A Proven Stucco System

Detail of modern metallic roof with snow guards on blue sky

With spring in full bloom and the struggles of shoveling 28 inches of snow as a dull memory, the most popular repair for chimneys this time of year is stucco resurfacing.   After a long and cold winter, the freeze thaw effect takes its toll on any masonry structure.  If a chimney has any type of small crack or defect in its surface, it has the ability to wick water inside of it’s mass.  When enough water is absorbed and the air drops to freezing temperatures it tends to pop or delaminate the face of a brick, cinder block, and or stucco finish.   This is usually when a homeowner notices pieces of brick or stucco laying on their roof shingles in the area of the chimney.

Usually when Tor chimney is hired to resurface a stucco Chimney or rebuild a brick chimney, it is at this time we recommend improving or correcting the two weakest points of the chimney.  The Crown and the roof flashing are the two areas, which are most overlooked and are the most prone to fail and allow water to enter the chimney.   A proper flashing job requires the use of step flashing which is installed under each shingle – scaling the pitch of the roof along the chimney.  The counter flashing should be cut into the chimney a minimum of 3/8 inch to form a mechanical seal between the metallic flashing and masonry veneer.  The step flashing prevents entry of water at the shingles and the counter flashing creates a waterproof seal from water shedding off of the masonry structure.  The crown or splay is located at the top of the chimney and is the area around the terra cotta tile.  This area develops cracks due to the flue tile expanding and contracting, bad design, and age of the chimney.  Once the top develops cracks, the water slowly works its way downward and slowly deteriorates the masonry.  The proper way to fix a cracked crown is to remove the old poured cement top and re pour a new one.  After the new top is poured and is dried slowly, the key is to seal the new top with a sealer call Crown Coat.  Once these two areas are 100 % and water tight, it is now time to resurface your stucco Chimney.

When resurfacing a stucco chimney it is import to clean and remove any loose or failed stucco that is laying on the surface of the chimney.  At this time Tor chimney install a vinyl Casing bead where the stucco meets any dissimilar materials such as vinyl, wood, cedar or aluminum siding.  All of these products will expand and contract, which will leave a gap between the two materials and will cause the stucco to fail again.  The vinyl casing bead that is used, captures and protects the stucco edge, while leaving an expansion joint where the dissimilar materials meet.  At the end of the job the expansion, joint is caulked to match the color of the existing siding.   Also where the stucco meets the ground,  a vinyl weep screed edge is installed to protect the bottom edge of the stucco and this will also not rust over time like the traditional metal edges know in the industry.  Once the chimney is trimmed out in casing bead it is now time to install our wire mesh.  The wire mesh is the structural base in which gives the stucco a mechanical bond to the existing surface.  Using Gas Powered Nail guns the wire mesh is nailed to the structure using masonry nails and washer system.  The Four coats that are applied to the chimney are known as the scratch coat, Brown coat and two stucco coats.

The scratch Coat is the first coat of mortar, which has the thickness of ½-3/8 of an inch.  The reason they call it a scratch coat is due to the deep groves or scratches that are scribed into the wet mortar with a tool know as a scarafier.  These groves or scratches provide and area for the brown coat to grab and key itself into and bond with the scratch coat.  During this whole process it is important to keep the area moist with a garden hose to ensure a good bond between the layering processes.  The next coat is the brown coat. The brown coat has the thickness of ¼ inch and once applied we use a tool called a Darby to smooth out this layer and even out the entire surface and square the edges. The last coat is the stucco coat.  The stucco coat continues to fine tune the last layer while giving it color.  It is at this time the homeowner chooses the desired finish for the texture of the chimney.   The added value the is instilled in the Tor Chimney experience is waterproofing the entire chimney.  We stand behind our work and the level of craftsmanship we bring to any job and this is why we give you a 15-year warranty on any full restoration job.

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