[Strawbale] more hydraulic vs. hydrated lime

[Jeff Ruppert]

>
> So I'm wondering if, empirically-speaking, not by theory and science but
> by hands-on site-proven experience, anyone has found the NHL to be worth
> the dramatic cost increase....
>   

Jacob,

We chose to use NHL because it works and sets much like cement plaster.  
We have been working as a subcontracting crew on mainstream projects 
where time is important.  If we had to use hydrated lime, the set time 
would have been too long for us to wait after each coat.  I know this 
answer falls within the consumer-based mindset many of us are attempting 
to depart from, but when you are bidding projects and contractors are 
breathing down your neck, the cost of labor tips the balance in favor of 
a product like NHL.  If you cut NHL with hydrated lime, the average per 
bag cost drops to about $23.  If you are using 100 bags of material, 
this is an extra cost of roughly $1,300, and the knowledge along with it 
that it will set up within a day and be ready for the next coat.  The 
cost of $1,300 is equivalent to a crew of six guys at $27/hr, for one 
day.  If we have to work an extra day, or even two, playing with or 
waiting for the plaster to dry, we are equal.  I would rather be able to 
predict how the material behaves more accurately in these situations.  
If you are hiring skilled plasterers who have never used lime, it works 
so much like cement, they can do it without any extra training.

I know this sounds crazy to some people, but when you have crews of guys 
that are half-skilled, working with a high quality consistent product 
can make a big difference.  I also like the product of NHL.  It is much 
like cement and sets consistently.  It is simply a very nice product 
with which to work.  For final coats, many times we have not cut it with 
hydrated lime, in order to have the best quality outer layer.

There are many contractors and owners who fall under the category of 
being very mainstream, but they want to build a bale home.  On most of 
these projects time is so important and bale walls would not be 
considered if they cost even more and took longer than they do when 
compared to conventional systems.  We have been attempting to make sure 
these homes were built with bales.  Whether we were successful is 
anyone's guess, but the fact is, mainstream construction is a different 
animal than owner-builder projects.

It is like any other choice - depends on the project and circumstances.

Jeff "full of hot air today" Ruppert, P.E.
Principal

Odisea LLC
Engineering and Consulting

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