CHIMNEYS AND PARAPET
■ Expose to the elements, such as wind, rain, frost, etc.;
■ Not exposed to a heat source;
■ High level of saturation.
Chimneys and parapets have the particularity of being strongly exposed to the elements, such as rain, wind, as well as being exposed to a large number of drying-wetting cycles during the cold periods and this without much protection.
In the assembly, one of the main role of the masonry joint being to be the first rampart against rain infiltration, it is therefore imperative to select a mortar that will offer the most protection possible against water infiltration, without being discharged of its responsibility in managing rainwater in relation with the masonry units. CSA A 179 standards mention that, for the construction of chimneys and parapets, it is necessary to use a mortar offering high compressive strengths since these types of construction are exposed at high levels of saturation. This declaration is also valid as part of a restoration project. So, be sure to select a mortar with greater compressive strength for restoring your chimneys and parapets compared to mortar selected for repointing walls.
Chimney and parapet tops are particularly sensitive to water infiltration. For this type of application, we recommend the mortar: King® Reconstec MF