Diverting water away from your home is important, because of the damage water can cause. Splashguards are a common method to achieve this goal.
Here is a quick post on the problem with splashguards. I have read a few reports by other home inspectors where splashguards at a downspout were considered unacceptable. Builders seem to love them; I think because a splashguard is cheaper than a tube. My best advice is that when installed correctly in the right location, a splashguard can serve its purpose well. I bet you are wondering about the “installed correctly” statement. Look at this photograph from one of my home inspections.
Turning the splashguard around the wrong way is more common than you might think. I have seen crews at new home construction sites leave them facing the wrong way. The open end should be out, so the water can flow down and away from the home. That is why the splashguard is designed with a pitch. When facing the wrong direction, the splashguard collects water, which is not good for our mosquito infested area. However, this splashguard helped keep more water by the home by not creating a flow. In the picture you can see the ground around the splashguard effected by standing water.
What did I mean by “in the right location”. I have a problem with gutter systems on many homes. I do not feel that anyone sits down to think about how we are getting water off of the roof, down to the ground, and then away from the house. If you have a gutter downspout pouring water onto the ground at the side of the home, and if the grading will naturally force the water to the street, then having a splashguard at the base of the downspout works fine. Water coming out through the downspout can wash away the grading at that spot, and the splashguard helps to prevent that deterioration, so the grading stays in place. For the grading to move the water away from the home, the ground level has to be higher at the house, and then slope down to the street. If your grading allows water to pond near the home, you need more than a splashguard. The solution becomes attaching a diverter tube to the downspout that can direct the water away from your home’s structure. The rule of thumb is that water should not collect within five feet (at the minimum) of the foundation. The grading can also not be too high against the foundation. The ground will hold moisture that can effect the home’s walls, and insects can be an issue (termites create tunnels from the ground into weepholes; they want this distance to be short, so that they will not be seen).
A splashguard may seem a simple thing, but it can lead to problems. Take a look at your own to see that they are not causing issues.