Stucco chimneys

August, 2001
                chimney cap old brick
                chimney was stuccoed.
Look at an old stucco house. It's usually in good shape except the chimney. The cap, which is mortar spread on the top of the chimney, cracks, spalls and deteriorates.
The water damages the stucco, which should last forever, provided a lot of water doesn't get behind it. Solution- check your cap every 5 years and coat over if needed.
Here an old brick chimney was stuccoed.
The bands at the top were added. These not only add a decorative effect, but prevent water from running down the face of the stucco.
                chimney Metal cap
                on chimney
EIFS chimney before we tore off the EIFS and put on new OSB. The same details will be duplicated with stucco (cement mortar).

The sheathing was badly rotted but the
framing was still solid after it dried out for a few days. We added some additional bracing to support the stucco.

Metal cap on new house leaks bad. The metal is secured with nails covered with globs of caulking. The caulking has cracked up and shrunk allowing water to enter 6 year old chimney. Where my fingers are is another caulk joint which has shrunk and cracked allowing water to enter between the EIFS and the metal cap.
We covered
the cap with lath and mortar. These metal caps are a joke. They leak and allow rust
stains to run down the chimney.
                on chimney flashing
                on chimney
View of side of chimney showing the original step flashing and a kick-out flashing we made. The kick-out diverts water from the flashing into the gutter. These are critical in preventing water from running behind the stucco.
The step flashing was in good shape so we re-used it. Most of the sheathing
was rotted and had to be replaced.
Step flashing is sealed with black stuff
from Home Cheap-o.
This is the same black stuff that comes in a can and gets all over the place. I felt
that in a tube, it wouldn't get all over the place.
                on stucco chimney lath on
                stucco chimney
Counter flashing is bent with a metal brake to cover the step flashing. The counter flashing prevents water from getting behind the step flashing. 3/4" plaster stop (casing bead) is butted to  counter flashing. This defines an edge for the bottom of the stucco and defines the
thickness. The flashing is covered with red tape and plastic before stucco mortar is applied.
Tar paper and self-furring lath are applied to the chimney.
                chimney stucco
                chimney cap
Juan C. rods off the brown coat while
Edgar rubs the mortar with a float after it sets.
Scaffold-cam shows 2x4 forms nailed to the chimney to define the first step. The band has an additional layer of metal lath and a scratch coat applied.

The metal cap at the top is covered with
metal lath and a scratch coat.

                chimney cap stucco
After the first layer sets, the next step is
formed and filled, then the last step is
formed and filled.

I had pictures of each step, but they got
deleted by mistake. I hope you get the


Finished chimney with white portland and white sand. The top is slightly rounded to allow water to run off.
The three steps at the top add a nice
decorative as well as functional effect.
Note the decorative band 2 feet below the steps. This was formed with 1x4 s and filled with lath and mortar.
The cap (the very top) will need to be
checked every 5 years for spalling or
deterioration and recoated as needed.
It sure beats that metal that was there.