Stucco News

Question and answers on Stucco and Plastering-- July, 2013

          Cement stucco on adobe blocks

  I have been asked about
bonding cement mortar to adobe (dried clay) blocks.

I haven't ever worked with adobe, but I have heard this from people from Central America,
where adobe is still used a lot. Don't laugh at adobe. Adobe is almost earthquake proof, has
excellent thermal mass, and is as earth friendly as a building material can be.

Adobe is essential is restoring historic buildings in the Southwest and other places.

Here's the mystic secret:

Before stucco application the adobe blocks are splashed with lime, that is a soupy
mix of lime and water. The lime soaks into the surface and hardens the surface.
After the lime dries, it is real porous creating good suction for a bond with cement mortar.

I haven't ever done this, but it seems real credible to me. Also, I heard about the lime
trick from reliable sources.