Expert: Dan Griffin - 10/6/2007

Question
I had my house stuccoed and its been a week and I can rub it and it powders off somewhat, the person who did it said this is normal and when i paint it after another week it will be fine....is this true? thank you in advance. Nick

Answer
There are two toatally different products that get called stucco, so let's clear that up first.  There is a very old system that uses Portland cement, lime, is installed like plaster over chicken wire, and is hard like a plaster wall or sidewalk.  This is normally a 2 coat process, a base coat of gray masonry that is capped with a dash coat.  The dash coat gets the texture (many choices) and integral color.  There are many people who do not believe in painting a real stucco finish.

There is another newer system more correctly called EIFS (eefiss).  This is applied over Styrofoam in two coats.  The first coat is Portland cement with extreme amounts of latex acrylic modifiers installed as a very thin gray coat over nylon netting.  The finish coat is very thin and has the color and texture in it.

As you can see, I am a bit confused.  There are many cement block houses that have a decorative finish plastered onto the outside.  These are often painted.  All mortars are made from Portland, lime, and sand.  The finished product should be just like the mortar between bricks.  I would not consider it normal for it to rub off.  If there is a thin high peaked texture, the top edges might crumble a bit with  lots of pressure.  It sounds like it may have been too sandy or the wrong type of sand.  Perhaps you need the advice of a local competitor.  I would certainly discuss this with a commercial painter before painting.