Preventing blocked drains the earth friendly way

June 5th, 2013.

First published November 2006, last updated June 2013

An ounce of prevention is worth a pound of cure, or in this case – an ounce of enzyme is worth a pound of caustic soda; or a hundred bucks spent on a plumber.

I’ve lived in a few houses that aren’t on mains sewerage – they’ve either used septic systems or a blackwater recycling system. These types of systems need to be treated with extra care as (good) bacteria do the work of breaking down all the icky stuff.

A caustic soda (sodium hydroxide) based chemical for clearing drains in these scenarios is a sure-fire way to kill *all* the hard working bacteria in these systems. So, in that respect, yes, it’s an environmental hazard.

Even if you are on mains sewage, pouring Drano or a similar product down the sink isn’t exactly the best choice. For starters, it’s a hazard having it on the premises and it’s a very dangerous product to have anywhere near children. Secondly, caustic soda, while breaking down rapidly in the environment; also breaks down just about anything it touches. There are certainly more earth friendly options.

One alternative is to pour a scoop of baking soda mixed with half a cup of vinegar down the drain, and follow it quickly with boiling water.

The other alternative, what I use, is an enzyme/bacteria based preparation.

These are sold under various names and can be purchased in most hardware stores. Although they appear to be a little expensive, it’s the solution that keeps on working; only requiring an infrequent top up dose. What they do is to help establish colonies of *useful* bacteria in your drains and systems that feast on.. ummm.. well, if it’s organic they eat it basically ;).

The great thing about these preparations is that they are totally non-toxic to humans and the environment and they are very easy to use – no complicated mixtures, just pour and you’re done!

Tip: when using these types of preparations, it’s best to add them just as everyone in your family is heading to bed – if large amounts of water follow the preparation, it can wash away the bacteria before they’ve had time to get a foothold in your drains.

The next time you notice your drains smelling or perhaps water not getting away as quickly as it should, reach for bacteria instead of caustic soda. Bacteria, while sometimes our enemy, are quite often our friends!

Another couple of tips in the “prevention vs. cure” genre:

If you have a grease trap – check it regularly. I became a bit lazy and assumed my grease trap was still in good working order after a scrape 12 months prior. I had gone into an over-enthusiastic water saving mode which didn’t help and I had also slacked off on adding enzyme – with rather smelly and messy consequences.

Something else I’ve found very useful is a sink drain strainer – these trap food and debris before it winds up in your plumbing.


How Sewage Wastewater Is Treated
Sewer Fat – The Other Energy Source

Some Assembly Required

May 23rd, 2013.

If you’ve ever grown your own veggies, you’ve probably noticed they taste better. Some of that is because they do of course, but I suspect it’s also partly to do with the effort put into tending to them.

A similar effect has been noted with regard to flat pack furniture and other DIY construction; even of simple items.

Coined the “IKEA effect”, researchers have found people place a higher dollar value on something they have “built” themselves compared with the very same product assembled by someone else, even if their own attempt is greatly inferior.

You can read more about the IKEA effect here.

I’m not about to claim IKEA is saving the world – the company has its issues – but the flat pack concept itself is great, if somewhat frustrating at times. Aside from saving on space used to freight the products, which helps reduce transport related emissions; it connects us more to things and makes us think.

I’m a fairly intelligent sort of bloke in the areas of verbal and non-verbal reasoning; but when it comes to spatial reasoning; I’m average. In some ways, it’s been like getting through life with one leg shorter than the other.

It means putting together something like a flat pack object can be a little challenging. The mistakes I make are quite basic, really “duh” sort of things. It was truly an achievement for me to assemble a steel cupboard recently – and yes, I do tend to value these things more.

And this is where where environmental issues come into play.

Half the problem of humanity when it comes to the environment is we are not connected to what we consume. We might understand its cost – say $x a pound for bacon – but not fully appreciate its value; e.g. the resources that went into getting that bacon onto the plate and the sacrifice of an animal that may have been raised in less than ideal conditions.

Because their appears to be little effort in acquiring things (we forget the toil to make the money to buy stuff) and a lack of knowledge of its origins or construction, we’re prone to consuming more, repairing and maintaining less and throwing things away.

“Some assembly required” not only attaches our toil value to that object, but also gives us an opportunity to appreciate more how objects are made. I think it also helps to build confidence in doing more for ourselves.

Save energy, emissions and money with ceiling fans and roof turbines

July 21st, 2012.

