Moisture Issues in Homes

If you have ever lived in a newly constructed home, you surely know that during the first months to a year of occupancy, as the various systems, plumbing fixtures and appliances are operated and the natural drying of many of the materials used to build the home occurs, you may notice cracks or other irregularities forming in walls or ceilings or even floors. This primarily occurs as the wood elements that make up the framing of the house are subjected to their first thermal cycle - expanding and contracting with changes in moisture or temperature.

This is often most noticeable as the heating system is used, accelerating the normal drying process, causing the wood to shrink and warp a bit. Sometimes even noticeable sounds can be heard as the cracks open up or components move. Small bumps may occur on surfaces of the drywall as the fasteners loosen or are forced out slightly. Dimples may occur as warpage of the wood pulls secured fasteners back from the surface. The more common use of drywall screws has help minimize the potential for "nail pops," however, most new homes will still experience some evidence of this condition. In any case, both dimples and pops are cosmetic issues and relatively easy fixes in most cases.

The drying and shrinkage of wood over time also causes cracks to form, particularly around windows and doors and other openings where the pieces of framing are different sizes or have different orientation. When wood dries, it can also warp, which contributes to cracking, especially along the length of long members such as ceiling or floor joists. Another characteristic of drying wood is that it dries from the outside inward. As a result, where exposed, you may see some crack or chip on the surface, particularly around knots or other irregularities.

As the wood and other building components dry out dry out, they actually add moisture to the house air. While excess moisture is not wanted, a certain amount of moisture is beneficial to maintain a reasonable level of humidity inside a home. Maintaining the acceptable level in any home can be difficult, but can be even more of a task in a newly constructed home, or even an older home recently occupied by a new family with different living habits or lifestyles. Cooking, bathing, or even just the presence of people in a house adds additional moisture to the house air. Moisture from a damp crawlspace and basement can also add significant amounts of moisture to the living area.

The normal opening and closing of doors helps prevent the buildup of excess moisture. However, in some cases mechanical venting will be required. A new home may have a whole-house mechanical ventilation system designed to maintain an acceptable level of moisture by exhausting stale air and drawing in fresh air from outside. But even with these systems it can be difficult to maintain the appropriate moisture level.

If excess moisture is not vented properly, it can cause problems such as mold growth, especially as it mixes with other common sources of moisture in a house. If it is the winter season and the windows are very cold, this indoor moisture may show up as condensation on the cold surfaces. Bay windows, due to their projecting design, or north-facing windows, are generally more prone to moisture condensation than other windows.

Exhaust fans installed in kitchens and bathrooms vented to the exterior also help control the level of indoor moisture-laden air. Venting clothes dryers to the exterior is always required to expel the significant amount of moisture-laden air produced during the drying process.

If the moisture level falls too low, you may find yourself with stuffy nasal passages or the victim of annoying shocks from static electricity, particularly when heat is provided by a forced air or electric heating system. Cracking in wooden furniture and dried out skin are other effects of dry air. A properly set and functioning humidifier can help maintain a proper relative humidity level; but if improperly set and maintained, the exc3essive moisture can create significant problems.

If you find you are unable to control your indoor moisture conditions, contact your HVAC service provider or an indoor air specialist for an assessment. Sometimes the source of indoor moisture problems can be difficult to determine without an extensive evaluation; but in other cases, an inspection by a qualified professional can provided a simple solution.  Be aware of these signs of improper moisture in your home.  Simple corrective measures will lengthen the longevity of the building components and will improve indoor quality of life as well.