Cement Mixers

I'm getting close to starting on my straw bale house. The straw bales are rendered in 3 coats of an earthen render. This is pumped on with a render pump. The earthen renders is made from powdered clay and sand.

I will probably need to have two cement mixers going to feed the render pump. It will take a day or 2 to do each layer of render.

I'm building the house in 2 stages plus I'm going to build a horse shelter and a green house out of straw bales so I'll need 2 mixers for around 20 days.

The questions are:

Petrol or Electric? I'll have power to the site.

Rent or Buy?

Should I buy good ones second hand or buy GMC jobbies?

Should I be asking so many question?

G'day Grunt,
at this stage you should be asking as many questions as you feel are necessary.
To explain:
One year I bought the wommo a book on Straw Bail building. Probably 10 years ago.
Next thing.......railway sleeper posts...lots of holes......big bolts....lots of concrete.......frame up.......cut and bale the paddock........put up the roof.......cure the straw under plastic over winter. Then........here's the big secret!!!!
According to the book I bought, traditionally, only women render the straw bail structure.
True!
My wommo extended this theory to stacking the walls and rendering, which she did by hand.......cement/sand render........3 or 4 coats. She mixed the render in a barrow with a hoe and a rake, used good riggers gloves and rendered each 6 metre long wall by hand......inside and out.
I was gonna send you the book, but maybe I should send the missus!

To seriously answer your question, I would buy GMC jobbies....the reason is......it will take longer than you think....its gonna rain on your parade.....so hire costs will blow out.......and the guarantee safeguards you in most cases....and you will always need a mixer if you're building your own house. And I go electric...costs less to run in the long run.
I'll try and post a photo of what's been done here.

Watson is a wise fellow! :wink:

1) It's women's work, so you might get away with a larry and a barrow.

2) You'll need them for longer than you think, too long to hire them, but not long enough to wear out a good one.

Go the GMC, treat them kindly (no banging the bowl with a spade and stuff like that). Keep them really clean, and flog them when it's done, or flog one of them at least with 18 months warranty.

It's exciting times Grunt. All the best. I look forward to hearing progress reports!

Cheers,

P
:D

Thanks,

I'm planning to start a blog on the project. Haven't decided whether I'll just do a thread here or something a bit more fancy.

I did a Straw Bale building course a few weeks ago. Worth every penny. It was run by a bloke who has been a builder for 30 years. He knows how to build a house.

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1) It's women's work,

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I'll be right at home then.

:D

Grunt,
what's a render pump? Will you be operating it or are you getting a contractor in ? If the latter ask him what's required to keep up/how many barrows per hour. I wouldn't have thought that you'd need two mixers going to feed render to one applicator, even if they were using a pump of some kind, but then I've never seen a straw bale house rendered. Maybe try just one mixer to start with and buy a second if required. One person feeding two mixers won't be twice as fast as one person feeding one mixer, I doubt it would even be 50% faster. If you have to barrow the mix anywhere (ie to the pump or the applicator) then you'd fill the barrow, feed the mixer and then push the barrow whilst the next load is mixing.

Mick

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Originally Posted by Grunt

I
I'm going to build a horse shelter e out of straw bales

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A horse shelter out of straw bales:? Will it be stable? :lb: :D

I hope you do go ahead with the blog, I've never seen a straw house being built, it will be a very interesting thread.

Good luck.

I'm getting a contractor to do it. A render pump is a bit like a concrete pump except it spits the render out at 120psi. Don't want to stand in front of it. I was advised that two mixers was the go.

On render days, I'll need a few bods around. Probably 3 to man the mixers, 1 to pump, 1 to spray water on the straw before the render goes on and 1 or 2 to trowel and smooth.

I'm doing a horse shelter starting in next week or so as a bit of practice. I'll manually do the render on this tho.

Chris

So these four or five extra bods, do you need to pay them? If so it may be cheaper if you can find a bobcat with a quick-tatch mixer to scoop up the render ingredients, mix them and feed the pump. Then you could have one person spraying the straw bales and maybe doing a bit of trowelling and another just trowelling. Also, the render pump bloke, is he used to two large mixers (3.5 cubic foot rather than the 2.2 of the smaller ones) fed by brickies labourers? That's probably equivalent to 4 or more small mixers fed by amateurs.

Mick

G'day Mick,
Really good points there...as to blokes/rate/work/capacity....
Bobcat is a good thought, but I know it'll go slower than planned.....so maybe Grunt should hire my missus..........geez I hope she never reads this stuff!!
So Grunt's using an earth mix render......what additives to the mix???
Just trying to work out how quick it'll mix..........earth renders are notoriously "let soak overnight" type of things.
Interesting stuff.


Oops just looked at the time....going to bed.....not saying "nitey night"....just won't answer anything until tomorrowday.
and I know I've been spelling bale incorrectly all night. Nite

I've got a GMC mixer and it is good enough for little jobs
EXCEPT its horribly underpowered,
so stick a bigger motor on and you'd have a real good mixer

I bought a mixer from Bunnies (I think, may have been Mitre 10), thin bowl but as I am not a builder it's been OK, we mixed up a 40kg bag of concrete with a big bucket of dirt and another of cement last weekend and it didn't pull up, fair amount of water to make it a real sloppy mix that would pour and self level.
I don't know what size the motor is but looks like about 1hp induction.
Only problem I have is instability when the tyres deflate a bit.
The mixer is not a GMC but probably comes out of the same factory.
I have had this for almost three years and for our occassional weekend warrior efforts it has worked out OK.

If you decide to go with the two cement mixers, I would look into the second hand market. I reckon heaps of people buy the best on the market, use it a few times, then flog it for the next toy.

Worth a look anyway!

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So these four or five extra bods, do you need to pay them?

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No, I intend to burn a few friendships. :)

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So Grunt's using an earth mix render......what additives to the mix???

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The mix is about 5 to 1 sand to clay depending on how much clay is in your sand. The render goes on in 3 coats. The first is only clay and sand. The second would have about 5% lime maybe up to 10% if the weather is a bit damp and the last coat is 10% lime.

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Just trying to work out how quick it'll mix..........earth renders are notoriously "let soak overnight" type of things.
Interesting stuff.

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On the course I did we mixed it and whacked it on straight away. We looked at a number of houses that were built using this mixture and one was 6 years old and looked brand new.

I used to have an electric mixer many years ago and it was great for my needs. Always started when you turned on the switch unlike petrol driven ones when they are only used intermittantly.

Unfortunately I sold it about 10 years ago otherwise you could have borrowed it. Maybe others have some available for loan?


Peter.