Most people know to put gutters on their house, but they skimp when it comes to the detached garage. Just like your home, draining water from the roof can damage your garage or its foundation. Knowing the four main problems roof drainage can cause in your garage can help you make an informed choice.
#1: Under-Door Leaks
A combination of several issues can lead to a perfect storm under your garage door. A damaged or missing threshold seal, roof run-off, and the lack if a door seal are the usual culprits.
The simplest fix is to make sure the garage door bottom seal is in place and in good condition. It's usually a basic gasket that you slide into place. If water continues to leak in when it rains, the deluge may be dripping off the roof. This is especially a problem if the roof slopes toward the door opening. Installing gutters along the eaves will route the water away from the door and stop your flooding garage problem.
Thresholds are only necessary if your drive slopes downward to the door, so that neither seals nor gutters can stop it. You will feel a bump when driving over a threshold, but it's not high enough to damage a car.
#2: Soil Erosion
If you don't have gutters, you can likely spot the drip line around your garage. This is the small trench that's formed in the soil and turf where the rain drips down each time it rains. Soil erosion from runoff can cause two problems: damage to the turf and foundation issues. Turf damage can be a nuisance, but foundation concerns can become a costly problem.
The simplest fix is to install a gutter system that routes the water away from your foundation. You can set up a down spout to empty into a nearby garden bed, or choose a buried spout that allows the water to soak in below ground or routes it away via a French drain system.
#3: Entry Drips
It's no fun getting a large, cold drop of water down your back when walking through the garage access door after rain or heavy dew. If the access door is on the downward slope side of the roof, adding gutters is your best option.
If the drips are coming from edge of the roof where guttering isn't necessary, a small awning with a short length of guttering right above the door can fix the problem.
#4: Rotting Siding
Maybe you don't have roof drainage problems. Your garage doesn't flood, the drips don't bother you, and you have a French drain system installed around the garage to route water away. Have you taken a look at your siding? If your garage roof doesn't extend out sufficiently, water can drain off the roof and down the siding. This can destroy the paint and cause rot on wood siding, or lead to ugly algae stains on metal and vinyl. Gutters can save you an expensive siding replacement or cleaning later on.
Whether it's an annoying wet floor or a more substantial problem, the sooner you get it fixed, the better. Often, the simplest solution when it comes to roof drainage is to route the water away from the problem area with gutters. Talk to resources like Custom Exteriors for more information.