Questions With Answers
True or False When temperature increases evaporation of absorbed water increases and
water vapor suspended in air also increases.
Classification of Water Intrusion described as Class 1, 2, 3, or 4. Must be determined to
calculate the amount of dehumidification required in drying process, based on the amount of wet
surface area, permeance/porosity of materials in drying area.
Class 1 is the least amount of water absorption and evaporation load, affecting less 5% of
porous materials with minimal absorption into low evaporation materials.
Class 2 has a significant amount of water absorption and evaporation load, affection 5-
40% porous materials, with minimal absorption into low evaporated materials
Class 3 has the greatest amount of water absorption and evaporation load, affecting more
than 40% porous materials and minimal absorption into low evaporated materials
Class 4 has deeply held or bound water, and significant absorption into low evaporation
materials.
Determine the Class of water for a 20' x 20' x 8 ' room, with an entirely wet floor..
Affected area/Total SF = % affected
, 400/1440 = .27777 x 100 = 28%
28% = Class 2
Determine the Class of Water for a 20' x 20' x 8' room, with only half the floor affected and
arriving within 24 hours of loss. Affected area/total sf = % affected
200/1440 = .13888 x 100 = 14%
14% = Class 2
Determine Class of water for a 20' x 20' x 8' room, with entirely wet plywood subfloor arriving
48 hours after loss affected area/total sf = % affected
Class 4 due to deeply bound water sitting for long time
Categories of Water there are four categories - determined by range of contamination of
the source and quality of water
Category 1 water Water originating from sanitary water source, with no deterioration,
does not pose risk to skin or if ingested
Category 2 Water Water containing significant contamination from materials, unsafe
levels of microorganisms, causes discomfort or sickness.
Category 3 Water Water grossly contaminated with pathogens, toxins, bacteria, causes
sickness