House bloggy thingy stuff no. 1
I've realised that there are many things that happyinmotion and I are doing with our house build, that we've never fully explained, and that might be interesting and useful for people to know more about. So I’m going to write a series of posts about different aspects of the build, focusing on the things we’ve done to make our house more eco-friendly and healthy. I’m especially going to cover aspects that could be applicable lots of projects - things that you might like to look into if you’re building, renovating or landscaping.
Before I start, I want to say this. There are lots of ways to go about eco-friendly/healthy building, and there are lots of different views on the relative importance of different aspects. I’m going to write about the way that we’re doing it - the path that we have used to navigate the competing demands of sustainable/healthy housing, our “interesting” building site, the local climate, and the way happyinmotion and I live our lives. Many times we have had to make compromises. For example, our initial inspiration for building came from some stunning New Zealand earth buildings such as this one. We read about these houses and wanted to build from earth brick. I love earth houses, but when we considered our steep building site, the frequent horizontal rain that we get here, our busy lives, and the fact that we wanted to hang a trapeze in our house, it became apparent that earth brick was impractical. Any gain from earth brick would have been too small to offset the extra difficulties.
Timber treatments: would you like some arsenic with your deck?
The days when the council would let you build with little or no timber treatment are long gone. We’ve tried to minimise the amount of treated timber we have used, where possible using species that don’t require treatment: macrocarpa posts and beams, and lawson’s cypress decking and weatherboards. However, all of our roofing and exterior wall framing has had to be built from treated pine, as was our entire cardeck.
In New Zealand, we usually use CCA-treated timber for these purposes. CCA stands for Chromated Copper Arsenate which is a mix of copper, chromium and arsenic. Yes, that’s arsenic, the poison of kings. Also, chromium(VI), which is toxic, carcinogenic, and considered to be a serious environmental contaminant. CCA is certainly effective at preserving the timber, but working with the timber is hazardous (and people rarely take the safety precautions they ought to take with it); offcuts need to be disposed of into a secure landfill, and in the last few years it’s been found that small amounts of arsenic do in fact leach from the timber into the soil. The use of CCA timber has been restricted in Europe, Canada, Australia, and the US, but not in NZ.
So, instead of CCA, in the situations where we need to, we have used ACQ treated timber. ACQ stands for Alkaline Copper Quaternary and is made up of copper oxide and a quaternary ammonium compound. It’s still toxic; we still have to be careful how we use it and how we dispose of it, but it hasn’t got arsenic or chromium, and testing has suggested that it is less toxic in land based environments than CCA. Also, we like our builders and we feel better about ourselves knowing that we’re not causing them needless exposure to the risk of arsenic or chromium poisoning!
There are some down-sides to ACQ:
(1) The high concentration of copper makes it more corrosive than CCA, so you are more likely to need to use (teh expensive!) stainless steel bolts and such. Then again, most of Wellington is close enough to the sea that stainless is a good idea, and it is often required by building codes.
(2) The high concentration of copper makes it very green. As in the colour, not the political leaning. Apparently some people dislike that - we couldn’t give a stuff.
(3) I believe it is somewhat more expensive than CCA, in New Zealand at this time.
So, if you are planning on building a retaining wall, a deck, or something else that requires treated timber, take a look at options other than CCA. If you want ACQ, you will generally have to get the hardware shop to order it in for you. Big chunks of untreated macrocarpa might also be possible, depending on what you’re building.
There's one other little-known benefit of ACQ. As proved by this photo, it's a very effective volunteer-attractant, so if you use it, you can get your house built almost entirely for free by your friends. Hurray!
Next episode: non-toxic paints and oils.
Also ... let me know if there are aspects you’re particularly interested in hearing about and I’ll see what I can do.
Before I start, I want to say this. There are lots of ways to go about eco-friendly/healthy building, and there are lots of different views on the relative importance of different aspects. I’m going to write about the way that we’re doing it - the path that we have used to navigate the competing demands of sustainable/healthy housing, our “interesting” building site, the local climate, and the way happyinmotion and I live our lives. Many times we have had to make compromises. For example, our initial inspiration for building came from some stunning New Zealand earth buildings such as this one. We read about these houses and wanted to build from earth brick. I love earth houses, but when we considered our steep building site, the frequent horizontal rain that we get here, our busy lives, and the fact that we wanted to hang a trapeze in our house, it became apparent that earth brick was impractical. Any gain from earth brick would have been too small to offset the extra difficulties.
Timber treatments: would you like some arsenic with your deck?
The days when the council would let you build with little or no timber treatment are long gone. We’ve tried to minimise the amount of treated timber we have used, where possible using species that don’t require treatment: macrocarpa posts and beams, and lawson’s cypress decking and weatherboards. However, all of our roofing and exterior wall framing has had to be built from treated pine, as was our entire cardeck.
In New Zealand, we usually use CCA-treated timber for these purposes. CCA stands for Chromated Copper Arsenate which is a mix of copper, chromium and arsenic. Yes, that’s arsenic, the poison of kings. Also, chromium(VI), which is toxic, carcinogenic, and considered to be a serious environmental contaminant. CCA is certainly effective at preserving the timber, but working with the timber is hazardous (and people rarely take the safety precautions they ought to take with it); offcuts need to be disposed of into a secure landfill, and in the last few years it’s been found that small amounts of arsenic do in fact leach from the timber into the soil. The use of CCA timber has been restricted in Europe, Canada, Australia, and the US, but not in NZ.
So, instead of CCA, in the situations where we need to, we have used ACQ treated timber. ACQ stands for Alkaline Copper Quaternary and is made up of copper oxide and a quaternary ammonium compound. It’s still toxic; we still have to be careful how we use it and how we dispose of it, but it hasn’t got arsenic or chromium, and testing has suggested that it is less toxic in land based environments than CCA. Also, we like our builders and we feel better about ourselves knowing that we’re not causing them needless exposure to the risk of arsenic or chromium poisoning!
There are some down-sides to ACQ:
(1) The high concentration of copper makes it more corrosive than CCA, so you are more likely to need to use (teh expensive!) stainless steel bolts and such. Then again, most of Wellington is close enough to the sea that stainless is a good idea, and it is often required by building codes.
(2) The high concentration of copper makes it very green. As in the colour, not the political leaning. Apparently some people dislike that - we couldn’t give a stuff.
(3) I believe it is somewhat more expensive than CCA, in New Zealand at this time.
So, if you are planning on building a retaining wall, a deck, or something else that requires treated timber, take a look at options other than CCA. If you want ACQ, you will generally have to get the hardware shop to order it in for you. Big chunks of untreated macrocarpa might also be possible, depending on what you’re building.
There's one other little-known benefit of ACQ. As proved by this photo, it's a very effective volunteer-attractant, so if you use it, you can get your house built almost entirely for free by your friends. Hurray!
Next episode: non-toxic paints and oils.
Also ... let me know if there are aspects you’re particularly interested in hearing about and I’ll see what I can do.