Stucco News

Question and answers on Stucco and Plastering
-- Aug, 2011

Stucco bonds fine to split face brick or block

We have a split face cmu house we recently moved into.  It's in Hawaii 
and in an area that rains a lot.
 Im already concerned about moisture penetration through the existing
hollow tile (CMU). I would like to improve the houses ability to keep moisture out.
My questions are:
 1. Can stucco be applied on to split face CMU without problem (any tricks
for making it bond well).
2. Will adding stucco help or hurt moisture penetration into house.
3. Are there stuccos with components
 or brands that make it more water impermeable- synthetic components?
4. How long will stucco last in wet area.
5. What would be the maintenance
 (paint every 2 years, etc?)

Thanks for any advice you have?
Stucco mortar bonds fine to split face brick or block.
 We applied stucco directly to rough concrete brick and it bonded fine without a bonding admixture.

I did a test patch on the back of the garage here:
When I went out to estimate the job, I put a blob of mortar on the wall, about 2 feet square, and about 3/4" thick.
I went back 2 days later and had to beat the hell out it to chip it. I was then satisfied mortar would bond fine.

If you look at the teeny pictures, you can see the split face bricks on the bottom floor. My web design skills
have improved since 1999,
so have web pages in general, but you can see what is going on.

If I had to do it again, I would use our half and half admixture in the scratch coat, for insurance
it would never fail.
I have an 18 second video on our acrylic mix here:

Stucco has always been used as an barrier against water intrusion.
It is still porous and absorbs water,but still far less porous than brick.

Using our half and half acrylic mix in the scratch coat  and the finish coat makes the stucco a lot less permeable, and reduces cracks as well.

This should last forever provided water doesn't get behind the wall.
The house should have good window sills, flashing, roof,etc.

The only maintenance if you use use a color finish is maintaining the color by cleaning. If the wall has
excessive staining due
to air pollution, or has a lot of cracks or spalling, the wall can be recoated, if it
has never been painted.