Building structures containing external vapor permeable foam insulation

Abstract

Attach a thermoplastic polymeric foam to multiple spaced apart structural support members of a structure wherein the foam has a resistance to water vapor permeability (mu) that is less than 50, a thermal conductivity that is less than 40 milliwatts per meter*Kelvin, a compressive strength that is greater than 80 kilopascals, and a density of 48 kilograms per cubic meter or less to provide insulation while also providing water vapor-permeability and structural durability to the structure.

Description

CROSS REFERENCE STATEMENT[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 022,915, filed Jan. 23, 2008.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to vapor permeable foam, methods of using such foam for insulation in buildings and building structures containing such insulation.[0004]2. Description of Related Art[0005]There is a need to increase the level of thermal insulation in existing building structures without inducing vapor build-up and condensation within the building structure.[0006]The European Energy saving directive of 2002 requires increasing insulation values of many building structures in European member states to lower energy consumption. However, it is critical to add insulation to these building structures without increasing the likelihood of vapor condensation within the building structures. Vapor condensation within a building structure can cause mold, mildew and decomposition of bui...

AI Technical Summary

Benefits of technology

[0018]The present invention has particular utility in insulating building structures by either building new or by adding insulation to existing structures in order to meet higher thermal insulting requirements and demands while avoiding hazards associated with retaining water within a building structure.

Problems solved by technology

Vapor condensation within a building structure can cause mold, mildew and decomposition of building structure components.

Typically, increasing the vapor permeability of a polymer foam decreases the foam's compressive strength.

Therefore, it has been unknown whether the objective of achieving an insulating foam that has a high enough compressive strength to support materials and workers without damage and that has a desirable thermal conductivity and water-vapor permeability is achievable with a thermoplastic foam.

However, the reference describes no properties of the foam.

Therefore, it is clear that decreasing the density of these foams reduces their compressive strength.

A foam with such a large cell size will have poor thermal insulating properties due to high convection of heat through the cells.