(Originally published December 2008, last updated July 2012)

Heating and cooling are some of the most energy intensive applications in a home and also the most costly in terms of electricity, gas, oil or even wood consumed.
The cost isn’t just financial. All that energy has to come from somewhere and unless your house is supplied with green energy indirectly or has a substantial solar panel array; heating and cooling often has a substantial environmental impact in terms of greenhouse gas emissions via power generation.
Ceiling fans – summer and winter

While you may be familiar with using a ceiling fan during summer, have you considered using it in winter also?

As heat rises, most of the warmth you want is close to the ceiling during winter. A ceiling fan on a low speed can help push that heat down to where you are. Additionally, it can help reduce the instance of condensation on your windows.

During winter the fan will need to run clockwise, which is the opposite of the direction you want it running in summer. The reason for this is that as cold air is denser, running the ceiling fan clockwise draws that cold air up, pushing the warm air close to the ceiling aside, which then travels down the walls to a lower level of the room.

Using as little as a hundred watts, an ultra-efficient ceiling fan can shave up to 10% off your heating costs.

Ceiling fans really come into their own over summer though and work particularly well in dry areas. By moving the hot air around, it promotes evaporation of perspiration on your skin which has an cooling effect – making you feel up to 8 degrees cooler. Our bodies have very efficient cooling systems that we interfere with by wearing clothes. While it’s generally frowned upon to get around with your kit off, if you’re at home alone, who is going to know! Still, even clothed, you’ll reap some benefits in using a ceiling fan.

I’ve used fans in temperatures of over 42C (107F+) in a dry environment and while it was certainly warm, I didn’t even break a visible sweat. 

Ceiling fans can also be used in conjunction with evaporative air conditioners to further promote the air conditioner’s effectiveness; allowing you to set the thermostat lower – saving power and water.

So when shopping for a ceiling fan, ensure it has a clockwise/anti-clockwise feature so you’ll be able to use it all year!
Roof turbines – benefits all year round
Also known as whirligigs or spinaways, roof turbines are lightweight spinning vents that suck air out from your roof cavity. Waterproof and requiring no electricity, the roof turbine will start spinning in even the lightest breath of air and good quality turbines can also withstand hurricane type conditions.

During summer, the space between your ceiling and roof gets incredibly hot – up to 50 – 60 degrees Celsius (122F to 140F). Even if you have insulation in your roof area, some of this heat will still make its way into your living space.

A roof turbine is relatively easy to install – even I was able to do it – and that’s saying something. Let’s just say I’m like lightning with a hammer; I never strike twice in the same place :). 

A handyman project I somehow managed not to screw up!

The blast of hot air I felt when cutting a hole in the roof for the turbine was incredible – it was like opening a door to a furnace. Much of that heat is now being whisked away and the difference is certainly noticeable.
During winter, and especially if you have roof insulation, leaving the roof turbine vent open can help reduce moisture build-up in your roof area. 

Up to 12 litres (around 2.5 gallons) of moisture can accumulate in your roof space daily from bathrooms, laundries and kitchens.  A dry roof space not only helps protect timber frames, but your insulation as damp insulation is nowhere near as effective as when it’s dry.
Don’t skimp on a turbine, I’ve seen some cheap and nasty plastic versions around that simply won’t last the distance. A good quality turbine doesn’t cost the earth though – I paid under a hundred dollars for the model above which is made primarily from aluminium alloy, has a cyclone (hurricane) rating and a 10 year warranty.

As to how many you’ll need; as roof turbines vary so much in size and operation, this will vary – but each manufacturer usually includes a guide on the outside of the box.
So there you have it – summer and winter, ceiling fans and roof turbines can help cut your energy costs; and that means less greenhouse gas emissions and more dollars back into your pocket!

Medium Density Fiberboard (MDF) And The Environment

May 12th, 2012.

I was looking for some wood board for a project recently and MDF was an option. But gone are the days where I think “yep, that will do the job” and I just buy it – I decided to look into MDF’s environmental street cred.

What is Medium Density Fibreboard?

Medium-density fibreboard (MDF) is a wood panel product made up of wood fibers (rather than small chips used in particle board) that have been bound together by heat, pressure and resin binders.

The wood fiber used often comes from pine plantations, but just about any wood waste can be used in its manufacture, including paper.

Advantages of MDF

– Strong – nearly double the strength of particle board
– Denser than plywood
– Can be painted
– Can be drilled, screwed (using suitable fasteners) and easily sawn
– Much cheaper than “natural” wood
– A good insulator
– Sound-proofing attributes
– Fungus/mold resistant
– Flammable, but difficult to ignite
– Can be recycled

All this makes medium-density fiberboard sound like a dream product, but there is one major environmental issue – the binders.

