Flashing refer to thin continuous pieces of sheet metal or other impervious material installed to prevent the passage of water into a structure from an angle or joint. Flashing generally operates on the principle that, for water to penetrate a joint, it must work itself upward against the force of gravity or in the case of wind-driven rain, it would have to follow a tortuous path during which the driving force will be dissipated. Exterior building materials can be configured with a non-continuous profile to defeat water surface tension.
Roof flashing is placed around discontinuities or objects which protrude from the roof of a building (such as pipes and chimneys, or the edges of other roofs) to deflect water away from seams or joints.
Wall flashing may be embedded in a wall to direct water that has penetrated the wall back outside, or it may be applied in a manner intended to prevent the entry of water into the wall. Wall flashing is typically found at interruptions in the wall, such as windows and points of structural support.
IBC Section 1405.3 requires: “Flashing shall be installed in such a manner so as to prevent moisture from entering the wall or to redirect it to the exterior. Flashing shall be installed at the perimeters of exterior door and window assemblies, penetrations and terminations of exterior wall assemblies, exterior wall intersections with roofs, chimneys, porches, decks, balconies and similar projections and at built-in gutters and similar locations where moisture could enter the wall. Flashing with projecting flanges shall be installed on both sides and the ends of copings, under sills and continuously above projecting trim.”
A building site (the grounds surrounding the structure) is a vital factor in providing for a moisture-resistant home. Assessing the moisture and drainage conditions at a home is perhaps the first and most important step in inspecting for a moisture-resistant foundation. Building foundations should be located on sites in a manner that prevents moisture problems by providing for adequate drainage of on- and off-site surface water flows, including roof water runoff. Groundwater conditions should also be considered during an inspection of a home with moisture-related problems. The foundation type, foundation elevations, and foundation moisture-resistant detailing are related factors that are dependent on a number of site characteristics.
Wetness of the site, soil-bearing conditions, and slope of the site are key factors in making a decision on whether to build and how to build the house. When poor site conditions exist, they can often be overcome technically, provided there are no land-use restrictions. However, the added cost of design and non-conventional foundation construction (such as an elevated foundation and/or special drainage features) should be considered important aspects of the expense of building a house. It is usually very costly to correct site drainage problems and foundation moisture issues after the fact.
Prevention of mold exposure and ensuing health issues include prevention of mold growth in the first place by avoiding a mold-supporting environment such as humid air. Extensive flooding and water damage can support huge numbers of mold growth. Following hurricanes, homes with greater flood damage, especially those with more than 3 feet of indoor flooding, demonstrated higher levels of mold growth compared with homes with little or no flooding. The aftermath of a hurricane is the worst case scenario, but the concept of water damage supporting widespread mold growth.
It is useful to perform an assessment of the location and extent of the mold hazard in a structure. Various practices of remediation can be followed to mitigate mold issues in buildings, the most important of which is to reduce moisture levels. Removal of affected materials after the source of moisture has been reduced and/or eliminated may be necessary.Thus, the concept of mold growth, assessment, and remediation is essential in prevention of mold health issues.
A common issue with mold hazards in the household is the placement of furniture, and the lack of ventilation which this provides certain parts of the wall. The simplest method of avoiding mold in the home is to move the furniture in question.
Adverse respiratory health effects are associated with occupancy in buildings with moisture and mold damage. Asthma can be aggravated or even induced with exposure to certain fungal species and some fungi cause skin infections such as athletes foot or ring worm.
Molds may excrete liquids or low-volatility gases, but the concentrations are so low that frequently they cannot be detected even with sensitive analytical sampling techniques. Sometimes these by-products are detectable by odor, in which case they are referred to as “ergonomic odors” meaning the odors are detectable, but do not indicate toxicologically significant exposures.
During you home inspection the Barrie Home Inspector will point out any deficiencies concerning drainage or moisture penetrations. Understanding the building envelope and drainage requirements is part of the Professional Home inspectors training.
