How to kill the block joints

Ask the pros-January, 2003
By Reggie Bullard


When we stucco on block, you can see the block joints.
How do you kill the block joints ?

Killing the block joints on stucco
Rule one: Don't rod a block wall up. Only side to side.
You can't see the block joints on any of my jobs. Period.

This is not a do it yourself material. Plastering should be only done by qualified
Killing the block joints on stucco
After scratch coat sets hard(overnight for stucco),
brown coat may be applied.
Screeds are set with a rod or a string line. Wall is filled in between the screeds. Wall is then rodded side-to-side. If not, you will see the block joints.

I learned this trade under old people who were real demanding. For years, I worked on schools and hospitals, plastering on block. Plaster on block has been a preferred choice for years on walls that have to withstand abuse.

The scratch coat on plaster must set hard (about 2-4 hours), before apllying the brown, or double up coat. On stucco we always let the scratch  coat set overnight.I had the good fortune of working under old plasterers that taught me right.
Plaster is about the same as cement mortar (stucco mortar), except cement has a mind of it's own. 

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