Landscaping, MCA pine decking, lime chip and worms

Although we still have about 2,000 m2 of landscaping to do the outside is about ready.

More diggers have been on site to fill the water tank and parking bay area, level the driveway, dig trenches for waste and storm water pipes which has all been completed now. They also created some walking paths on the steep hill and levelled some areas out. It looks a bit bare and brown now so hopefully after some planting more green to look at.

The deck and deck area around the parking turning bay has also been finished. It was a last minute decision to add the parking bay deck as the drop was over 1m in height and we didn’t want a fence around the parking bay. Very pleased with that choice as it brings a lot more outdoor space and an area to sit and enjoy the view without any fences in the way. Still have to do some cleaning with all the limestone mud smudged all over it.

For decking material we looked at several options:

Pine: the cheapest options but don’t really like the look with its yellow green finish (staining and coloured oils are an option)
Kwila: I love the look of the darker brown timber but ethically not a good choice. There is FSC kwila available but from what I have researched it is still logged from native forests in Papua New Guinea. Some companies claim it comes from plantations, other sites say kwila cannot be grown in plantations. Enough doubt to look at other options.
Composite decking: there are several different options for sustainable composite decking which mostly use a mixture of recycled plastic and waste timber. Ekologix and Outdure are some of the brand options. Advantage is they require little to no maintenance and keep their look. Personally I think it looks a little too artificial and heard some complaints it gets hot in the summer sun and some stains are difficult to remove. Installation can be quicker compared to timber options.
Abodo Sand. Abodo decking and cladding uses FSC New Zealand radiata pine which is thermally modified by steam heating in a kiln which improves its durability to H3 standard without the use of chemicals. I liked the product but in the end chose another timber decking option which was environmentally friendly, had the brown look I liked of kwila and was very well priced compared to the other options namely MCA treated pine.

Most pine in New Zealand is treated with CCA (Chromatic Copper Arsenate). Concerns over the safety of CCA have focused on its chromium and arsenic contents and when burned it also releases toxins. Another concern is the leaching of chromium and arsenic from CCA-treated timber and their release to the environment. New Zealand seems to be one of the few countries still allowing the sale of CCA treated timber. It has been banned for residential use in US, Canada, EU and Australia (but is still allowed to be used for foundations, poles and retaining walls).

The modern more environmentally friendly alternative to CCA is MCA (Micronised Copper Azole) treated timber. It reduces leaching of copper to 90-99%. It has Greenguard certification and can be ordered in as a special order at the likes of Carters, Bunnings, Mitre10’s. Abodo wood would have been the environmental preferred option but thought the MCA option was a very good second choice if you look at the price difference.

Abodo	$ 86/m2
Composite Ekologix	$ 100/m2
Pine CCA	$ 25/m2
Pine MCA	$ 33/m2

Besides material cost the labour cost to install the decking differs too per option. Some composite options are fairly quick to install with clicking systems and don’t require a coating while screw down options require more time. Also 90 mm width versus 150 mm width takes longer. We chose the narrower 90mm option as it matched better with our internal recycled rimu floor.

For the driveway we chose lime stone chip. Our land consists of broken limestone and is very muddy and sticky so we needed something for the driveway. We liked the lime stone chip stone as it was the material of the land and comes from a quarry not far away. The water can easily drain and the lighter colour matches the landscape and beach area around us.

With the waste water connections in place it was time to get some new pets, our worms for the waste tanks. For water and waste water we are off-grid and we have a Natural flow system where worms will do all the work for us together with soakage fields on the land instead of a septic tank.