Lime plaster has been used for construction since before the use of cement. In recent years only it has become more popular because it is more environment friendly than cement. Lime plaster forms a very clean, light and durable surface that is resistant to harsh weather conditions and mold.
Lime plaster can burn you badly if you leave it on your skin for an hour or more. Please pay a careful attention to your safety:
- Use rubber gloves, goggles and wipe off your face, arms and legs often.
- You can mix one batch in a wheelbarrow. Mix larger quantities on a tarp placed in a hole.
Ingredients for Lime Plaster
To make lime plaster take 20 litre bucket of Lime Putty, 5 gallon (8 kg) of short fibers, three 20 litre bucket of sand
- Screen the sand with a window-screen if it contains small stones.
- Wash the sand if it contains any salt or dirt.
- Spread the sand and putty in thin layers. Mix it together well with a hoe. Add only a little water. All the sand grains should be covered in liquid putty.
- The plaster should be more thick than runny. A little should barely hold onto a trowel when it is held vertical.
- You can even mix lime plaster ahead of time. Cover it properly and keep it humid under a tarp or in closed buckets.
Tips and tricks to make Lime Plaster:
can be used to give strength to plaster, but should be added at most 2 or 3 days prior to use.
Fibers of various types:
- Manure fresh and dry (best from horses or donkeys).
- Straw or animal hair chopped in 5 cm (2 inch) long pieces.
- Cattail heads look like a brown cigar. They grow in swamps.
If the sand contains a little clay, start preparing the plaster a few days ahead of time.
Add one quart of boiled wheat paste to each 15 gallons of sand. The juice of a cactus with flat leaves can help lime plaster resist weather.
- Chop the leaves of Opuntia species (called prickly pear) and cover them with water for 2 weeks.
- Add the juice to your plaster before the juice begins to ferment.
In some regions, very poor quality of hydrated lime is available. Lime plaster made with it will not begin to harden within a day.
Instead use half lime and half Portland cement to make lime plaster in following proportion- 1 part of lime putty : 1 part powdered Portland cement : 6 parts of sand. This mixed Portland and lime plaster will probably not work in thin layers on natural materials as well as pure lime plaster.