ahhhh mixing paper and lime is not a good thing to make thick blocks, I was replying about plastering OVER papercrete as the subject was about protecting the finished wall. There is no reason to add lime to make papercrete itself.
to be very clear Lime needs AIR to cure, it will stay soft forever if kept covered under water, or sealed.
Lime when mixed with sand and water and fiber must be applied thinly as a plaster coating, when used as a mortar between bricks it can't be too thick either. in old houses with the brick set deep into the wall the lime mortar is still soft after 60 years because AIR never reached it to harden fully. Lime will stay soft and never set up if not exposed to air, so you can't put a 3" coat on top a wall, this is why thin layers are done, with a month in between to let the lime cure in the presence of air.
It continues to get harder over decades but never goes over a couple hundred psi, where cement reaches over 2500 psi in 90 days.
In Italy hundreds of years ago families stored barrels of lime tightly covered, and when house repairs were needed, passed down father to son the lime was the same age, and same content/mix, same color, to match the walls.
In the US to repair the White House walls experts were needed to go find the same sand, and process the lime similarly so the lime render would look the same as the historical wall. Modern Alt. builders are now keeping a few buckets of mix for the same reason.
the best way to use lime with paper is to make it be a plaster.
I have done my bathroom walls with shredded office paper* soaked in lime and water, and it comes out an 'old world' look, or it can look like cottage cheese, or like Mexican stucco. ( reminds me, in the US we say "stucco" we mean a "plaster," it is understood that stucco=cement coating while the Brits/Europeans say "render")
And cement processed IS mostly lime, but has clay (and other stuff) added so it has the reaction to set fast.
in the 1850s there were contests when cement was a new invention... brick layers would take pure lime mortar, and add 10% "cement" to hurry the set, then more, then more, as the need for building speed in a growing nation was important. ( Think of the thousands of brick buildings in NYC and the east coast as the population grew) Cement helped set the bricks quickly, but it has a negative too. Finally we come to only 10% lime mixed into a cement to keep it "plastic" and workable.
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* the Chinese paper lime recipe. It is applied by hand (gloved) and trowel for the texture you want'
Chinese recipe for Paper Lime plaster [interior use]
By WEIGHT-1 part (lb.) chopped/shredded paper-office paper
to 10 parts (lb.) soft lime putty (type N or S hydrated lime that was soaked in water 48 hours)
Mix well in large bin with tight lid. Seal lid. Let mellow 2-4 weeks.
To use: stir in 1/2-1 parts sharp sand to make more trowelable.
Fine sand gives smoother look, coarse a more stucco look. Mix with paint stem/paddle blade to make creamy..
Spread on wall by hand (always wear gloves) or trowel. Sculpt and let dry. Feather edges thin at stop points. Can be
limewashed; embed tiles while soft. Adding extra sand gives a stronger, more old world
plaster/mortar look .
Successfully applied to new and old drywall, and on particle board on
my work studio & on new greenboard on bathroom walls.
National Lime Assoc www.lime.org/
Pargeting-decorative lime www.kettlenet.co.uk/
US Parks Building articles: www.cr.nps.gov/hps/tps/briefs/presbhom.htm
Lime plaster on Straw Bales: http://solarhaven.org/Construction4Lime.htm
Tadelakt lime plaster- www.naturalpaint.com.au/
Building Conservation-Lime articles: www.buildingconservation.com/
Charmaine Taylor/Publishing & Elk River Press
PO Box 375 Cutten CA 95534
www.papercrete.com
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