Tuesday, October 27, 2009
Ms. Jimenez came to talk to us toward the end of the first week of the workshop. She grew up in an adobe house, and she had a lot of interesting things to say about her experiences building with adobe.
Ms. Jimenez was the project manager for Simone Swan's house in 1998, so she knew about its construction in intimate detail. The original plaster was earth, sand, and straw. But on top of that was a lime and cement covering. It was painted blue, over the lime and cement. The original lime and cement plaster began to crack eventually, and the cracks leaked. So that original plaster had to be removed, at great expense. That plaster was replaced by a natural plaster of clay, sand, straw and prickly pear juice.
The prickly pear (nopal) pieces are chopped with a machete and left to macerate in water for four to five days. Then the "tea" is scooped out and added to the dry ingredients, along with some manure tea.
Ms. Jimenez said repeatedly that sand and soil have changed since she was a child. It is not as easy to make good adobe as it used to be when she was a child. She said that when she was little, she and her siblings made an adobe play house that lasted for years; but now it's harder to get the adobes to stick together and be hard. She thinks it's because the soil is polluted.
When a lime plaster is added over the first layer of clay, sand, and straw plaster, it has to dry slowly, in order to be durable. One way to do this is to lay wet sheets over it while it dries; or one can sprinkle water on it periodically while it dries.
Ms. Jimenez believes that re-plastering should be done once a year. This was traditionally done when she was a child.