Mud-dauber Wasp demonstrates superiority

I've had a weekend off, but in my absence a tiny little Mud-dauber Wasp appropriated a small corner of the little red window to create an entire purpose-built adobe home for its family, installed the future family in it and stocked the larder with * horror alert * tiny little live paralysed spiders.  Isn't nature grand?

The workwomanship is simply exquisite.  You can just see in the photo the different mud colours.  The wasp has identified that the lighter colour mud from Hepburn is better for building, then it has used our own terra-cotta coloured earth to make it pretty, or camouflage it, or whatever.  It's altogether slightly Attenborough, yes?

The final straw

Gratuitous picture of Trevor

A few hours ago, I placed the final piece of straw in the final light-earth wall.  The structure of the building is done. 

Actually, it was a great way to finish off - I tried out a whole new technique for a different type of wall that we will probably use next time.  More on that later.

Last weekend, TJ put the roof on the bump-out.  That's him on the roof looking groovy with his new hammer drill (a Metabo, replacing the Makita that burned out twice - the Makita fought the shed and the shed won).

This weekend we mudded the last external wall, which was the triangular gable above the window-seat roof.

North wall core completed

The last bit of light earth on the exterior of the building was the gap between the frame and the roof above the new gable panel, to keep critters out of the roof cavity.  I had to get up on the window-seat roof and lie down to get my head and arms underneath the main roof's overhang.  Intensely uncomfortable. 

Gable - done and critter-proofed

You'll notice we buried the raw edge of the window-seat roof in the gable wall.  This is the sort of easy finishing detail you can do with mud but nothing else. It will never, ever leak.

Then we made an interior wall next to where the wood fire will go.

This final wall was an experiment to see if we could make a really solid thin wall, because I think the foot-thick walls on this building slowed us down a bit. If we do this again (TJ needs a woodwork shed) we'll do thinner walls.

The main challenge was to find a way to make the light earth stick firmly to a single stud, instead of having a double-stud "larsens truss" with a cavity in the middle to hold the wall.  After all these months of using bamboo to solve problems, the solution was obvious - TJ drilled holes in the frame and slotted in lengths of bamboo that spanned between solid wood, so when they are buried in a rigid wall they will be completely immoveable. I think in a stud wall for a new building, the bamboo would be horizontal, like a noggin, between vertical studs.

Single stud frame, cement sheeting and bamboo in place

The frame was backed with cement sheeting, to protect from the wood fire.  

Making and positioning the light earth took most of the day, but we completed 3.5m2  - more than double the area we could have built of foot-thick walls.   Don't get me wrong, I adore the thick walls and the curved lintels.  But thinner walls take less than half the time, which is not to be sneezed at - it might have knocked 6 months or more off this project.

Light earth, piggy-back formwork, wall-top technique

The photo above actually shows the last bit of straw we will use in the building.  We ran out of straw at that point and had to scrounge around for fibre to finish the wall.  But it's a good spot to look at the building method, and what we've learned.

Formwork made from scrounged MDF, but reinforced with pine boards.  The pine is offset so one board slots into the one below. In the gap above the top formwork (not usually as big as this, but meh) use a thin metal object like a float, or in this case a plasterer's hawk, and shove the mix in from the side.

And that's it.  The last wall in place.  When I walked outside I looked at the building and it struck me that I've lifted tonnes of mud and straw into place, bit by bit.  And I've grown some muscles, let me tell you.

New wall.  Now it's just fit-out, floor and render

Weekend alone smearing muck onto the walls

On yer marks

I spent last weekend alone and did the thick "parging coat" (undercoat) of render on two wall panels.

I made the job harder for myself by making a really weak, watery render mix on Saturday, which I tried to thicken by adding more fibre.  It was so hard to make that useless muck stick to the walls, I had to abandon my tools and smear it on with bare hands.

Render this - you just need to make mud defy gravity

I made one bucket of stickier render, which I rationed to use on the window surround.  Even then, it threatened to glop off onto the floor every couple of minutes.  I had to keep pushing it in place until it started drying.

Juuuust holding on

Still, I worked at it alone and got the wall finished.  There was a certain amount of "I am woman, hear me roar" going on.

You can almost see how fibrous and nasty the render is from here

Next day, I mixed some render that was extravagant with clay and sloppy as a cow pat. It practically lifted itself onto the wall.

Ta da!

It was peaceful working out there, alone in the bush.  Fresh air, bird-song and fresh food from the garden.  And there's nothing like staring into the corner of a building for two days to make you appreciate the view.

How's the serenity?

Ceilings ... nothing more than ceilings ....

Window seat becomes cosier

Last weekend we put a ceiling on the window seat bump-out, insulated it and finished the walls up to ceiling height. Suddenly the space has a greater feeling of depth and enclosure.

TJ puts up the ceiling boards, blocking out the sky

TJ got some old pine floor boards from a recycled timber yard, cleaned them up a little and put them in place.  That sentence accounts for two days' work!  

When we framed the bump-out we were very careful about the frame being vertical, but less so about it being square.  So there was a certain amount of adjusting and cutting to make the ceiling fit.  Welcome to amateur-land.

We considered at least half a dozen ceiling insulation options.  The main problem was that it's only a small area so there would be heaps of waste using a commercial insulation product.  Then we considered unofficial stuff like loose wool and blankets, until the idea came.

Light Earth insulation

Tucking Light Earth insulation into the ceiling was one of the quickest mud building jobs we've done.  For once, gravity was on our side!  While we were at it, we filled the top of the wall between the windows and the ceiling, so the area is completely enclosed.

TJ adds battens for the tin roof

We've left the insulation to dry under a temporary roof.  We should be able to complete it next weekend.  The other thing we hope to finish next weekend is the gable above the window seat - the last external wall of the mud shed.

Looking in the west wall window