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Troubled Houses - The Home Owner's Resourcesm - Windows

We see many interesting adverse conditions during our inspections, partly because of the unlimited number of ways people can mess up a house, but also because we do a thorough inspection to reveal these adverse conditions. We hope these stories help home owners avoid these costly conditions by learning about causes, preventions, and remedies. A home purchase can create opportunities for the new owner to improve the home, possibly increasing its value, durability, and usefulness.

NOTICE TO BUYERS & SELLERS: This site does NOT encourage or discourage the purchase of any individual house, or style, age, location, or condition of house.  Conditions shown and/or described in the following articles may have been remedied at the house where these conditions were found.  These conditions typically can be remedied by qualified contractors. The presence of these conditions in any house is comparable to any other real estate consideration such as price, size, or location.  Consult a qualified home inspector before purchasing any house, and consult a qualified real estate agent for more information on how to handle a real estate transaction where adverse conditions are reported in a home inspection.   This site does not describe any house by address or knowingly show a readily identifiable exterior image.  Further, no home actively listed for sale  will be described on these pages at the time the article is posted.

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"Troubled Houses - The Home Owner's Resource" is a SERVICE MARK of Hankey & Brown Inspection Service Inc.  Click here for the list of topics and all articles in this resource.

Window Topics

Inspection necessary      Benefits from inspection    Window Condensation

Inspectors must open some windows. 

 (In the HOUSE, as well as on their computer.)

The windows in this 16 year old house suffered from condensation damage and poor design which lead to extensive water damage.  Our first indication of the condition was by viewing the wood sash around the glass from the interior.  There were condensation stains at the bottom of the window.  Opening the window sash revealed more damage.

                     Troubled Houses photo of decayed sash of awning window 16 years old.  Photo by Roger Hankey ASHI Certified Inspector in Winter Park, CO

Once this condition was observed, a more intensive investigation of the windows was undertaken.  We learned that the window frame was clad with a thin layer of plastic that was loose at the outer edge and ends.  Stains on the window frame suggested water was moving under this layer of plastic.  Lifting the plastic revealed extensive decay in the window frames of many windows.  Sash replacements would not suffice. Full window replacements were advised. 

  Troubled Houses photo of decayed frame of casement window 16 years old.  Photo by Roger Hankey ASHI Certified Inspector in Winter Park, CO

We were referred to this customer by their real estate agent.  The customer elected to hire an additional inspector in case we would not identify major concerns. The second inspector arrived as we were leaving. Unfortunately, the second inspector did not identify any major concerns, and said the windows were not a concern, even after prompting by the agent and customer.

The lesson here is that a ASHI® certified inspector must open windows for you to get a thorough inspection.  An inspector that doesn't open blinds and curtains will not even see the windows fully, let alone open them.

                                Small finding - Major benefits

This modern home had typical vinyl siding, and vinyl clad wood double hung windows. Our inspection included a close view of the windows from the interior including window "M". 

               (C) 2011 Modern house with mushroom in corner of window. Photo by Roger Hankey ASHI Certified Inspector, Winter Park, CO

5 year old vinyl clad wood window with fungal growth in frame. (C) 2011 ASHI Certified Inspectors, Winter Park, CO Detail of mushroom on 5 year old vinyl clad wood window with fungal growth in frame. (C) 2011 ASHI Certified Inspectors, Winter Park, CO
There was an odd feature in the lower corner of the window frame.  Upon close view it was determined to be fungal growth; actually a mushroom growing in the decaying wood window frame (behind the vinyl cladding). 

A few months after the inspection, the buyer's real estate agent informed us that the home seller contacted the window manufacturer who replaced most of the windows in the house.  Further, she stated that many OTHER home owners in this neighborhood of similar homes by the same builder have been notified of the sellers success, and many are also receiving new windows.  All this good news from the discovery of one little mushroom.  Early detection of the decay in these five year old windows may have prevented further damage to the wall structure below the windows.   Back to list of window topics.

                            Winter Condensation can ruin windows (and more)

Winter in Minnesota often creates conditions where the surface temperature of window glass drops below the dew point of the indoor air.  When this happens, condensation forms on the glass.  Condensation, is of course liquid water, which has the potential to damage almost any type of window AND grow mold on dust that can accumulate on the window sash. 

   (C) 2012 Window condensation photo by Roger Hankey ASHI Certified Inspector, Winter Park, CO
Notice that water is ready to drip off the lower right corner of the window sash onto the window frame.  Condensation in this case is consistent with high indoor relative humidity (high dew point). There are many human activities that can produce excess moisture in a house, but one of the most common causes is a center humidifier with a manual control not adjusted for cold weather conditions.  We recommend all central humidifier have automatic controls to adjust for changing outdoor temperatures.  Even modern insulated glass windows will produce condensation if indoor relative humidity is above 35% when outdoor temperatures are below zero F.

  (C) 2012 Fungal growth on a window due to condensation photo by Roger Hankey ASHI Certified Inspector, Winter Park, CO
This is a bathroom window.  The blackened areas near the glass are mold fungi growing in the dust on the window and in the paint.  Notice the wood shutter which has been opened for this photo.  This is a bathroom window and the shutters were typically closed and rarely opened.  A common cause of window condensation is the lack of indoor air flow across the glass to help keep the temperature of the glass above the dew point of the indoor air. This is particularly important in bathrooms which typically have the highest relative humidity in the house.  We recommended this window be cleaned with detergent ASAP.

We recommend the following actions to reduce the potential for winter window condensation: 

  1. Remove INTERIOR window screens (casement or awning windows) during winter.
  2. Keep blinds, drapes, shades, shutters OPEN during the day.
  3. Use bathroom vent fans at least twice as long as showers. (Install a timer switch.)
  4. Set the thermostat fan control to ON during cold weather to keep air circulating.
  5. Buy a digital relative humidity gauge to know interior humidity
  6. Never line dry or rack dry laundry in the house. (Modern clothes dryers can dry all garments without damage.) 
  7. Make sure storm window panes are closed or installed if removable.
  8. Keep window sashes clean by removing dust. 
  9. Wipe up any condensation and determine the source of excess moisture if condensation persists.  Constant problems with condensation can be caused by a blocked or damaged combustion vent serving gas fired equipment.  This can be a very dangerous condition and requires immediate attention from a qualified plumber or heating contractor.

Failure to limit window condensation increases the potential for peeling paint, wood decay, and structural water damage.  The earliest stages of these conditions are typically peeling paint on the sash of wood windows.
   (C) 2012 Peeling paint on a window due to condensation photo by Roger Hankey ASHI Certified Inspector, Winter Park, CO

Back to list of window topics.    Also see our moisture damage page.