Frost On Underside Of Roof Sheathing

Picture a cloud of moisture floating overhead between the rafters.

Frost on underside of roof sheathing.

Essentially condensation occurs at night when the temperature inside a building is warmer than outside. Combine 1 2 cup chlorine bleach with 1 gallon of water and use a sponge or cleaning brush to scrub the mold. Frost on underside of roof sheathing it s more likely a vapor problem than a liquid water problem. The frost itself doesn t do any damage but once it melts things get wet which is when the damage.

This latter phenomenon occurs when the house is too humid and the warm moist air seeps into the attic where it condenses and freezes on cold attic areas. That excess moisture ends up as drops of condensation on the roof. After several years of this there may be. When it reaches the cold surface of the roof sheathing and framing it turns to frost.

In the parlance of building scientists these cold wooden house parts make up a condensing surface much like a cold glass of ice tea beads with water on a hot summer day. When the moisture gets into the attic it condenses on the roof sheathing in the form of frost. You definitely don t want frost in your attic. He wondered if that could be the cause.

A little bit of frost forming is not unusual after really low nighttime temperatures and it isn t a huge problem if it is able to melt and evaporate so that the wood can dry. Frost and ice forms in attics when warm humid air accumulates and condenses on the underside of your roof sheathing. Can sun get to the roof you will have either frost or water collecting. Water vapor is migrating upward and eventually filtering into the attic.

The problems you pointed out are certainly real and need repair but getting the underside of the decking frosted requires vapor. Frost itself doesn t do any damage but once it melts things get wet and then damage occurs. Melting frost can lead to deteriorated roof sheathing mold on the roof sheathing wet insulation and water stains on the ceilings. Warm wet air rises and meets the cold roof and cools.

As it cools it can t hold as much moisture. Don t rinse or wipe the bleach solution from the sheathing after cleaning. He recently had a new heat pump and aprilaire humidifier installed in basement.