5) Cement Board Composters


Montreal is now discerning choices for developing a composting program.  Please add this Cement Board Rodent Proof Composter to your tool chest.  Clearly as we've established over decades of recycling programs, getting the odour (methane producing wet and smelly) materials separated in the urban and rural material-streams then valorises all other human material streams.  I helped establish Montreal island's first door to door 'Separation at Source' collection for the cities of Beaconsfield and Pierrefonds in the early 1980s.  When compostables are removed then all:  metals, plastics, paper, wood, electronics and even composites are rendered 'clean' and workable for handling, storage, repair, separation, rebuilding, or sale.  However as you know the circumstances and cultural habits of households are quite diverse so we need to design and implement multiple solutions.

CEMENT BOARD COMPOSTER at Home                        BOTTOM SOIL PORT Opened Vertically to shovel


It turns out public reluctance to join in composting is based in solid public health foundations, particularly the fear of rodents.  Urban planners must incorporate systems preferably on a modular locally implementable scale which enable individuals to recapture their resources locally, respect a diversity of interests or individual buy-in as well as a specialization of local tasks for devoted and hired experts.  See our on-line Human Resource Catalogue approach to animation along with a Community investment and Exchange System for local enterprise and livelihood.



This is to share with you a Rodent proof Cement Board Composter prototype unit we have begun using here in LaSalle-Gardens.  Attached are 12 Jpeg images 70 - 240  kb showing different aspects of the prototype.  Rodents such as rats, racoons, porcupine, skunks, groundhogs, moles and mice are the greatest fear impeding popular urban and rural composting.  On this basis Indigene Elemental Design has developed a low cost rodent proof composter prototype built of cement board.  We have worked with cement board in similar applications such as under roof drip lines with no sign of degradation over 30 years.  All edges of the 1Ž2 inch cement–board are wrapped with metal channels.  All corner / edge joins are made with 1Ž2 inch air gaps so as to fully aerate the composting mass.  All screw joints are made metal to metal with double metal such as on hinge surfaces where needed so as to provide strong resilience.  All 1Ž2 inch gaps are screened over so as to keep even small mice and their babies out.  Thus we join the strength and impermeability of cement board (same price as wood or plastics) with strong joints.

1/2 " SCREENING ON 1/2 " AIR GAP CORNERS            HINGES & HANDLES REINFORCED with Double Metal wrap


Each 2' x 2' x 4' modular unit holds over 16 cubic feet of compostable material.  Each unit is able to be attached with other modules or joined and expanded with other 2' x 2' x 4' units sharing a wall up to four units together (64 cubic feet) or contracted as needed and maintaining rodent impermeability.  The units are designed for 2 to 3 apartments each or typically a 6 door apartment backdoor area where 2 units back to back serve residents who may bring their compostables down to their service entrances.  A top access port over half the top 1' x 1' x 2' is hinged enabling householders to empty a compost pail.  The pail is best filled with kitchen sink water to continually wet down the mass as well as conveniently wash out the pail.  At the bottom of one side is a 2' x 1' x 1' hinged soil removal port which is securely latched on both sides.



Sand filled counterweight jug provides for easy cement-board top-lid opening with only a couple of ounces (tens of grams) of applied effort.  Top-Lid stays open held by jug while the householder is able to empty the household compost bucket into the rodent-free compost space.  Top-Lid is easily closed with a couple of ounces (tens of grams) effort and counterweight keeps the lid closed, when finished.


Presently the household compost bucket is typically filled with post wash dish water and then dumped wet into the composter.  We are hoping to join the prototype unit directly with a grey water drain from a nearby kitchen sink where appropriate bio-digradable soaps are used.  The warm fertile soapy water helps worms, bacteria and other crawling insects to thrive and decompose food and paper scraps within three months.  We have achieved these results consistently in both summer and winter (freezing and thawing are excellent decomposers although requiring one month more).


We expect the cement board composter to be part of a multiple option approach to composting with other evolving mechanisms also available over time.  The Cement Board Composter has both a short and a long term role to play in diverse circumstances as the whole system evolves.  For example anaerobic decomposition of fruit, vegetable and paper wastes is another option in specially designed flow through tubes for multiple families will generate methane gas at a rate 80 times that of fecal matter alone.  Fecal matter can combine with Fruit & vegetables in a closed loop continuous flow system to seed the needed bacteria for methane generation.  Urine separating toilet attachments as a 10$ plastic tray enable the capture of urine as a high-acid, non-pathogenic material which when diluted 1 to 7 parts water, may be used directly in high carbon leaf and other smell absorbing (100%) materials around trees, shrubs and other plants.  Developing energy security from our abundant methane sources including fuel for heating and other purposes can be achieved on a massive level decentralized across the Montreal island landscape without material transport loss and for greater local energy security and autonomy.  At the same time Montreal can develop the income and fuel worth in the range of many hundreds of millions of dollars a year while cleaning up our rivers, lakes, providing fertilizer for food growing and more.  When labour, transport dollars and energy are full-cost accounted, decentralized resource harvest systems properly designed clearly outcompete centralized collection and treatment systems.

Douglas Jack, coordonnateur, Sustainable Development Corporation,  Indigene Community, Jardins-LaSalle-Gardens Mutual Aid Committee, Maison de/Home of Dialogue, 9662 Jean-Milot, LaSalle-Montreal, Quebec H8R 1X9, Canada 514-365-9594 eco-montreal@mcgill.ca  douglasf.jack@gmail.com