Winter Roofing Problem: Condensation

An often seen, but sometimes hard to diagnose, winter roofing problem is condensation.  It may look like a leak but when you look for anything capable of causing a leak, there is no cause to be found. Roof condensation problems can cause significant damage to the structure if not properly managed. While it’s always best to call a professional to learn about the mitigation options available, here’s some basic information to help you identify a potential condensation issue.

What Is Roof Condensation?

 Roof condensation is condensation that occurs on the underside of a building’s roof, or on structures located within the attic or crawlspace. It is no different than the condensation you might see appear on a glass on a hot, summer day. Condensation is often caused by improperly installed insulation. When there’s too much insulation, it tends to trap warm air near the roof, causing condensation. It can also stem from improper installation of vapor barriers, the roof, insufficient ventilation, or excess moisture in the building.

A normal household produces moisture from cooking, showers, laundry, and various other activities. During the day, especially in the warmer months, the heat causes this moisture to evaporate and rise. If the ceiling or attic space is not properly sealed, that vapor will travel up past the ceiling and become trapped in the space between the insulation and the roof, where it can be as much as 50 to 70°F (10-21°C) warmer than the rest of the house. If the insulation is improperly installed or the attic is not properly ventilated, the moisture will not dry out completely. As the attic cavity cools during the night or in winter, the water condenses or turns from a vapor back into a liquid.

Issues leading to roof condensation usually occur in winter and early spring when temperatures are cold.  When condensation develops in attic spaces and is trapped in that area, it creates a risk of damage to all of the material it comes in contact with, including the structure itself.

What to Do About Roof Condensation?

Prevention is one of the best roof condensation solutions!

First prevent moisture from entering from the outside, by fixing all leaks or potentially leaky areas. The areas around HVAC ducts, chimneys, attic hatches, and top plates should be sealed. In addition, it’s important to have bulkheads, drop ceilings, and skylights properly sealed (and inspected for any signs of damage or leaks). Even small holes, such as those from wiring or plumbing, can pose a problem. Have a professional seal them all!

Having the roof and attic inspected and maintained by people experienced in ventilation and condensation is the best way to deal with roof condensation. If damage has already begun, there are several ways of dealing with it, depending on what the root problem is. Ventilation systems should be checked to make sure they haven’t been sealed, more ventilation may need to be added as well. If there is a foil barrier over the insulation, this may also need to be cut back in spots to allow better breathability. Contacting a home performance specialist to do an overview of your home is a great place to start, if you begin to notice condensation issues.

Homeowners may reduce the moisture by installing dehumidifiers, keeping the fans running, and allowing spaces to have adequate airflow. The attic or ceiling may also benefit from being resealed with a vapor retardant paint or barrier so that the water doesn’t reach the roof. Generally, this is not considered a do-it-yourself job and is best done with the help of experts in roof condensation and ventilation.

Roof condensation in winter is not uncommon. It can happen to both newer and older homes. This is not a DIY issue, homeowners with condensation concerns should reach out to professionals who can apply the best roof condensation solutions for each individual home’s unique needs.

If you are worried about roof leaks, please do not wait to get help. Moisture in the attic can lead to structural damage as well as the buildup of mold. A weather-tight home that’s properly ventilated is one that is safest to live in!

Horch Roofing is Maine’s trusted roofing contractor. We have been roofing homes from Kittery to Castine since 2003 and serve the communities of Maine from our offices in Warren and South Portland. We have a dedicated Northern Maine sales estimator serving Hancock County and Bar Harbor. Horch Roofing installs standing seam metal roofing, asphalt shingle roofing, EPDM rubber roofing, and seamless gutters for both residential and commercial roofing projects. We offer free roofing and gutter replacement estimates. You can call us at (207) 273-1111, or contact us online.