Ben (NightHawkInLight) has done it again folks!!! This is truly amazing - he has made it possible to make aircrete without any significant tools and it is easy to control the structural vs thermal attributes of it. This may be the PERFECT building material... with just changing the process up by using a tiny bit of xanthan gum, alcohol and soap!
I have watched the video. It is nice, but after analyzing it, it is very expensive. For fun I have calculated cost per block.
Portland cement $4.56 (HD)
natural detergent $2.72 (Walmart)
xantan gum $2.04 (Walmart)
which totals to $9.32 per block (looks like it's lower than standard 8").
Labor to make the forms and the blocks is not included.
The cost of Faswall ICF block would be $12.3 (with average delivery cost) per equivalent of 8x16x8 block. Both would need rebars and grouting, but the aircrete block would have probably less insulating value than Faswall, because of thinner walls and lacking the insulation insert. I picked Faswall, because it has no plastics or nasty styrofoam.
If buying materials in large quantities, maybe, but only maybe, the price could be reduced to $5.
Using not natural detergent would drop the price too, but why to put so much effort and have dyes, synthetic fragrances and allergenic chemicals in the wall of own house?
For comparison in Europe, the same size Ytong (AAC) block (solid) costs $1.6 and insulating clay block $1.8.
Let's check how it compares for plaster. It could be useful as insulating plaster if applied thickly 25mm/1". For covering 1m2 it would need equivalent of 2.2 blocks so $20.5/m2.
For comparison lime plaster (not insulating) made from high calcium lime and sand would cost $4/m2 or less if sand was bought by a truckload.
One bag of cement, one bottle of detergent and the bag of xanth gum makes a lot more than one block.
The other blocks you mention are not available locally for me.
I don't think I would use it as mortar, but using it as filler in a conventional block or even a stud wall is very appealing.
Using it as insulation behind a hard firebrick hot face also seems promising.
I fear even the closed cell version would soak up too much water to be a good outdoor wall cladding, but it were sealed, maybe it would work.
This idea is fascinating to me on many levels. Yet more questions remain, perhaps more than answers, indeed.
Portland 94 lb bag costs about 20 clams for me, hurting my wallet as much as the shoulder I use to carry the damn thing. It is nice to have options by buying this, adjusting ratios to sand in myriad circumstances. So the number posted here must estimate the amount used for a block, I am guessing. So is that about 9 blocks crafted per bag of Portland? The total price per aircrete block still seems cost prohibitive
But the basic idea, adding insulation via air pockets in a block, is an important advance. How best can this be achieved?
This is another example of my basic incredulity about our capitalist system, which proclaims to have open competition....but then how do we square the idea that a project I buy block for in the EU has amazing choice available for block? And the USA has very little affordable choice ,ready made ,for the exact same project? Those insulating clay based block in Europe are amazing to use, effective and affordable, full stop. And if one percent of the red clay in GA was dug up, I bet we could have the same product for sale here.
Could anyone share their experience on this topic? I hear William , and have a hard time comprehending "how we got here"
Going from his recipe of 4 liters of dry Portland powder per block, I get 7 per 94 lb bag.
The bags are 17 dollars where I live, but going with $20 per bag that's a base cost of $2.86.
If you used an entire bottle of dishwashing liquid and an entire bag of of xanth gum for each block, you would still only spend an additional $4.76
Im just gonna round up to $4 per block.
That's way more than I pay for conventional block, but conventional block has no insulation value to speak of.
It still makes little sense to use this material to build a block wall.
Where are you going to need a structural element that isn't lab tested?
Even if you are building without permits, $4 dollars per block plus the labor involved is a lot.
Better to use it as a pest proof pour in insulation in an already self supporting structure.
It would add lots of strength, but you wouldn't be relying on it for that.
If I were making custom blocks anyway, then I would find it worthwhile.
A trapezoidal dome built of custom aircrete blocks, that makes sense to me.
Post by:autobot
I've read about this kind of thing at the checkout counter. That's where I met this tiny ad:
A rocket mass heater heats your home with one tenth the wood of a conventional wood stove
![[Logo]](/templates/default/mobile/images/mobile-permies-2015.png)
