Speak to a pro: 800-351-9563
  • FOR IMMEDIATE SERVICE CALL: 800-351-9563

  • Or schedule a time for us to call you back

Mold & Moisture on Windows - Causes & Solutions

Heavy mold growth on window

mold single pane window

Condensation is typical on a single pane window. However, proper ventilation can often eliminate moisture buildup

 

water and mold double pane window2

Heavy condensation on a double pane vinyl window requires extremely high humidity levels.

 

 

Heavy condensation on window

Heavy condensation on a double pane window indicates high indoor RH

Project Report > Mold & Moisture on Windows

Ventilation:

  • Adequate Ventilation Not Present
  • Recommended ventilation of residential homes should be between 0.35 and 0.7 air changes per hour (ACH).
  • Desired Ventilation Rate:  0.5 ACH (Air Changes per Hour)

Condensation on living room window

Recommendations:

  • Improve ventilation by one of the methods listed below:
  • Install ducted HRV (Venmar Constructo 1.0) in the utility room with registers placed in accordance with the diagram above, and all ducting run through the attic space.

Kitchen:

Moisture coming from kitchen window

Observations:

  • Major condensation noted on window.
  • Kitchen range exhaust hood not ducted to the exterior.
  • Minor surface mold growth noted on window sill.
  • RH:61.3% Temp:53.8°F CO2:2718ppm CO: 0ppm

Recommendations:

  • All condensation should cease once ventilation improvements have been enacted.

Living Room:

Observations:

  • Major condensation noted on windows
  • Moderate surface mold growth noted on windowsills and casing
  • RH:60.1% Temp:67.7°F CO2:2761ppm CO: 0ppm

Bedroom:

Condensation and growth on bedroom ceiling

  • No increased moisture content noted in building materials, except active condensation noted on ceiling.
  • Inspection with FLIR revealed major insulation defects in exterior wall.
  • Major condensation noted on windows.
  • Obvious dripping condensation noted on ceiling at exterior corner.
  • Significant visible mold growth noted on window sills and casings.
  • Moderate visible surface mold growth noted on ceiling at exterior corner.
  • Minor surface mold growth noted on baseboards at exterior corner.
  • RH:60.6% Temp:68.5F CO2:2786ppm CO: 0ppm

Bathroom

  • 110CFM Broan exhaust fan installed in this area.
  • Increased moisture content noted in baseboard and sheetrock immediately behind the toilet and adjacent to the shower.
  • Mold growth is likely present in this wall cavity.
  • Storage area sufficient to house an HRV located in this area
  • RH:57.9% Temp:69.2°F CO2:2840pm CO: 0ppm

Recommendations:

  • Install splash-guard to prevent further water damage to the walls.
  • Address wet building materials.

 Laundry Closet:

  • 40CFM nutone exhaust fan in this area
  • Minor mold growth around the laundry exhaust fan.

Got a question? Ask it here and we'll post the answer below