve worth, by meaningful action to raise those at the "bottom of the pyramid" to a higher level, supplying low cost housing technology.

[ardesarchitects]

Hi Mnrs,
external walls should be min 8' for concrete block and 9" for brick.In a framed structure walls has nothing to do with any load transfer.Its mainly for water proof,temp control and safety .
All internal walls be just 4" in concrete and 4.5" in brick, again internal walls has noting to do with load .A 4.5" is sufficient to run all service lines like plumbing, electrical etc.......

For all these low cost methods as mentioned a proper planning is required and the major problem is with contractors denying to work for reasons like

1. strength of the building will be less
2. More manual power required
3. Their profit margins will be less
4. Time taking methods
5. Lack of experience in executing etc......................
The savings achieved by using above methods are directly passed on to the owner only if he works a proper detailed contract with the contractor.
You should either opt for item wise contract or labor contract to enjoy at least 80% of your savings. In lump sum sft base contract you should be very calculative, give all the details to the contractor (steel details, lintel details, wall details etc.....) and pre negotiate per sft .
Regards
Ar.Praveen.N
Ardes Architects and Interior Designers
ardesarchitects@yahoo.co.in

[MNRS]

Thx Praveen for the info. Really appreciated your time to respond to so many queries.