A Typical Omission
ICC CODE: R703.1 General. Exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing as described in Section R703.8. The exterior wall envelope shall be designed and constructed in such a manner as to prevent the accumulation of water within the wall assembly by providing a water-resistive barrier behind the exterior veneer as required by Section R703.2.
Insulation and Vapor Barriers. Another important item that some builders omit is not installing a moisture barrier over the insulation. They claim it isn't necessary. The picture below shows the moisture content of stud cavities in a brand new house we were asked to repair. There was already black mold growing in the wall cavities and the house hadn't even been live in! The moisture penetrates the drywall and into the insulation and rots framing materials in the same way as omitting a housewrap.
36% moisture content
39% moisture content
Don't disappoint yourself with a problem builder. Spend the money to get the best, it is almost always cheaper in the long run!
Wrapping a home or building in a weather-resistant barrier is not just good sense, it’s good building practice and it is a code. Because it helps combat water, moisture and air infiltration that are any structure’s worst enemies. Allowed to penetrate behind siding, wind driven rain and moisture can saturate walls, creating a breeding ground for mold, mildew and wood rot. The properties of these house wraps do not support the growth of mold or mildew.
Air infiltrating from outside can create comfort-robbing cold or warm spots while increasing heating and cooling costs.
Housewrap acts like a windbreaker and wrapped over the sheathing and under the exterior siding—cut out around windows and doors and taped securely at the seams—resists air infiltration and water intrusion and makes for a more comfortable, energy-efficient home or building.
No worries with our homes! The housewrap is installed how it is supposed to be and where it is supposed to be. Everywhere, yes even on the garage and the gables.
You will see other “builders” not installing housewrap at all or not using it in the gables, or the garage, or yes even putting it under the sheeting! Sod is installed green side up and housewrap is installed over the sheeting!
The concept is simple, moisture will rot wood, housewrap prevents it! Oh, ICC code requires it installed the way we do it!
2009 Rapid City Business of the Year !
R. Chris Howie & Darin R. Howie
