By Matt Blackmer and Rachel Schmidt, Higgins & Associates, Inc.
Preventative maintenance for water management around commercial and residential buildings is commonly overlooked unless an active leak is occurring from a roof or from a lower level basement area. Active water intrusion issues are primarily due to the lack of preventative maintenance on the exterior of the building. These overlooked conditions typically exist at the roof level in the form of roof covering or flashing maintenance, at the wall claddings (siding, stucco, etc.) due to a lack of sealant maintenance, and at the ground level due to a lack of surface water control.
Another problem area is the grading adjacent to foundation walls when improperly sloped and thus, does not provide for quick drainage of water away from the backfill zone. In addition to these flat or low-sloped areas, downspouts from the roof gutters are not always extended well away from the building and this backfill zone. Relative to preventative maintenance, flat or low-sloped areas of grading should be addressed to provide slope away from the building as required by the site-specific geotechnical (soils) report or as required by the International Building Code (IBC) or the International Residential Code (IRC), whichever is more stringent. For older buildings, the requirements of the IBC and IRC typically apply for preventative maintenance slopes. The IBC and IRC require a minimum 5-percent slope and specifically require that “Lots shall be graded to drain surface water away from foundation walls. The grade shall fall a minimum of 6 inches (152 mm) within the first 10 feet (3048 mm).”
In addition to addressing in low or flat spots in the graded landscaped areas adjacent to buildings, the roof downspouts should be adjusted, and downspout extensions should be added to discharge roof water at least 5 feet away from the building. Roof downspouts should not direct water over sidewalks or walkways to prevent icing during the winter and other potential slip hazards. Downspouts should also be adjusted to discharge well away from window wells or other areas where water could infiltrate to lower levels of the building. As part of preventative maintenance, water management around the building should be observed and repaired regularly as required to prevent water infiltration and other damages to the building and site components such as concrete flatwork.
Wall claddings should be observed regularly to assess and repair any necessary sealants at control joints, at window and door perimeters, and any other locations where sealants may have aged, pulled out, or otherwise failed. Flashings at windows and doors should also be reviewed regularly and repaired as necessary if damaged during the winter season by wind, snow, or ice. Regular maintenance of sealants and flashings at the wall claddings can help prevent windblown water from entering the building interior during rain events.
Similar to wall claddings, roof coverings, flashings, and gutters should be reviewed regularly and repaired as required. Gutters should be cleaned-out at least twice a year so that roof water is adequately drained off the building. We have seen numerous roof damage claims, including roof collapses, where the gutters were plugged with debris from trees and water and/or ice was allowed to backup onto the roof. It is also common for metal flashings to be pulled apart or otherwise damaged from snow and ice over the winter. These damaged flashing areas then become areas for water intrusion during summer rain events. Roof coverings, flashings, and gutter systems should ideally be reviewed at least in the spring and fall to provide ongoing protection of the interior building components from water intrusion.
With a regular preventative maintenance plan, building owners and homeowners can protect their properties from water intrusion with some basic and cost effective repairs. These annual reviews and repairs can help prevent potential significant damage if left unchecked. In an ideal situation, preventative maintenance can occur so that repairs are not only performed in response to emergency water leakage events.
Higgins & Associates, Inc. is a multi-disciplined forensic engineering firm providing the highest quality service to property owners, contractors, insurance companies, and attorneys. We offer comprehensive forensic engineering and expert testimony services specializing in the areas of structural, geotechnical, civil, mechanical and electrical engineering. Our firm also conducts cause-and-origin investigations of fire and explosion losses.
