Moisture intrusion is typically noted as mold growth or moisture condensation on cold surfaces. When mold or condensation is limited to one localized area, the source of moisture is usually easy to determine. However, when the moisture intrusion is present throughout the structure, the entire building must be analyzed to determine the source of moisture and the conditions that led to its intrusion into the structure.

Moisture intrusion can originate as storm water leakage through the roof of a structure or through the exterior walls; or as ground water seepage through foundation walls or basement floors. These types of moisture intrusions typically do not require engineering analysis.

The moisture intrusion could be from hot humid outdoor air entering through leaky building envelopes and condensing on surfaces cooled by the building’s air conditioning system in summer time; or as warm moist indoor air condensing on the cold surfaces of uninsulated exterior walls and windows in winter time. The moisture could be from inadequate ventilation of high humidity areas like kitchens, shower rooms, and laundry rooms.

The moisture source could be from the HVAC equipment due to faulty components such as humidifiers, or condensate drip pans; lack of proper maintenance; improper design or installation; or oversized air conditioning equipment.

Webster Mechanical Engineering conducts on-site moisture intrusion evaluations, which includes thorough examinations and testing of the building’s envelope, HVAC systems, plumbing systems, exhaust and ventilation systems; evaluation of the building construction and layout; monitoring of outdoor and indoor humidity levels; and review of the occupancy usage to determine the source(s) of moisture and the conditions causing the intrusion.