Last night we cracked open a bottle of champagne to celebrate what has been an extremely long process! Our large exterior eastern facing door has been installed! We should have been locked up last year so it is with much relief and great celebration to reach this stage. We have had a productive week, with many trades dropping in on the site to do work. Grant has been retrofitting the old part of the house by hempcreting the ceiling to provide us with superior insulation. I have been working on waxing the bamboo cabinetry using a product called Treatex traditional hardwax oil. Pictures to follow.
The most important picture is the one beneath theses words. How glorious it is to have the door in, and lockable. It has large proportions and feels incredibly solid. There is still a couple of things to complete the door. Down at the base we need to place an angled door trim so we don't trip on the doorway. This will be placed once the concrete floor has been polished.
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| This is it, the door that has delayed the project by months! |
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| Toffee already enjoying the sun streaming through our door! |
I too am hoping to have a polished concrete floor. Interested to hear about the hempcrete ceiling insulation. What depth and R value will you be installing and does the ceiling need to be stronger to take the weight?
ReplyDeleteWe installed the hemp ceiling insulation to 150mm. It is a lighter mix than the walls using half the lime and no sand. The link below has some data about the R-values which should be around 3.0 for our ceiling. However, as this page explains, you could expect better performance than from equivalent R3.0 insulation batts. We also installed Ametalin Fat Max SilverBatts directly under the roof. This is to control the summer sun load as it is a foil batt that can reflect radiant heat and creates a thermal siphon to move the heat out of the attic. I estimate that the effective summer R value would be over R5.0.
Deletehttp://hempmasonry.com.au/thermal-performance/
http://hempmasonry.com.au/insulation/
We chose to use 10mm magnesium oxide lining boards from Modak (now called Firecheck) and installed the hemp on top of the boards. You can’t use plasterboard as it doesn’t breathe and also won’t survive when the wet hemp is installed. You could also do a rendered ceiling similar to lath and plaster in old houses.
We also ensured that the roof structure could support the additional weight of the heavier ceiling boards and hempcrete. Up front, I decided to space the roof trusses at 600mm even though 900mm would be strong enough to hold the weight. We wanted to be sure there was no sagging of the lining between the trusses. The roof truss fabricator was provided with the mass/unit area for both wet and dry which was obtained from the supplier to include in the calculations. The trusses were all able to be made from 90x35mm pine so you could say that it is really just a conventional roof.