Leaking Renaissance Stone and Pre-cast Concrete Details

Leaking Limestone, Renaissance Stone and
Pre-Cast Concrete Details

Renaissance Stone Cornice and Details in Chicago's Lakeview neighborhood

Limestone, the traditional material used for decorative building details, leaks. As a natural material, it filters water through it slowly and the leakage typically isn't an emergency.

Contemporary stone products like Renaissance stone, which is pre-cast concrete, look like limestone – but it requires extra care to reduce moisture intrusion. It is extremely porous and one of the main entry points for moisture intrusion in newer construction.

Pre-cast concrete is installed everywhere you would expect to see limestone – parapet capstones, cornices, decorative details in brick work and around windows and doors.

One way to tell if your building has Renaissance stone versus limestone is to look for algae growth. While not attractive, algae grows on wet limestone because it holds moisture. It does not grow on Renaissance stone because the water goes straight through the stone and into your walls and roof system.

The jury is still out on whether or not Pre-Cast Concrete can be sealed successfully. It depends on who you ask. We say – not well enough to prevent moisture intrusion.

If a detail isn't structural – We remove it, flash behind it to divert water to the exterior of the building and away from other "stone" block and brick, reinstall it AND attempt to seal it.

If a detail is structural – We attempt to seal it, then if possible design flashings, cornices or awnings to divert rain water from hitting it or sitting on the structural detail.

Click here to see a vented sheet metal cornice we designed to protect a leaking pre-cast concrete cornice in Lakeview.

Scroll down to learn about Leaking Balconies, Railings, Doors, Windows and Roofs...