Parapet is actually the part of the wall which goes above the roof level. Since the inner and outer walls of the parapets are constantly unprotected from heavy rain and drastic changes in the weather’s temperature, they are quite vulnerable when it comes to water and thermal issues. Therefore, all sorts of careful planning are needed during parapet wall construction. Regular maintenance is a must as well.
One of the more common ways to prevent water from sipping through the walls via its joints would be to extend the flashing through the parapet wall completely and have its ends bent so that it forms a drip. This form of parapet wall construction is done by installing a continuous wall-penetrating flashing under the mortar bed, which is directly under the cap.
Aside from solving the water issue, the thermal problem could be solved by fixing in twice the number of expansion joints within the parapet as the wall below it. Besides, putting in a soft joint for each part of coping stone has the function of preventing coping misalignment and failure in the joints. All these are necessary during the construction as the parapet wall tend to contract and expand at a faster rate when compared to that of the masonry underneath them. This is due to the fact that parapet lacks the heavy load or burden which the masonry harbor and serves to restrict movement.
Going on, because of differential movement between the masonry and the structural steel frame work, parapet walls can at times be affected by displacement. Hence, in order to accommodate this differential movement, the masonry wall should very well be connected to the steel frame with a flexible anchor at the spandrel beam when it comes to parapet wall construction.
In conclusion, the building of parapets should not be taken lightly as the slightest mistakes might cause cracking on the walls. It is particularly important for constructors to go along with the Building Code Requirements so as to manage the quality of their works.