MDF and formaldehyde

Like particle board and some plywood, the binders and resins used in MDF may contain formaldehyde; a known carcinogen. While I found some references stating lignin can be used as a binder (a naturally occurring substance found in plants), it still seems urea- formaldehyde based products rule the roost.

One of the big problems with formaldehyde is it’s a substance that keeps on giving. Products containing formaldehyde will continue to off-gas for years. It’s for this reason plus the fact MDF is also susceptible to moisture that it’s recommended medium-density fibreboard  should be sealed with paint. 

Painting MDF doesn’t solve the problem though – it just locks it away.

While MDF can be recycled, the processes for doing so are relatively new and recycling drop-off locations seem to be few and far between. The UK appears to be the leader in MDF recycling at this point in time. 

Landfill is still the most common final resting place for MDF; where chemicals will leach out over time, possibly contaminating groundwater.

Other toxic volatile organic compounds (VOCs) may also be off-gassed for a few months after manufacture.

On the (somewhat) brighter side; it seems MDF uses less in the way of binders than particle board.

As the levels of formaldehyde based binders will also vary between brands and grade, asking about off-gassing/binder and other potential environmental contaminants while at your local hardware store may be worthwhile. Two types of formaldehyde-free MDF I was able to find available in the USA are Medex and Medite II. 

Just to clarify, by “formaldehyde-free”, I mean in reference to binding agents – all wood has some level of naturally-occurring formaldehyde.

For low/no-VOC Medium-density fibreboard, be prepared to pay more for it; but it should still be cheaper than “natural” wood.


Recycled composite plastic lumber

Is Treated Timber Environmentally Friendly?

April 3rd, 2012.

A recent project had me looking at various types of treated timber. As you read on, you’ll getter better understanding of why I opted not to use any of the following for a raised garden bed application and purchased composite plastic timber made from recycled waste materials instead.

What is treated timber?

I don’t think there’s anything more beautiful than timber when it comes to construction materials. White ants (termites) share a similar passion, but theirs is more a culinary appreciation. While some wood is more termite resistant than others, it all eventually succumbs or is affected by other elements, such as moisture, heat, mold and fungi unless somehow protected.

Treated timber is simply wood that has had chemical and/or other processes applied in order to make it more resilient to all of the above threats.

While wood used in housing doesn’t have to be treated if a building is constructed properly, where wood touches the ground or is exposed to the elements; you’ll need some sort of treated product. Paint may not be enough as it only takes a small chip to provide a doorway for termites and moisture and paint has its own environmental issues.

Types of timber treatment

Unlike paint, the chemicals used in treated timber sink deep into the wood, offering superior protection. When looking at treated timber products, the following acronyms may not be mentioned. Often treated wood will just come under a brand name, so when shopping around, be sure to ask what the actual chemical treatment is.


This is a type of treated timber most of us would be familiar with. CCA is often applied to pine logs used in car park barriers, playground equipment and houses.

The preservation method is Copper Chrome Arsenate. Copper and arsenate are the insecticide/fungicide components. “Arsenate” is arsenic – a very toxic substance and a known human carcinogen. Chromium is used to fix the copper and arsenate in the wood. Chromium is a heavy metal and also a carcinogen. 

Copper compounds will bind to sediment or soil particles. Copper can negatively impact on micro-organism activity in soil and it can become concentrated in plants, which are then consumed by animals that suffer adverse health effects.

As with other forms of treated timber, the concern is the copper, arsenate and chromium can leach into soil over time.

Creosote / Pigment Emulsified Creosote

I was always under the impression creosote treatment utilised the same material that is the by-product of burning wood – the stuff that clogs up your chimney known by the same name. I always wondered why it smelled different. Because it is.

Creosote has been in use for over 170 years. The original creosote for preserving timber was made from coal tar. Wood creosote is used in other applications, or if used in treated timber, it is mixed with coal tar creosote. Other varieties of creosote made from petroleum and oil are called oil-tar creosote. 

Fossil fuel based creosote products are known to be carcinogenic and can contaminate water supplies.

I chose creosote posts as fencing strainers on my property thinking they were treated with the wood form and probably more environmentally friendly than CCA posts. I’m not so sure now.


Alkaline Copper Quartenary. This is what I was going to purchase for my raised garden bed, but it has higher copper leaching than CCA and therefore higher aquatic toxicity in that respect.


