What Can We Tell from This Photo? (Case Study 15)

Posted by in Case Studies, Mold Growth, Roof | July 31, 2017

The feature photograph was taken of the underside of a roof deck in an attic.  This photograph provides helpful information regarding the cause and history of the damage.

From this photo we observe the following:

  1. The pixelated pattern of the apparent mold growth indicates that the moisture promoting the growth is the condensation of excessive airborne moisture.
  2. The apparent mold growth and the checks (short surface splits) on the underside of the roof deck indicate that the attic ventilation is not adequate.  The apparent mold growth is from the repeated condensation of excessive airborne moisture during the cooler months and the checks are from excessive drying from excessive heat during the warmer months.
  3. The light staining on the wood exposed at the splinter where the nail was removed in combination with the darker staining on the underside of the deck indicates that there was condensation and apparent mold growth before the nail was driven through the deck and that the condensation and apparent mold growth have continued after the nail was driven.
  4. Relatively clear appearance of the wood exposed at the splinter where the nail is still present in combination with the darker staining on the underside of the deck and the corrosion on the tip of the nail indicates that there was condensation and apparent mold growth before the nail was driven through the deck and that the condensation and apparent mold growth have continued after the nail was driven.

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