Vapor Barriers Overview

Vapor Barriers

• Vapor barriers are materials that slow down the rate at which moisture can move through a material.
• Vapor barriers are measured in units called "perms" or permeability.
• Vapor barriers help control moisture in basements, ceilings, crawl spaces, floors, slab-on-grade foundations and walls.
• There are three classes of vapor barriers defined by the International Residential Code:
  • Class I: 0.1 perms or less (Impermeable) - examples include glass, sheet metal, polyethylene sheet, and rubber membrane
  • Class II: greater than 0.1 perms and less than or equal to 1.0 perms (Semi-permeable) - examples include unfaced expanded or extruded polystyrene, 30-pound asphalt coated paper, plywood, and bitumen coated kraft paper
  • Class III: greater than 1.0 perms and less than or equal to 10 perms (Permeable) - examples include gypsum board, fiberglass insulation (unfaced), cellulose insulation, board lumber, concrete block, brick, 15-pound asphalt coated paper, and house wrap.

Bonding Agents

• Bonding agents are used to join individual members of a structure without mechanical fasteners.

Thermal Insulation

• Thermal insulation slows down the transfer of heat through a structure's enclosure.
• This can help reduce heat loss and gain from external or internal factors.

R-Value

• R-value is a measure of the material's resistance to heat flow.
• The higher the R-value, the higher the resistance to heat flow.

Insulation Types

• Fiberglass: Made from silicon, glass powder, and glass shards
  • R-Value: 3.1/inch
• Mineral Wool: Not combustible, but not suitable for extreme heat.
  • R-Value: 3.1/inch
• Cellulose: Made from recycled paper and cardboard. It is considered the most eco-friendly insulation type.
  • R-Value: 3.7/inch
• Polyurethane: Uses non-chlorofluorocarbon as a blowing agent and provides excellent insulation.
  • R-Value: 6.3/inch
• Polystyrene: Provides sound and temperature insulation.
  • R-Value: 4.0/inch

Moisture Protection

• Moisture protection involves materials that seal the exterior of a building against moisture intrusion.
• Moisture protection is also referred to as vapor diffusion retarder.

Epoxy Classifications

• Epoxy resins can be classified by type, grade, and class.

By Type

• Type I: Used to bond hardened concrete to other hardened concrete.
• Type II: Used to bond hardened concrete to freshly mixed concrete.
• Type III: Used as binders in epoxy mortars or concrete.

By Grade

• Grade 1: Consists of materials with low viscosity.
• Grade 2: Consists of materials with medium viscosity.
• Grade 3: Consists of materials with high viscosity.

By Class

• Class A: Used for systems that operate below 5°C.
• Class B: Used for systems that operate between 5°C and 15°C.
• Class C: Used for systems that operate above 15°C.

Sealers and Sealants

• Sealers are products applied to surfaces that help prevent water absorption.
  • Types of concrete sealers include: penetrating, acrylic, polyurethane, and epoxy.
• Sealants, often referred to as caulks, fill voids, gaps, cracks, and joints.

Roofing Systems

• Roofing materials deteriorate due to weather exposure. The rate of deterioration depends on the type of material and the environmental conditions.

Types of Roofing Systems

• Steep Slope Roofing: Used on roofs with a slope greater than 0.25 (1:4).
• Membrane Roofing: Used on roofs with a slope less than 0.25.