Copper dimethyl-dithiocarbamate. Contains copper and sulfur compounds. Seems to be a relatively uncommon treatment and I don’t know much about it. It appears to have less copper leaching than CCA, but I found quite a few references to CDDC being toxic to animals in laboratory testing.


Ammoniacal Copper Citrate. Contains copper and citric acid. As with ACQ, it leaches more copper than CCA.


Liquid Organic Solvent Preservative. It may include tributyltin (TBT), a persistent organic pollutant and permethrin; a common synthetic chemical widely used as an insecticide. As to its toxicity, let’s put it this way – LOSP treated timber is not recommended for children’s toys or anything touching food, such as cutting boards.

Treated timber for marine applications use other chemical compounds, which appear to be even more nasty.

Wood is natural. So are copper, arsenic and chromium. Natural doesn’t harmless. All the types of treated wood mentioned above come with a variety of safety warnings to be observed when working with it – such as wearing masks, long clothing, washing thoroughly after working with it, etc. etc. etc. There is no form of treated timber I know of that can be safely burned either. It doesn’t exactly inspire confidence as to its general health or environmental street cred.

It’s not just the wood

The chemical treatments applied to timber don’t appear magically – they must be applied somewhere. Sites that treat timber have been in the headlines a number of times in regard to contamination issues. Before the treatment, there’s also the source of the chemicals and elements themselves. For example, copper mines are notorious for making the land around them barren or saturating vegetation in the surrounding with copper and other toxins, making it harmful to grazing animals.
While the above all seems rather frightening, we need to bear in mind timber is treated to repel living things – by its very nature it is meant to be toxic. It certainly has its place, but the term environmentally friendly treated timber is an oxymoron.
Recycled Composite Plastic Timber

Recycled Plastic Uses – Composite Timber

March 14th, 2012.

I had a garden-bed type project on my to-do list and needed to find something to use as borders.
I would have liked to use plantation pine, but aside from rot, the white ants (termites) are very active and hungry critters out here and would have started chomping away at it before I’d fixed the final screw. 
Hardwood was an option, but the hardware store I visited couldn’t tell me much about the origin of their stock – whether it was plantation timber or the result of clearing – and the termites would have had their way with it in the end also.
Rocks and concrete weren’t an option either.

Then I started looking at various treated pine products. Every treatment appeared to have the potential to leach some form of chemical into the soil (stay tuned – article on this topic in the works).

So I settled on plastic. Yes, plastic. 
This may sound at odds with what green living is all about, so I’ll quickly clarify before you scoot away in disgust. Recycled plastic composite timber.
Composite plastic timber is the result of upcycling – or downcycling depending on how you look at it. These products give new life to plastic destined for landfill and wood waste, such as sawdust.

The product I chose is made by Plastic Recyclers Australia. They sort waste plastic, which is processed into granulated form and then melted and mixed with wood fiber. This is then forced under pressure into moulds, which are cooled in large cold water tanks until the plastic is set.

UV stabilized, these boards are resistant to water damage, termites and do not leach chemicals, so it’s safe to grow veggies in a raised garden bed using this as a border/retainer. Unlike working with wood, there’s no danger of splitting boards – I only have to look at a pine board and I swear it starts to split. This product can be easily sawn, drilled, nailed and screwed.
The first thing I noticed (as did the courier) is the weight. The boards are very solid, tipping the scales at 4.5kg (~10lbs) per meter (~3.3 feet) length of 20mm x 200mm (~3/4″ x ~7 3/4″) board. 


Raised garden bed kit made from
recycled plastic composite timber
(small grubby dog-like creature optional extra)

Composite plastic lumber certainly isn’t as cheap as pine or even many types of hardwood, but the company offers a 15 year guarantee and I can see why – this raised garden bed may outlast me.
You can buy these particular boards in various sizes or in garden bed kits in any color you want, as long as it’s black :). Being black, I was a bit concerned about the boards getting very hot, so I left one out in the sun for a few hours on a hot day. While the side facing the sun certainly heated up, the other side stay relatively cool by comparison. There was also no apparent warping – according to the company they will retain their shape over their long life. The boards can be painted using a special primer, but then you may face leaching issues from the paint or primer (something I didn’t look into as I’m not painting them).

I have seen other recycled plastic boards around featuring wood-grain type patterns and various colors, but most of those were hollow and I wasn’t confident they would stand up to the harsh conditions this garden bed will contend with.

