Be very careful before climbing on the roof for DIY repair or maintenance; you can easily cause your roof to leak if you aren't careful. Here are some of the reasons some DIY roofing projects end in roof leaks:
Walking On the Roof
Roofs are more delicate than most people think. This is why you are advised to call a roofing contractor anytime you have a roofing job that involves climbing and walking on the roof. For example, the friction between your shoes and the shingles can dislodge the protective granules off the shingles, exposing them to damage from different weather elements. You may also accidentally drop tools on the roof, causing damage that may let water leak into the roof.
Cleaning the Roof Using the Wrong Techniques
Cleaning the roof is a necessary regular maintenance practice, but it will only help you if you do it right. Using the wrong washing materials or techniques can actually cause damage to the roof. For example, raking snow off the roof can damage the shingles and cause leakage. Using a power washer on asphalt shingles may also strip the protective granules off them leading to damage and leakage.
Improperly Installing Flashing or Failing to Install Flashing
Flashing (typically metal) is installed in roof corners and joints to reduce the risk of leakage. This means the roof can easily leak if the flashing is not installed or if it is installed in the wrong way. A common DIY mistake is to cut the flashing material too small leaving a section fo the joint or corner exposed.
Nailing Shingles Improperly
If you are replacing damaged or missing shingles, you need to master your nailing technique. Otherwise, the shingles will not stay on the roof and leakage may follow. For example, if you don't nail the shingles tightly enough, they can easily be blown away by strong winds. At the same time, overdriving nails into a shingle also puts too much pressure on the shingle, increasing the risk of cracking.
Installing Gutters with the Wrong Slope
The gutters also play a role in preventing your roof from leaking because they collect and channel water away from the roof. This can only happen if the gutters are installed with the right slope that allows water to drain into the downspouts. Without a proper slope, water can stagnate within the gutters and even flow back under the roof, causing damage.
As you can see, the danger of damaging the roof in the course f a DIY repair is real. Ideally, any repair that involves climbing on the roof should be handled by a residential roofing company.