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Making Hollow Blocks from Farm Wastes

By Pinoy Farmer | February 7, 2008
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Rural folks can beat the high prices of housing materials. Out of farm waster and ordinary soil, one can make durable hollow blocks comparable in strength to commercial ones.

The hollow blocks can be made right on the building site and fashioned similar to commercial hollow blocks. Although considered strictly non-load bearing, it is very satisfactory for low cost housing. Its compressive strength ranges from 197 to 386 pounds per square inch (psi).

This simple technology, developed by the Forest Product Research and Industries development Commission, makes use of a minimum amount of cement to make a stronger hollow block. One bag is enough to make 20 four-inch blocks or 12 six-inch blocks.

The first step is to gather agri-wood waste such as sawdust, coconut trunk particles, sugar cane bagasse or ordinary soil. The latter has to be pulverized and sifted using a 1/4 inch wire mesh. Abaca waste, left after extracting fiber from the stalk, as well as coconut coir dust, the residue from processing coconut husk in coirflex plants, can also be used. Rice hull works too, but additional soil is needed when mixing this with the cement.

Improvise hand mold to shape the hallow block. This can be made out of steel or wood of relatively high density such as apitong, guijo or yakal. The mold should have three removable core blocks, and the sides should easily be opened and secured. Place hinges and lockpins as illustrated.

Using the cubic foot measuring box, mix together one box of cement and three boxes of agriwaste, or the equivalent proportions. With the materials form a hill with a crater on the top. Pour water slowly, then, thoroughly mix them with shovel until the paste is formed. The mixture must be neither too dry or too wet such that they would stay packed when molded and when not spread out when removed from the mold.

Place the flatboard at the bottom of the hand mold, then fill it with the mixture. Tamp and level off extra paste, then place another flatboard on the top. Turn the mold upside down, and tamp and level off as before.

After a while, remove the three core blocks and the pin to let the sides open. Gently push the molded hollow block from the mold, leaving it in place on the flatboard.

Place the hollow blocks in a shade for a few hours to dry. after one side has dried, turn the block upside down to dry the other side. Store these lock standing on their narrow edges.

For about ten days, cure them by occasional sprinkling water over the blocks. Afterwards, they are ready for use.



1. Carbonize the rice hulls.
2. Pulverize the ash.
3. Mix the following: 60 parts cement, 40 parts carbonized ashwater
4. Pour the mixture into wooden molds
5. Allow to dry.


A new type of hollow blocks can be fabricated out of wood wastes, agricultural wastes and soil mixed with minimum amount of cement. As far as strength and durability are concerned, results of test showed that this type of blocks is comparable to some of the commercial or traditional concrete hollow blocks. However, they are considered as strictly non-loading bearing.


1 part cement + 3 parts sawdust, ordinary soil, rice hulls, abaca waste, sugarcane bagasse, coconut coir dust and coconut trunk.


1. Pulverized soil is passed through a wire screen, 1/4 inch wire mesh to separate larger pieces. A mixture of 1 part cement to 3 parts agri-waste is formulated.
2. Mix all materials together, add water and pour into molds.
3. Let stand for several hours until dry.
4. After drying, remove from molds and let stand along one side for 10 days while sprinkling water at regular intervals to avoid cracking.

source: http://www.dost.gov.ph

Topics: How to, Technologies | 21 Comments »

21 Responses to “Making Hollow Blocks from Farm Wastes”

  1. Agriculture.ph Blog » Ricehull Ash Cement Hollow Blocks Says:
    January 13th, 2009 at 12:09 pm

    [...] Making Hollow Blocks from Farm Wastes -> http://www.agripinoy.net/making-hollow-blocks-from-farm-wastes.html [...]

  2. ana Says:
    March 23rd, 2009 at 7:30 pm

    i read an article on the internet featuring something about turning farm wastes into hallow blocks. i want to use this as a topic for our investigatory project as a requirement for our subject in science, technology and society. i hope you can allow me to conduct an interview with the people concerned on that project. i hope you can reply as soon as possible because we will be submitting this on coming monday.. thank you so much!!!