While Plastic Recyclers Australia’s products aren’t available outside Australia, New Zealand and some parts of South East Asia as far as I know, a search on Google for composite plastic timber (or lumber) may turn up a similar product in your country.


Ryobi One Plus – A Greener Cordless Power Tool System

February 18th, 2012.

Before I launch into this, I need to say I am no handyman or any sort of expert on power tools. I’m like lightning with a hammer as I don’t strike twice in the same place and while I fervently believe in the “measure twice, cut once” wisdom, I can measure a million times and still stuff up the cut.

I’ve been finding an increasing need to use power tools these last few years; and cordless ones where possible given I’m usually out in the boonies when their use is required. 

I made a mistake with a cordless drill purchase a few years ago by going cheap – and that’s exactly what I got. It was barely up to the job and the battery started failing very quickly. In the end, I just avoided projects that required a lot of drilling.

I wound up with another useless lump of plastic, metal, circuit board and toxins mocking my cheapskate ways and pointing out my hypocrisy at times on environmental issues. I’m thinking of mounting it on the wall by my desk to act as a permanent reminder about some purchase decisions.
Knowing that another drill purchase was unavoidable, I decided to actually consult someone who knows a bit about them this time around and not to focus so much on price (gulp).
The helpful fellow at the hardware store recommended the Ryobi One+ range, which has been around for a while. While he rattled off specifications that didn’t mean a great deal to me, the immediate benefit I could see was a single battery system that can be used with dozens of tools, instead of having a different battery and charger for each tool.


From an environmental viewpoint, this saves substantially on resources and subsequent pollution that go into making chargers and batteries. I think it makes a quite a difference, particularly if you have a dozen different power tools all using different systems.
The range Ryobi offers with One+ is impressive. Aside from the drill, there’s a circular saw, angle grinder, impact driver, finishing sander, orbital sander, jigsaw, reciprocating saw, rotary hammer, planer, torches, spotlights and other various drills – all able to use the same battery and charger. In the USA, there seems to be an even bigger range with 50 One Plus tools all up including a string trimmer, hedge trimmer, chainsaw, miter saw – well, I’ll leave it at that; you get the idea.
I wound up purchasing the drill kit, which was reasonably priced and came with a charger and 2 batteries. 

I really didn’t know what to expect from it, but I was pleasantly surprised when I had to drill dozens of holes into sheet metal of varying thicknesses and diameters in a single session – using old low quality drill bits. The drill didn’t struggle at all and the battery still had charge left afterwards. 

Maybe that doesn’t sound particularly stunning to experienced handyfolks familiar with these sorts of tools; but my other drill wouldn’t have drilled 6 similar holes before starting to fade, even when new.

The system doesn’t feel cheap either – it all seems solidly constructed and unlike my last drill’s charger, this one has indicators for charging state and ceases charging when the battery is full.
Recharge time for a battery is under an hour, which is great if you have a solid amount of work to do, particularly with the second battery in the kit. Recharging is a little sweeter and greener for me as the electricity is generated by a solar panel.
It’s an 18 volt system and the batteries are lithium-ion – so they should have a long life and at the end of their life, they can be recycled. Batteries in various capacities are available.
I’m not particularly pushing Ryobi One+ (and I certainly haven’t been paid or otherwise encouraged to write this brief review) – it’s just that it’s the only system of its kind I am somewhat familiar with. Perhaps there are other similar systems around. 

If you’re looking to replace power tools though, give this type of system some consideration. 
Another point to bear in mind with other single-battery-multiple-tool systems should they be available is to check if the company that makes them has a history with the range – and a future. Otherwise in a few years down the track when you need to replace batteries or want to buy a tool that is available now and isn’t then; you’re pretty much back to square one.

An Introduction To Wood Certifications

November 18th, 2011.

 Deforestation has a huge environmental impact and it can be difficult to tell if the wood in items we purchase are contributing to this unfolding disaster. 

If you’re concerned about the provenance (origin) of wood you buy – whether the wood is in furniture, lumber or even the wood used to make paper goods; looking for certifications might provide you with some reassurance.
A product containing certified wood is one where the wood used has been verified as harvested in a sustainable way – including the impact of the harvesting on the surrounding environment in terms of protecting the biodiversity of an area, erosion control and preserving water resources. 

The certification usually also has some social justice aspects in terms of the way workers in associated forestry operations are treated and the impact on local/indigenous communities.
Chain of Custody

Something you’ll often see mentioned in relation to certified wood is Chain of Custody (CoC). This relates to tracking certified raw materials from a forest right through to the final product to ensure that the wood contained in the end product still meets certification criteria. Without this form of tracking, a product may just have a small component that comes from a certified forest and consumers could be misled into believing the product was 100% certified wood.

