The primary purpose of housewrap (Tyvek) is to:

A. reduce the likelihood of ice dams.
B. channel water to weepholes make exterior siding easier to install.
C. reduce air infiltration/drafts increase the insulation value in the exterior walls.

reduce air infiltration/drafts

Correct Options:

reduce the likelihood of ice dams. channel water to weepholes make exterior siding easier to install. reduce air infiltration/drafts increase the insulation value in the exterior walls.

Explanation: Housewrap is a material, usually polyethylene as is the case in Tyvek. It is used in building construction in the finishing stages and serves as a protective covering. It is designed in such a way that it prevents rain water and drafts from getting into the wall but it allows vapor to escape the walls. This reduces air infiltration and ensures that the wall stays dry.  

Tyvek is a type of housewrap and is a registered trademark of Dupont.

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