  3. cristina Says:
    March 27th, 2009 at 12:57 pm

    your project was very interesting. i am an agricultural engineering gradaute..
    this is a better alternative for the commercial hollowblock..
    more power… Godbless…

  4. celso opaco Says:
    May 13th, 2009 at 7:22 pm

    The above methods on hollow block making are really very encouraging. I would just like to ask if it is also feasible to use seagrass as this is very plentiful especially in coastal areas like in Bohol where I come from. If it is, what method would best apply to its production? Thank you for your advice.

  5. kath Says:
    July 6th, 2009 at 7:28 am

    hello!! i have also read that using animal manure can also be a substitute for making hollow blocks.. i am doing a study right now and i just want to know if you are producing hollow blocks from farm waste.. cause if you are, i will only have to study its profitability in the market and if you’re not ill have to know the cost of production and if it is marketable..hope you’ll reply…More Powers and God Speed!!

  6. richtz Says:
    July 20th, 2009 at 4:36 pm

    your article is GOOD!,thanks for some infos that i’ve got….may i ask that, iS iT possible making hollowed blocks using chicken’s or other flying bird’s feather as main ingredient in making hollowed blocks??…..pLS answer my qurstion….help me to my research…

  7. richtz Says:
    July 20th, 2009 at 4:38 pm

    i need your answer mr. agriculturists asap on my yahoo mail……

  8. Kathy Says:
    September 3rd, 2009 at 2:21 pm

    I was searching for a good method in making hallow blocks….for my investigatory project,and i found out that agri wastes can be used.

  9. Gossips Says:
    September 13th, 2009 at 5:19 am


    Any videos on how to do it, especially the one method METHOD #2 – RICE HULLS?

    It would be highly appreciated. Thanks

  10. novie Says:
    December 2nd, 2009 at 6:23 pm

    i have learned that a lot of low- cost materials are now being used as substitute to aggregates in making hollow blocks, and crushed glass bottles where used by my co-student in our university as a substitute and as a result, it was successful for it enable to carry the weight of one of our instructor. also, the hollow block was light-weight. still it has not been exposed to different weather situation, not until me classmates would make a continuation of the research. now my question is, are coconut palm shells a good substitute for aggregates? do you think it would sustain in weather changes? these will be used in my research project. thanks a lot.

  11. jestalin Says:
    July 2nd, 2010 at 8:22 pm

    hi there, im doing an feasibility study now.. for my subject, it is requirement for us to graduaut. i would like to know about the materials in producing hollow blocks, technical aspect, marketing aspect and the financial aspect.. i hope you can help me. thankss andGod bless..

  12. vincent mabida Says:
    August 24th, 2010 at 3:57 pm


    I am working on an invetigatory project about improving the durability of hollowblocks.
    Can i use plastic instead of agri waste..?
    hope can you reply as soon as possible…
    thanks a lot

  13. rodrigo quimbo Says:
    August 24th, 2010 at 4:12 pm

    tabangi ko sa ako project!!….

  14. shee Says:
    September 5th, 2010 at 5:07 pm

    we made a research on using waste materials as a substitute or ingredient in hollow blocks, we chose the rice hulls..are there limitations of burning the rice hulls?..

  15. jbs Says:
    September 30th, 2010 at 7:24 am

    A very inspiring breakthrough in the field of construction… I will recommend to use it.

    God Blessed


  16. Debbie Says:
    April 17th, 2011 at 8:14 am

    Can you kindly send me more information on how to make the hollow blocks making for fine..

    Thank you.

  17. ma. carmela Says:
    July 17th, 2011 at 9:14 am

    Ammmmmmmm! that’s good. I like it!

  18. chingster Says:
    August 11th, 2011 at 12:53 pm

    huhuh can somebody help for our study about baggase ash as additives to concrete hollow block.. pm me here…

  19. parahansis Says:
    August 12th, 2011 at 2:19 am

    haha! its good! thanks 4 d informations! Godbless!

  20. welen Says:
    August 27th, 2011 at 1:48 pm

    can you send me more info about your topic
    thank you…..

  21. ruby Says:
    September 11th, 2011 at 4:18 pm

    good day im a 5th year student im looking for a good topic for our thesis, and i found your work so interesting, can i modify your work for our research proposal? im hoping for your approval.. thanks ;)