Normal Moisture Levels In Attics

Mostly because there are many misunderstandings of what is an appropriate level for wood moisture levels especially in the crawlspace.

Normal moisture levels in attics.

The acceptable moisture content in wood depends on two factors. Outside air moves into the attic leaves its. Wood moisture content is the weight of water in a piece of wood expressed as a percentage of oven dry weight of wood. This creates the perfect environment for mold and mildew to form.

Fresh cut trees can have a wood moisture content over 200 while completely dried wood will have a wood moisture content of 0. Why is this important to understand. If you raise the attic temperature the rh in both places would be the same. The normal indoor humidity range in winter should be 15 to.

In the wood scale the meter can detect moisture accurately over a range of 6 mc to 40 mc. If looking at an attic at a 110 degree f temperature and 80 relative humidity the wood moisture content would correlate to a 14 7 wood moisture content. By adding moisture to the lower floor you increase the partial pressure of the water vapor which pushes it to areas of lower vapor pressure like the attic. During the winter months the recommended relative humidity inside a house is anywhere between 30 50 percent.

The acceptable moisture levels of wood and lumber are in the range of 6 to 8 for interior and 9 to 14 for exterior wood or for building envelope components within constructed assemblies. The short answer to this very involved question and the pages of temperature and humidity level data you sent is yes there is a risk that moisture from humid air in your attic will condense on. The difference in the two spaces is the dry bulb temperature. If there is excessive moisture accumulation in your attic it will condense on cold areas mainly on the underside of your roof deck.

Humidity settings are another issue that can make or break the performance of your heating and cooling systems and your attic ventilation. The wood s final use. So they equalize pretty quickly. Wood in buildings usually has a wood moisture content of 5 to 15.

The average rh of the environment where the wood will be used. This easy to follow diy guide will show you how to monitor your attic s heat and moisture levels so you can afford these problems. Even in winter condensation can be problem if the attic is too warm.