Corrugated Eaves Lining and Light Earth Building

During a few weeks off building what does an owner builder do but help someone else build. Some friend hosted a workshop to build their strawbale extension. The extension also used some internal cob walls and external light earth walls. Here I want to comment on the light earth walls as I was considering building the Culburra house from light earth before deciding to build with hemp. The light earth was enjoyable to build with, but for my project I am glad we used hemp. Light earth is made of straw coated in a light slurry of clay, it is packed into a form work and later rendered after the form work was removed. The builder on my friends job had made his own straw cannon to mix the clay and straw mix. This was a great invention, but I prefer the more uniform result of mixing hemp in a pan mixer, the light earth mix we were working with was quite variable. I was told this was not a problem, but as a more precise hemp mixer this troubled me. I could see the benefit of the light earth was that the materials were cheaper than the hemp and lime mix, but it was also a much more labour intensive job. The mixing was more labour intensive and the packing and tamping required much more physical effort and was more time consuming than laying hemp. Because when we were building we had a labour force of two, or three or four if we were lucky, it was more cost effective to use a less labour intensive building. The light earth seemed to go up quickly, but the workshop had a workforce if about 25 on site, plenty of hand to attend to those labour intensive jobs. As a first time owner builder I have also felt reassured that the hemp sets by way of a chemical reaction and I did not have to worry about the walls rotting before they dried out or of potential moisture problems. Hence my preference to use hemp for my particular project.

Light earth walls

Meanwhile back on site, Len and Ben the plumbers were busy at work installing the down pipes, hooking up the remainder if the roofs to the water tank ( for some time only one of three roofs was plumbed to the tank) and installing the storm water overflow pit, as we have no access to stormwater disposal. The water tank is connected to the toilets and washing machine and is also for outdoor watering. The water from three separate roofs runs into the tank, so that the pipers did not go overhead two of the downpipes are charged pipes, meaning that they are full of water up to the level of the tank. The need for charged pipes meant that we had no option but to use PVC. However a lick of paint in Windspray to match the eaves and tank will hopefully take away the plastic look.

Tank plumbed in

I chose to line the eaves with corrugated Colorbond, as reason for this was for ease of maintenance as there is no need to paint Colorbond, and for the look, as with the skillion roofs the underside of the eaves are much more visible than usual. I chose the standard corrugated profile over mini orb, as with the large eaves mini orb would look too busy, plus the standard corrugated sheets are less expensive and more rigid making them easier to put up.

I chose to run the corrugations parallel to each of the walls and miter the corners. The corrugated sheets were wider than the 600mm eaves and I bought some electric sheers to cut down the sheets and also cut the 45 degree angles at the corners. I was so worried that I would cut the metal the wrong way, because I had to think of the eaves lining above you rather than lying on the ground, that it cut the first angle the right way but on the wrong end of the sheet. As I was fitting the corro sheet into the slot in the metal fascia there was only one way the metal could go.

After that disaster the installation of the first sheet did not go particularly well either. I started on the low side of the eaves, thinking it would be easier, but due to the sloped roof the corro had to be pushed in towards the wall then up before being curved slightly to fit it into the slot in the fascia. The corro got stuck too low on part of the wall and when pushing it up pulled off a part if the render. Hopefully thus will be covered by the angle strip that will be put on later or I can just patch it a little.

Eaves lining in Colorbond Windspray

The next sheet was easier as we worked out the need, on the lower side of the roof, to push the corro up and hard against the hemp wall before trying to push it into the fascia. Cutting the metal, holding it above your head and screwing it in at the same time made for some sore arms. To cheer up after a day of mixed success I put up two more of the Japanese rain chains that take the water from the awnings. It was amazing to see how beautiful a functional object could be, and the shadows they cast were an unexpected surprise.

Japanese rain chain to take water from awning gutter

The following day work resumed on the eaves lining. Putting the corro up on the sloped sides of the house required a bit of scaffolding and a different technique. Once in the right place with the mitred corners matching up we put one screw in to hold the sheet, then one person held the other end while the second person fitted it into the fascia slot. On the high side of the roof the manoeuvring if the sheet was slightly different again, but with the fascia supporting one side of the sheet it was amazing that such large sheets of corro could be held up by two screws, more roofing screws being put in place once it no longer had to be held up. Putting up the eaves lining is really a three person job that we have managed to do with two. We now just have to keep going and put up the lining on the other two roofs and the awnings.

Looking up at the eaves

Nicely mitered corners

Working our way around the house

The good thing about the eaves lining us that you don't really notice it whereas you did when the timber was visible. The eaves lining is starting to give the house a real finished look.