Probably the best known certification systems are from the Forest Stewardship Council (FSC) and the Program for the Endorsement of Forest Certification (PEFC), the latter incorporating a number of programs around the world. 

Forest Stewardship Council (FSC)

The FSC describes their certification as being:

“..a voluntary, market-based tool that supports responsible forest management worldwide. FSC certified forest products are verified from the forest of origin through the supply chain. The FSC label ensures that the forest products used are from responsibly harvested and verified sources.”

10 principles and 56 associated criteria form the basis for all Forest Stewardship Council forest management standards. They include:

– Conversion of forests or any other natural habitat is prohibited
– International workers rights must be respected
– A ban on the use of hazardous chemicals
– The rights of indigenous peoples must be respected
– Bribery and other forms of corruption prohibited
– Appropriate management of areas requiring special protection

Companies participating in the program are able to display an FSC logo:


On the actual product, below the logo will be a serial code assigned to the supplier/company. The code can be verified via the FSC online database.

One of several different certifications should also appear on goods displaying the FSC certifications – 100%, Recycled or Mixed.

Products displaying the “100%” must have all the wood components originating from FSC certified forests. 

The “Recycled” certification means the product has a minimum of 85% of the wood fiber content coming from post-consumer sources. The remaining material must be verified as pre-consumer waste.

“Mixed” means the product has a mix of fiber from FSC Certified forests, plus recycled content and/or from “controlled” sources – i.e. harvesting operations not certified, but verified not to be engaging in the most destructive of forestry practices.
So, given all that, you would expect any product bearing a valid FSC certification to be a tree-hugger’s dream. However, like any program, the system reportedly has its share of problems – but how much truth is in what I’ve read I really can’t say.
As mentioned, the Forest Stewardship Council certification isn’t the only game in town.
Program for the Endorsement of Forest Certification (PEFC)
PEFC claims to be the world’s largest forest certification system. It’s an umbrella organization endorsing 30 national forest certification programs. Its members include:

– Australian Forestry Standard 
– PEFC Canada
– PEFC United States

Over 244 million hectares of forestry operations have been certified under the PEFC umbrella. National systems wishing to be recognized by the PEFC must undergo “rigorous independent assessment to ensure their compliance with PEFC’s Sustainability Benchmark,” a set of over 300 criteria.

The PEFC certification logo looks like this:


It should also be accompanied by a serial number assigned to the company/product displaying it, which can be verified here. The mark may also be accompanied by that of the organization under the PEFC umbrella, e.g. the Australian Forestry Standard logo.
As with the FSC, the PEFC also has its share of issues it would seem; but in either case it needs to be weighed up if the downfalls overshadow the overall good achieved through the programs – something I haven’t researched enough to offer an informed opinion. The most common criticism I’ve seen is standards not being applied in practice.
No doubt other certifications exist, but whether it’s FSC, PEFC or some other mark; read up on the program and check other sources to ensure you’re comfortable with how the certification operates before making a purchase decision based on a product proclaiming it is made from certified wood. After all, you’ll likely be paying a premium for that product.
Also be sure to verify that the product or vendor is legitimately displaying such a certification.

Selecting a rainwater tank – materials

April 10th, 2011.

First published December 2007, updated April 2011

Drought is a part of normal life in many parts of the world and given the threats posed by climate change, place with traditionally low rainfall may become even dryer and long established rain patterns give way to major rain events – a feast or famine scenario. A way to better utilize the feast to help through the lean times, or in other disasters where mains supply may be cut or contaminated is to install a rainwater tank 

Here in Australia, the corrugated metal rainwater tank is somewhat of a national icon. In South Australia, around 30% of homes have rainwater catchment systems. Water tanks haven’t been an overly attractive home addition until recently; although seeing the old style tank does make me feel very nostalgic! These days, tanks come in all sorts of shapes, colors, materials and sizes to suit any home and space.

Even if having a full size water tank isn’t an option for you, rain barrels are a very cheap and easy to install option. These look like a pickle barrel, are mostly made of plastic and hold up to 80 gallons – you can pick them up for around a hundred dollars. Ever gallon of water saved counts!

In regard to larger tanks where construction is a more important aspect, in this article we’ll take a brief look at the various materials commonly used, their advantages and disadvantages.

