Proper Performance of Wood Flooring

Proper Performance of Wood flooring;

Moisture comes from a variety of sources-from the earth itself, from surface water (i.e., rain water runoff), as well as from the interior atmosphere. Let's consider the various ways that moisture problems originate, and how they can be controlled and prevented.With the introduction of engineered flooring, hardwood floors can be used in virtually every room in the house, even in basements.Water on or near the building site cannot be ignored or neglected.

A room that is exposed to excessive moisture would be prone to trouble if solid wood flooring were installed in it.Most complaints concerning hardwood flooring are related to changes in the moisture content of flooring and surrounding wood products.The effects of moisture on flooring. When moisture changes are severe, the result can be gaps between strips, cupping, buckling, movement, and/or cracks/splits in the flooring.

Potential sources of moisture;

NEW CONSTRUCTION:
During the building of a new home, moisture can enter the house in a number of ways. When the frame is going up, the 2-by-4s and subfloor materials often get rained on. Because builders usually work on tight, demanding schedules, homes are sometimes built trapping moisture that needs time to evaporate. The amount of moisture introduced by framing lumber and the wet trades can be significant.

GROUND WATER: Sometimes the level of the water in the ground is raised above the bottom surface of the foundation due to:

Heavy or prolonged rains;
a spring that appears only during wet seasons and is not discovered when the house was built; water flowing along an impervious layer within the soil.Any of these may cause water to penetrate the foundation walls or rise through the ground surface into the foundation or crawl space.

SURFACE WATER: Rain water falling on the ground or from the roof can pass through or under the foundation walls. In some areas, heavy soils may retain surface drainage and cause water pressure against the foundation walls or slab. Surface drainage problems may also occur because the crawl space is below the finish grade outside the house.

Wood is a hygroscopic material. This means when wood is exposed to air; it will dry or pick up moisture until it is in equilibrium with the humidity and temperature of the air. Moisture absorption causes wood to swell. Shrinkage of wood begins at 25-30% moisture content, the fiber saturation point, and continues until wood reaches 0% moisture content, an oven dry state. Conversely, swelling occurs as wood increases in moisture content from 0% to 25-30% moisture content, the fiber saturation point. Above 25% - 30% wood is dimensionally stable.

RELATIVE HUMIDITY: When humidity increases, the effect on the wood floor can be damaging. This occurs most frequently in homes in which occupants are there for a short period of time, such as a weekend home or vacation cabin, or in rooms that are closed off (not heated) to save energy.

If air conditioning or heating is not used or is shut off, ventilation is a must even when the home is not occupied. Otherwise, the floor will expand in the high humidity, and cupping and buckling will occur. This "greenhouse effect" will be exaggerated even more when a plank floor has been installed, because wider boards react to moisture with more movement.

Moisture problems associated with basements and below-grade features.Concrete appears to the untrained eye to be a solid, impermeable foundation,yet it's actually a source in itself for moisture.Concrete expands when it absorbs moisture in humid weather or by exposure to rain, and it contracts again when the moisture evaporates.

Minimum acclimation for solid wood flooring is one week.The acclimation period is required.True acclimation on real hard woods,not laminated will take many weeks.In the south east climate our humidity climate it could take two to for weeks.A solid wood floor is almost always installed with a moisture barrier between the subfloor and flooring to help control moisture.Wood flooringon the first floor will need longer to acclimate than flooring on a second floor level.