Hugh Cairns: Irrigating crawlspaces

Crawlspaces can be a potential source of serious problems especially when water is concerned. Crawlspaces can be a welcoming home to moisture-loving pests like carpenter ants and termites, as well as health-jeopardizing problems like molds, mildews. Photo: Contributed – (Hugh Cairns)

Not every home is built with a crawlspace, but if you have one and an irrigation system it’s best to poke your head down there a few times a year to see what’s happening.

Crawlspaces are usually situated below grade and below the first floor of a home where construction trades can install necessary wiring, plumbing and ventilation components of the structure. Sometimes people use the crawlspace for a storage place for personal belongings, but storage blocks visibility that can conceal developing problems.

Anyone that has an irrigation system knows how they make watering virtually effortless. There is a lot of power in irrigation systems. They are under high pressure that is sprayed over hundreds and hundreds of square feet. The thing about irrigation systems is that they are usually at work in the wee hours of the morning when we sleep. By the time we get up they have already done their job, and sometimes more. Irrigation systems do a great job at watering, but they need periodic maintenance to make sure they are not broken and are spraying out of harm’s way.

If you’ve been on one of my home inspections you’ll know that I’m not a fan of irrigation piping and spray heads directly at the perimeter of the house, simply because of the damage they can cause. Far too often I see damaged siding and structural components. In the case of this house the soil along the side house was completely saturated. So much so that the irrigation system deposited enough water to travel deep into the crawlspace. This home is a great example why not to irrigate between houses when xeriscaping is a great alternative. My friends in the irrigation business advise that homeowners often water their plants and foliage too frequently. The general consensus is that it is better to water too much than too little.

Ponding water in the crawl space area has the potential to cause damage, structural problems and health concerns. Most homes in our area have heating; ventilation and air conditioning (HVAC) duct systems in the crawlspace. Should the crawlspace become affected by moisture related problems, the HVAC system can be a direct conduit to move unhealthy air into your home.