Poly (plastic) rainwater tanks

Poly tanks are made from polyethylene; a UV stabilized, food grade plastic. The tanks are light and you only need a sand base to place them on. They come in a wide variety of colors, usually molded into the plastic, and have a long serviceable life. Many poly tanks carrying a 25 year warranty, although many claim 15 years is a more realistic lifespan. They are also usually the second cheapest of the options covered in this article.

One of the major disadvantages of polyethylene is the material is made from petrochemicals. Even after their serviceable life has ended, there’s still a great big hunk of plastic that will take generations to break down and will release toxins as it does so.

However, polyethylene tanks can still be easily recycled after 15 years, so it’s just a matter of breaking the tank up and then carting it away to a recycler.

Some poly tanks are made with a vertical seam – this is a weak point that may cause splitting and subsequent water loss – so a seamless tank is probably a better choice. Polyethylene water tanks and fire don’t really mix either as they’ll just melt should the flames get too close. This can be a real problem if you’re in a rural area and you need that water to fight a fire.

The other issue is the long term effects of drinking water stored for such a long time in this material. Polyethylene tanks are relatively new on the market, so there’s no serviceable life studies been performed in relation to these issues as far as I know.

I had a polyethylene rainwater tank at my original place in the outback where temperatures would get up to around 46C (115F) degrees Celsius in the shade and below freezing during winter. The tank performed well over the couple of years I had it before selling the property, but there was a bit of an odd taste to the water on hot days (it was placed in full sun). A subsequent poly tank I acquired for my current property has also stood up well to similar extremes – and without the odd taste being added to the water.

Just on that point – before purchasing a poly tank, check the warranty for temperature stipulations as some manufacturers will void the warranty if conditions where the tank is installed can get extremely hot.

Steel tanks

Three materials are most popular – Galvanized steel, Zincalume®  and Colorbond®  (the latter two may be called by other names in different countries).

Galvanized tanks have been around for over 150 years and are usually the cheapest type of tank. Hot-dip galvanizing is a process used to coat steel or iron with zinc. The Zinc helps slow down corrosion, but depending on environmental factors, a galvanized tank may last well under 5 years, particularly if the roof of the structure capturing the rainwater is made from Zincalume. This is due to electrolysis.

Zincalume®  has been around for about 30 years and was originally used for roofing. It’s a a mix of 55% aluminium, 43.5% zinc and 1.5% silicon bonded to steel. There’s a lot of conflicting information around about lifespan, but the general consensus seems to be about 10-15 years.

Colorbond is Zincalume with a conversion layer applied to the surface of the steel to improve adhesion; then a polyester primer baked on, followed by a top coat of paint that is also baked on. It’s not unusual to find a 20 year warranty on these tanks, but a deep scratch to the paint can be enough to accelerate the corrosion process.

Some metal tanks now also have polyethylene linings to further help slow down corrosion – escaping plastic altogether can be a difficult thing to do these days.

If you do buy a steel based tank, look into installing extra sacrificial anodes to further delay corrosion.

Concrete water tanks

Concrete rainwater tanks can be installed either above or under ground. The latter is a good option if you’re short on space as they can be constructed in such a way to allow for load bearing, for example, under a driveway.

Given the material, they are very heavy and often poured on-site or delivered in sections that are then basically cemented together. Again, a polyethylene liner may be used. Without a liner, the tank will leach lime and over time you’ll have a slightly alkaline water. With concrete being porous, without a liner water will penetrate into the concrete over time which may cause corrosion problems in relation to steel framework.

Concrete is also an energy intensive product that requires a great deal of heat and water in its production. Additionally, the components need to be mined – but the same goes for any material.


This is another long-lasting option that can be installed above or below ground. Fiberglass tanks resist corrosion and are not generally affected by chemicals.

As fiberglass tanks tend to allow more light in than other types of tank materials, this can encourage the growth of algae, so they should be painted or gel coat applied. Fiberglass can also tend to be brittle, leaving it prone to cracks – something you don’t want, particularly in an in-ground situation.

Choosing a tank material

Choice is wonderful, but as you can see, there’s advantages and disadvantages with each type of tank, particularly when it comes to environmental impact – so it’s really a matter of gauging your needs and budget and then choosing the lesser of the evils. In regard to the financial side of things, bear in mind not just the initial cost, but how many times the tank will need replacing over X years. This also plays a role in the amount of resources used. 

Something worth checking into are rebates on rainwater tanks and/or associated plumbing – many governments now offer cash-back schemes.

