Attic Problems

Attic Problems

Building Type: Residential Home

Primary Complaint: Attic Problems

Project Number: 103062

Relevant Project Info:

  • Inspection of attic revealed mild to moderate mold growth in isolated areas of attic sheathing.  Much of the mold growth is limited to a white powder which does not leave residual staining on any of the wood.  The white mold growth is found both on some surfaces of the attic sheathing as well as the truss webbing.
  • Some isolated locations of black mold staining were discovered on the roof sheathing in only one of the three attics inspected.
  • At this time, the mold growth has not lead to significant structural damage of the underlying materials. However, the mold growth may be a health concern and is an indication of a failure of the home to adequately exhaust damp air created by the occupants.


  • All attics appear to require a mildicide treatment throughout the attic space.  An EPA registered mildicide would be applied to the attic sheathing, framing and insulation via an Ultra Low Velocity (ULV) fogging system.  This will effectively kill all mold growth and dissolve away any three dimensional or powdery mold growth.  All existing mold growth will effectively cease from that point forward.
  • Some attics contain dark or black colored mold growth on the attic sheathing.  An application of the mildicide will effectively kill this mold as well, but the treatment will not remove the discoloration from the wood.  This discoloration is primarily an aesthetic blemish and normally has not affected the structural integrity of the wood, nor does the staining pose any potential health risk.
  • However, in the process of a home sale, home inspectors are trained to look for these discolorations and will make note of the discoloration even if the mold has been effectively treated.
  • Elevated moisture noted in isolated areas of the attic sheathing where roof leaks were discovered.  It is necessary to thoroughly dry the framing and sheathing prior to the application of encapsulant.
  • The average moisture content of the inspected attics was below 20% with the exception of any areas where leaking areas of the roof were noted.
  • Obvious roof leaks were noted in several places in the attics.  The builder is aware of these problems and has a plan to repair each of the areas of concern.
  • Insulation shows no signs of significant water damage, or mold growth.  Spores may be present in the insulation, and the insulation can be removed at the customer’s request, but once the recommended steps are performed the spores are unlikely to negatively impact indoor air quality.
    Attic Problems
  • Ridge ventilation varied from attic to attic in the inspection.  Multiple roof lines, gables and fire/sheer walls appear to create air flow problems that appear to affect each attic differently.
  • Inadequate ridge ventilation limits the exhaustion of humid air through the roof assembly.
  • Insufficient soffit ventilation was found throughout all attics inspected.
  • Soffit ventilation was blocked by improperly installed insulation.  This limits the influx of fresh air through the soffit vents, leading to excess condensation and mold growth

o    Multiple rooflines and gables block many areas where soffit venting could be installed.

o    Soffit baffles are improperly installed and/or missing in many locations.

o    Some gable extensions do not have any ridge venting.

o    Main attic area contains adequate ridge venting.

o    Fire/sheer wall limits amount of available venting in each attic.

  • Type B buildings:

o    All soffit venting is blocked due to improperly installed insulation throughout the vaulted areas of ceiling.

o    Insufficient ridge venting present inside the attic space

  • Proper ventilation is necessary to minimize condensation and subsequent mold growth.  All areas of improper ventilation must be addressed to ensure the effectiveness of our process.  Current code calls for 1sqft of ventilation for every 300 square feet of attic space, distributed evenly between the ridge and soffit area.


  • Type A Buildings:

o    Recommend installing additional soffit vents in every available soffit bay.

o    Remove and replace all damaged insulation baffles.

o    Remove all insulation found blocking soffit vents.

o    In locations where vaulted ceilings block the soffit venting, it is recommended that additional “ridge style” venting be installed along the lower edge of the attic space.

o    Ensure each gable area contains adequate ridge venting.

o    A powered ventilation fan may be needed in areas where adequate venting is not possible.  This option may not be necessary for every attic.

  • Type B Buildings

o    Traditional soffit venting is not possible in these attics. It is recommended that “ridge style” venting be installed along the lower edge of the attic space to provide the necessary airflow.

o    Additional ridge venting is necessary for each of these attics.

  • The ceiling currently lacks proper air sealing, allowing excess moisture and heat to escape into the attic area.  This air leakage is a key cause of energy loss, attic condensation and mold growth.
  • Type A attics contain one or more large chases (areas of connectivity between inaccessible interior cavities and attic space).


  • Recommend sealing all in-ceiling penetrations with a spray-foam insulation to limit condensation and heat loss into the attic space.
  • It is necessary to seal all chases with the appropriate materials to provide a continuous air and thermal barrier inside the attic.
  • The attics in Type B homes contain HVAC ducting which may not be adequately sealed, allowing conditioned air to escape into the attic, and attic air to enter the heating system.  The HVAC ducting in unconditioned space must be securely attached and sealed with high-velocity duct sealant to reduce heat loss and indoor air quality issues.
  • All ducting from ventilation fans are composed of corrugated, aluminum pipe and have excessively long runs to the exterior.  The corrugations and excessive length severely limit the effectiveness of the ventilation fan.
  • Many of the sections of corrugated venting exhibit severe crush points which greatly restrict airflow.
  • All ducting was attached with severely degraded duct tape.
  • All exhaust ducting from the bathroom fans are not appropriately venting to the exterior.  This condition allows warm moist air to flow into the attic and is likely a contributing factor in condensation.


  • Recommend all fan ducting be 4”, straight-walled, galvanized steel ducting.  Ducting must be secured to each fan using approved foil tape and each ducting joint must be secured using sheet metal screws and coated with mastic.
  • Recommend insulating all fan ducting after installation.
  • It is necessary for all exhaust ducting to vent completely to the exterior through insulated ducting and be connected to a dedicated roof jack with appropriately sized collar.
  • Evidence of past or present rodent infestation was noted, contaminating the insulation, requiring removal and replacement.  Rodent feces, urine, and other associated debris may harbor bacteria, parasites, and odors.
  • Evidence of past or present bird infestation was noted on the insulation, requiring removal and replacement.  Bird feces, nesting material, and other associated debris may harbor bacteria, parasites, and odors.
  • A pest control specialist is necessary to provide a plan to resolve the current infestation and prevent future pest infestations.
  • Significant amounts of trash and/or construction debris were noted in the attic.  This material must be removed to facilitate the necessary repairs and remediation.
  • The attic currently has walk-boards or make-shift flooring installed. These must be removed to provide access the cavities for insulation and air-sealing improvements.
  • The attic is currently free from excessive amounts of trash and construction debris.
  • Stored contents located in attic, it is necessary for these contents to be completely removed prior to the start of any remediation work.

July 15th, 2011 | Category: Attic Mold

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