Moisture Drainage Management

Moisture from rainfall can be a serious problem for many homes and buildings, particularly if it builds up behind the exterior cladding. Homes and buildings built in areas with high levels of rainfall each year – 20- to 60+ inches – can benefit from having a moisture drainage system installed. Many builders are aware of this fact, and are beginning to incorporate different practices to help manage and direct the moisture that may try to infiltrate the home. Homeowners may be put off by the initial expense of these types of systems, but installing them can help prevent larger, more costly problems down the road. There are numerous methods you can use to help with moisture drainage management from rainscreens to wall systems; each method has its benefits that can make it attractive to builders and homeowners alike.

Problems with Not Installing Moisture Drainage

Moisture drainage is gaining in popularity nearly everywhere, and in particular in those areas where rainfall is particularly heavy. Some areas have gone so far as to mandate that any new construction in the area install a rainscreen or some other form of moisture drainage management. For areas that see less than 60-inches of rainfall a year, however, many homeowners wonder if the expense is warranted.

For homes that do not have a moisture drainage management system of some kind installed, rainfall and moisture can become trapped behind the exterior cladding of the home. When this happens, the cladding, as well as the house frame, may begin to wick or absorb that moisture. Over time, this leads to softening of the wood, as well as to wood rot, and the growth of mold and mildew, which can eventually spread through the rest of the home. Installing a moisture drainage system helps prevent these issues, and can help maintain the home’s durability and integrity for longer.

While installing a moisture drainage system is more costly than simply installing house wrap and the exterior cladding alone, the cost of repairing the damage done by moisture is often much higher.


One of the most common forms of moisture drainage management is the rainscreen. A rainscreen is essentially a gap between the house wrap and the exterior cladding; moisture drains through this gap out weep holes installed at the bottom, preventing wicking and absorption of the water by either the cladding or the wrap.

Rainscreens are a very effective way of dealing with moisture, drainage, and rainfall. They can be customized to include larger gaps for areas with heavier rainfall, and can also include ventilation at the top of the system to help speed drying and air flow through the home’s exterior. They can be more time consuming and costly to install than other methods, but for areas of high rainfall, they often return the best results for homes clad in wood, brick, stone, and fiber cement.

Drainable Housewraps

A less expensive solution that’s growing in popularity amongst builders and that works well in areas that see fewer than 60-inches of rainfall a year is the drainable housewrap. This is a standalone solution to house drainage. Instead of installing a typical house wrap, then creating an air gap and drainage system, the wrap alone will facilitate draining, channeling moisture away from the house. No gap is required, and the exterior cladding can be installed directly on top of the wrap, speeding up the installation process and helping to keep costs down. Any home or building that sees more than 20-inches of rainfall a year can benefit from having a drainable housewrap installed beneath the exterior cladding.

Wall System

Not all homes and buildings are going to be built using materials that can facilitate either drainable wrapping or including an air gap. In these instances, using a wall system may be the better choice. In a wall system, drainage is obtained through the blocks the house or foundation is built out of, draining and channeling water directly through the walls, rather than outside of them. This system helps direct the water exactly where you want it to, away from the home and foundation and can help prevent issues such as standing water or flooding in areas with very high rainfall.

Wall systems have numerous other benefits in addition to moisture drainage; they are also fire resistant, help increase thermal insulation, are easy to install, and can support load bearing structures. They also include ventilation, which can speed drying of any moisture that does find its way in.

Install a Moisture Drainage Management System

Moisture drainage management may not be the first thing people think of when remodeling or building a home exterior, but including these types of systems can be beneficial in the long term. Consider applying an type of moisture drainage management system to help offset the problems caused by moisture and the damage it can bring.

Matt Lee 

Lead Generation Experts, founded in 2012, helps building materials manufacturers improve their digital marketing strategy.