Ask the pros-June 2010
By Reggie Bullard
Block joints show through the stucco.
landscape contractor in the great NW. I hired a sub to stucco a block wall. The finish is sound and attractive except for one panel where the joints in the wall have bled through. What causes this? Thanks! We have eliminated the block joints showing as humps,
but haven't competely eliminated the joints showing
when wet. Our jobs are far better than the wall in the
picture. I already covered how to eliminate the block joints
showing through, by rodding off the wall from side to
side, between horizontal screeds. Please click
here. What I didn't explain is what screeds are, so I wrote
about screeds. Please
click here. The important steps to eliminating block joint are: 1. Allow the scratch coat on the blocks to set up
overnight. 2. Fill the wall out to an honest 3/4" 3. ALWAYS rod the wall side to side and NEVER up and
down. 4. Allow the brown coat to set up a week before
applying the finish coat. The picture in conidition 1 is an apartment building
in Reston, Virginia that was stuccoed in the early
70's. I know because I was working close by in that
time period. The picture in condition 2 is a well
known Washington, DC area restaurant. The sad thing
is, the color stucco looks like it was well done,
except the brick joints show really bad when they are
wet. |