Even with the various disadvantages of each material, given the length of serviceable life of most tank options and the tens of thousands of gallons of water you can collect over that time; installing a rainwater tank is still a very green move.

A brief note on rainwater tank regulations

Regardless of the material you settle on, before buying and installing a tank you should check with your local authorities as in some places you will need a special permit and in others they may be totally banned – which is absolutely ridiculous in my opinion. Even in Australia, the driest inhabited continent on Earth, some local governments had bans in place until relatively recently – but the Millennium Drought thankfully sorted out most of those short-sighted councils.

Australia wasn’t the only country with crazy laws regarding rainwater harvesting. Up until 2009, in Colorado in the USA, it was illegal for households to capture rainwater as rights to water were allocated in the state; i.e, that water that fell from the sky was owned/leased by other parties.

I’m pleased that sanity prevailed in that case also; but no doubt there are still some regions where similar silly legislation is still in place. If you’re unfortunate enough to live in such an area, consider organising protest action rather than letting the status quo remain.

Think reuse before recycle

October 6th, 2010.

(First published April 2007, Updated October 2010)

The recycling movement has gathered plenty of steam in recent years which is wonderful as there is far less waste hitting our landfills and far more resources being reclaimed.

However, there is concern building that the recycling wave is allowing us to still be rampant consumers, a throwaway society; and recycling some justification for maintaining this mindset.

Take for example those very handy cans of gourmet tuna. These are great to pack in a lunch box but I can empty the contents with a single mouthful! I can alleviate my guilt somewhat by recycling the can, but in order to get that mouthful of tuna, an awful lot of resources have gone into the packaging – and that’s not to mention the added costs in purchasing products using “convenience packaging“.

What’s more economical and energy efficient is buying a larger can of tuna and spooning out the equivalent amount into a reusable container. The only problem there is if the contents of the larger can aren’t eaten – and food waste is another massive environmental problem.

It’s the same sort of situation with a plethora of other products – cans vs. large bottles of drink, traveller packs of anything – all these handy sizes which cost us more can be recycled; but we forget the amount of energy it takes to do so.

While the energy required to recycle the aluminum in a drink can is one twentieth of that to produce the can from raw materials; when you start thinking in terms of billions of cans; it’s still a lot of energy consumed. You can buy the equivalent of 5 cans in a plastic PET recyclable bottle and I suspect (I’m not sure on this) that the recycling process would require less energy (although PET bottles are actually downcycled).

The downcycling aspect is another trap many of us fall into – downcycling is different to recycling in that the packaging being processed is made into something of less value. True recycling is where more of the same product is made; but the term has been extended to cover a variety of different actions.

The case for reuse

In terms of larger items, let’s say an old busted washing machine – we can send it to scrap merchants who may strip it of useful components for recycling which is great; but Fred from down the road is handy with washing machines and he may find that it just needs a fuse or some cheap component. Fred may be able to make use of it or resell the item. Reuse extends the life of a product before it has to hit the recycling stage. You may have saved Fred (or someone else) some cash in having to buy a new washer, so there’s also a definite feel good aspect to re-use aside from the consumption issue.

According to a (rather old) article on the US EPA’s Institute for Local Self-Reliance site, “New recycling-based manufacturers create 25 times the number of jobs as landfilling. Some reuse operations employ 200 jobs for every one job at a disposal facility.”

With the growing number of people understanding that reuse is the first option before recycle, all sorts of groups have started up where you can offer your items for free to others who can make use of them. One such service is The Freecycle Network™ which currently has nearly 7.6 million members globally. 

Another interesting service is ecofreek; which searches over 45+ sources for free and swappable items being given away by people who no longer need them

I’ve read some amazing stories of people who believed *no-one* could make use of their junk, only to find it snapped up when posted to these sorts of sites.

There are also an increasing number of trash removal services that will sort through your waste for you, diverting whatever possible for composting, recycling and reuse. These services cost a little more, but in my opinion are well worth the money.

So, recycling (in all its forms) is bad then?

While some will understandably frown upon the heavy emphasis of recycling for the reasons above; I still think that recycling is an incredibly important thing to encourage. Aside from the reclamation of resources, recycling is a “gateway” green action.
So many people start their green journey by recycling. It’s these easy actions than can encourage bigger changes down the track. For those of us down the green road a little however, the reuse vs. recycle issues are something we should bear in mind.
Even more importantly, we need to reduce the amount we consume – that’s why the 3R’s of green living are in the order they are – Reduce, Reuse, Recycle.