Wind Driven Rain

Wind driven rain can create leaks. Locating the source of water entry from wind driven rain can be very difficult. Sometimes water testing is needed to duplicate the leak and/or invasive evaluation to learn what failed or what was not properly installed.

While a roof and building exterior may last many years without water leaks, a very specific high wind direction during a rain storm will generate wind driven rain that can cause water entry. That water entry may not be immediately apparent but once it happens it will often get worse over time.

Generally there is an underlayment weather resistant barrier below the roof covering and there is a secondary or weather resistant barrier behind siding. All penetrations need flashing systems and windows and doors need drainage systems. When these barriers are not adequate or the flashing systems at penetrations are not adequate or when there has been some exterior damage that was not detected and repaired, water entry can result. Included in exterior damage would be flexible sealant systems that were not properly replaced before they lost their bonding and/or flexibility. All materials have a service life when replacement should be planned prior to failure.

Following a high wind rain event it is recommended to perform a general inspection of your home or building to identify obvious damage even if water entry is not known to have occurred. When water entry is detected it is helpful to note the time and date and all weather information such as wind direction, wind speed, and rate of rain fall. Photographs of each building side are helpful when performing these post storm inspections to record your observations. An exterior inspection is recommended at least once a year.