[Strawbale] Lime Plaster, The Magic Numbers

[Speireag Alden]

Sgrìobh Debbie Johnson-Jackson:

>We are ready to plaster the inside of our strawbale house and I have
>looked through many books, blogs and list and watched videos and
>while they gives great information on a lot of the steps involved in 
>plastering,
>there is one big areas that is left out. How do we go about 
>determining how
>much lime and other materials to order? I realize that the exact
>amount depends on how the plaster is applied but is there a ball park
>number for say the square feet at 3/4" of scratch coat one bag of lime
>and it's corresponding sand (say 1 lime to 2 sand) will give?

     Rob has already pointed out how to do the volume calculation. 
Bill has pointed out that you have to add a percentage for the first 
coat.  He has more experience than I, but I think I might go a little 
higher than 15%.

     I can answer the question of how much lime you get in a standard 
bag of powdered, hydrated Type-S lime:  enough to make just under 10 
gallons of putty.  That's why I mix it in five-gallon buckets.

     1:2 sounds a bit rich to me, but your mileage may vary.  I use 
1:3, and could probably get away with 1:3.5, though I haven't tried. 
I have access to high-quality lime (GenLime) and I make a point of 
buying it and making putty of it when it's no older than a month old. 
I call up the local building supply and ask them when they're getting 
a delivery.  Sometimes I've gotten it so fresh that the bags were 
still warm.

     Once mixed, the lime putty keeps as long as it's totally 
submerged, so you can put a cap on it and top it off with water every 
once in awhile.

     I write a primer on mixing a few years ago.  I'll dig it up and post it.

-Speireag.

-- 
Anger, if not restrained, is frequently more hurtful to us than the 
injury that provokes it.
--Lucius Annaeus Seneca, philosopher (BCE 3-65 CE)