STUCCO NEWS.NET

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 most of the time. Most bricks made after 1920 or so provide an excellent base for stucco.

One problem is old bricks that are soft and porous. Mortar doesn't bond very good because there is too much suction. The mortar absorbs water too fast and will absorb the water out of the mortar instead of absorbing mortar into the brick. We use a bonding admixture in the mortar in this case.

Another problem is bricks that are slick. We usually chip up the bricks to make them rough and use a bonding admixture.

It is possible to nail metal lath to a brick wall by using long nails and angling the nails into the joints. This is what they did putting on Formstone years ago. Nowadays, people take off the Formstone and they can fill in the brick joints. When people nailed lath to the brick, usually the brick was broken up, and couldn't be restored.

I have found chemical bonders are better than using metal lath on brick, particularly painted brick.

If the mortar joints have badly deteriorated or the mortar has washed out, 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.

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:

http://www.rtbullard.com/stucco/progress/gooch02.htm.

Here is a job we did recently:

http://www.rtbullard.com/stucco/progress/progress110.htm.

The bricks here were a little slick on the surface, so we used 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 subject of a future article.