What Can We Tell from This Photo? (Case Study 14)

Posted by in Case Studies, Masonry | June 05, 2017

The feature photograph was taken of a chimney that had been clad with manufactured stone veneer.  This photograph provides helpful information regarding the cause and history of the damage.

From this photo we observe the following:

  1. There is no waterproof membrane installed behind the stone to protect the wood framing from the infiltration of surface runoff.
  2. There were not many fasteners through the plastic to hold the wire mesh and the mortar bed in place.
  3. The cement mortar encasing the mesh is very thin and provides a poor base for the stone.
  4. The joints between the stone are very wide and are susceptible to the infiltration of surface runoff.
  5. The wood framing has been exposed to excessive moisture repeatedly and for a prolonged period of time, as evidenced by the dark discolorations and the decay on the OSB sheathing and the severe corrosion of the fasteners and the wire mesh which have come off relatively cleanly.
  6. The well delineated pattern of the dark staining indicates there had been cracking in the stone veneer.
  7. The large fallen piece of stone veneer at the far corner indicates that the remainder of the stone veneer is in danger of falling off.  The owner was warned of this danger.

(Some of the observations above apply current construction standards to a manufactured stone veneer that was installed years ago.  Thus, some of these observations could not be used in the evaluation, but they are discussed here for educational and entertainment purposes.)