Test Results
Split Face Block parapet with flat concrete capstone - no overhang or groove under the stone, no flashing or drip edge –Wicker Park, Chicago
Missing Mortar, no Flashing or Drip Edge under Pre-Cast Concrete Capstone on leaking common brick parapet wall – Uptown, Chicago
1. Check IMI and CLT?
Mortar information?
UIC Moisture testing?
Field Testing of WickRight?
Parapets are the short walls that extend above a flat roof along the perimeter of a building. They are mostly decorative, but they also conceal rooftop mechanicals, like AC units, and provide privacy and safety for rooftop decks.
Parapets take a lot of abuse. They are exposed to wind driven rain and snow on all 3 sides - the interior, the exterior and the top.
2. Portland Cement
Most contemporary parapets were built with mortar containing Portland cement, which allows moisture to enter, but then traps that moisture behind it.
Using Mortar that contains Portland Cement on older common brick parapets and walls can cause leaks and damage the brick. Older brick buildings should be "tuckpointed" with lime mortar.
3. Renaissance Stone and Concrete Capstones
Contemporary parapets of Split Face Block, concrete block, or brick facade with block structural wall are often capped off (finished) with Renaissance Stone (which is pre-cast concrete) which are extremely porous.
Parapets built prior to 1980 are typically common brick and finished with limestone capstones or clay copings. Historic installations do leak, but they also breathe and which allows moisture to escape.
In addition, many Renaissance Stone capstones are manufactured with flat tops vs. pitched tops to shed rain quickly, an industry standard.
Many Renaissance Stone capstones do not have drip grooves on the bottom edge of the capstone. Drip grooves break the surface tension of water rolling down the front of a capstone and prevent water from rolling back toward the wall and absorbing into it.
All capstones should have a metal drip edge and mason's flashing installed underneath. We evaluate wet walls everyday with neither. These walls are essentially open to the sky.