I made mud pies today.
Well, I called it "cement render". I'm (slowly) converting a shipping container into a #diy transportable "Tiny Home". I'm a total n00b (almost, anyway) so thought I'd share what I'm learning with you.
Containers are made of Corten steel, which resists rusting and flaking, but only up to a point. I've seen friends' containers rust through in only half a dozen years in the rain, so I decided mine should have an outer jacket of #ferrocement, and a pitched roof over that.
Ferrocement is a flexible mesh of chicken-wire, rendered over with cement. After grinding and brushing off rust spots, I secured my chicken wire mesh to galvanised barbed wire with ring staples, and then the barbed wire to the container skin with welds. Well, I tried. Very hard to get a good welding "earth" onto the container, and thin Corten doesn't seem to conduct very well anyway. So I also used lengths of steel strapping over the wire and riveted through the sides of the container (never the top, I don't want to risk leaks!). 2.4mm mild steel rivets, don't use aluminium rivets the alkaline concrete will turn them to too.
My container is now swathed in chicken wire like a Byzantine Kataphract in chainmail.
Today I started cement-rendering over the top. Its been nearly 20 years since I worked on a building site (student job), but I asked around, and read forums. The render recipe I settled on is 6:1:1 - six parts sand, one part Portland cement, one part lime. And a splash of plasticiser, and a handful of stabilised chopped glass fibre in every bucket.
Yes, I made the render in a bucket. Every tradie mate I spoke to sternly insisted I get a cement mixer for making render. I could, but they take up so much space if I buy one, and cost an absurd amount to hire one, and then I'm on a timer for my weekend project. No. I've made cement mortar in a bucket before, with a mixer bit on my good corded drill, and it worked out fine. Render can't be that different, right?
Today I learned it is, and it isn't. You can get away with a little excess water in a mortar (makes mixing much easier), but render _needs_ to be as stiff as possible. Once I figured that out it mixed a bit slower but otherwise okay.
I work out nearly every day, but carrying buckets of my "mud pies" up a ladder still took it out of me. It's a different kind of fitness, hat off to the boys who do this for a living!
Just did one layer on the top today, will see how it goes. I had the mesh and barbed wire attached with quite a bit of slack, in places it wants to poke up out of the render, but a top coat should fix that.
Next weekend, maybe!
