Ask the pros-June 2010
By Reggie Bullard
|Stucco over brick
we are a 4 story coop bldg. some of the bricks, especially along the top floor need repointing and water gets in when it rains. The bldg a long time ago had been stucco'd on one side of the bldg. we r getting quotes to repoint vs. stucco and have decided it is best to stucco...but one contractor is saying that we cannot use the steel mesh on top of the bricks because they cant stud deep enough? the other two contractors said they would clean put crumbling mortar between bricks repoint in areas as needed, apply wire steel mesh and then two coats of stucco... what is the truth about whether we should use a steel wire mesh on top of bricks? is it necessary?
You can stucco right on the brick. You can"t really nail metal lath to a brick. It does more harm than good. The bricks break up when nailed to. The only hope is to use long nails into the joints, and angle them in to wedge the nails in place. This isn't a very positive attachment, and will likely crack real bad.
All we do is force enough mortar in the brick joints to hold the bricks together when we put on our scratch coat, so there is no need for tuckpointing
As insurance of a good bond, we use a lot of acrylic in the mortar in the scratch coat. This is a necessity for very old soft bricks, or if the bricks are slick. Ther are some old fashioned methods of bonding mortar to old bricks, but I won't mention them here.
If there is any paint or tar, it should be chipped off.
Here is an example of old soft bricks that were deteriorated in spots:
Here is a job we did recently:
The bricks here were a little slick on the surface, so we
acrylic in the scratch coat. On newer bricks that are rough on the
surface, you can put the mortar without acrylic directly on the bricks
and have a very permanent bond, The bricks should be wet first,
preferably soaked with a hose. You also may expect a lot of
shrinkage cracks in the scratch coat that will look like a road map of
a mountainous region. This is normal, and the cracks will fill in with
the brown coat . You may reduce the cracking in the scratch coat by
adding additional sand to the mix, but this will be the point of a