Building codes of some of the areas in America need the installation of rain screens. For instance, coastal areas of Oregon and British Columbia are among some of the places in North America where installation of rain screens is mandatory. The designs of the rain screen for the new manufactured homes will depend on the engineers and construction professionals designing and installing the home.
If you are planning to buy old manufactured homes for sale, it would be beneficial to understand the building codes of the area, as it will help you ensure that the home is constructed conforming to the local building standards. If the building code of the area calls for rain screen installation, then building to the standards will ensure successful installation of rain screens.
The basis of rain screen designing is the gap between the waterproof membrane, which wraps around the house and its outer sidings. This gap offers breathing space and helps to prevent moisture buildup inside the walls of the home. Buildup of moisture can lead to mold and mildew growth and other damages to the home. Most of the state building codes say that a gap of at least 10 mm (3/8 of an inch) is needed, but this may change with locality.
Regardless of that, there should be enough space for the rainwater to escape, allowing proper functioning of the rain screen. The building codes also need the capillary gap to be eighty percent open to avoid blockages and issues. This means that the furring or strapping materials need to the chosen carefully, so as not to close the capillary gap. Positioning the straps vertically will help to offer a clear path for the rainwater to drain. However, building codes have no moisture resistance requirements for the strapping materials that you choose.
Many manufactured home builders in the western coastal areas nowadays include a breathing gap at the top and bottom of walls as there is the added advantage of easy drying, although the building codes require only adding gap at the base of the walls. It is the discretion of the manufactured home builder to decide if the top of wall should be sealed or not. The state building codes restrict an opening at the top to the attic, roof, or the flooring due to the issues of moisture building up in closed spaces.