The following information describes some of the common area where leaks occur.
Missing or Damaged Shingles
This is a fairly common problem that may or may not cause a leak. Either way the problem needs to be fixed. Shingle roof systems create a water barrier that consists of multiple layers. A missing or damaged shingle removes one of these layers and greatly increases the risk for a leak.
This problem will eventually happen to all shingle roofing systems. As the shingle ages the oils in the asphalt dry out and the shingle shrinks. The rate of shrinkage is greater on the surface of the shingle than in the middle and this is what causes them to curl. The shingles also become brittle as they dry out making them very susceptible to damage. When shingles reach this condition simply walking on the roof can cause damage. Repairing a leak on a roofing system that is in this condition is very difficult if not impossible. Good attic ventilation will slow this process down and add longer life to the roofing system.
Plumbing vents, stove vents, bathroom vents, anything that penetrates the roof covering system is a potential area for a leak to occur. Plumbing vent seals, in this area, are typically a lead covering that extends from under the roofing system, up the pipe and is then folded inside the vent pipe. The area where the lead meets the roof covering is a common place for leaks to occur. Often times we see the top of the lead covering has been eaten away by squirrels allowing water to penetrate. A less common type of vent seal we see in this area is a plastic and rubber device that slips over the pipe and under the roof covering. This device is less expensive than the lead covering but have a much higher failure rate.
Leaks around vents typically can be easily fixed as long as the decking under the roof covering has not deteriorated. Fixing a leak as soon as possible can save lots on money.
Chimneys can be challenging areas to install roofing materials around and create a waterproof seal that will last for many years. Flashing is used to seal between the roofing material and the vertical sides of the chimney. Failures of the flashing system or any mistakes made with the installation of the flashing will result in leaks. Leaks around chimneys need to be addressed by an experienced, professional roofing expert.
Nails backing out. This is without a doubt the most common problem that is seen with shingle roofs. On almost every shingle roof that is more than 5 or 6 years old you can find at least a couple of nails sticking up. The theory is heating and cooling of the roof causes a very small amount of expansion and contraction. This small amount of movement is thought to be what causes the nails to back out. The good news is this problem is easily fixed.
High winds from hurricanes, tropical storms, and strong afternoon thunder storms can damage shingles, vents, and various other elements of the roofing system. Any part of the roofing system that has been damaged has the potential to leak and should be fixed as soon as possible. Rain that is being driven by high winds can be forced under loose shingles. This may result in leaks that would not occur during normal rain events. To prevent this problem any loose shingles must be secured.
The roof is not just shingles nailed to some plywood, it is a system consisting of many elements providing multiple layers of protection from the elements. A mistake in the installation of any one of these elements is a potential leak. The roof system should be installed by experienced professionals. If the installation is not done correctly it will result in leaks in the future and potential structural damage if not fix in a timely manner. If you find yourself in a situation where an installation mistake has caused a leak, you need to hire an experienced professional to do the repair. Our professionals will know what the problem is and how to correctly fix it.
Flat and Low Slope Roofing
This type roofing is susceptible to most of the same issues as any other type system. When a leak does occur in a flat deck or low slope roof it can create a major problem because the water is staying on the roof longer than it does on a high slope roofing system.
Flat or low slope roofs are commonly used on porches and room additions to structures with a high slope roof covered with shingles. The area where the roof transitions from shingles to flat deck is a common area to find leaks. Typically the leaks are caused by improper installation of the materials needed to make the transition from shingles to flat deck. Flat deck and low slope roofing materials do not last as long as shingles so chances are that you will need to replace the flat deck roof before the shingle roof. This work needs to be done by a roofing professional because of the skill level required to properly rework the transition area.
This information also applies to aluminum porches. The transition from a shingle roof to an aluminum roof is also a common area for leaks. If this transition is not done correctly water can get under the shingles and onto the plywood decking. The leak will be above the eve and may not be noticed right away. This prolonged exposure to water will cause the plywood deck to rot. This will result in a costly repair that can be avoided by doing the job correctly.
This is an area where we occasionally see leaks. A galvanized sheet metal strip is placed along the entire length of the valley under the shingles. If the is damaged during installation or not completely covered by the shingles problems can develop. Prolonged exposure to the elements can cause the galvanize coating to deteriorate and the metal to rust.
As you can see from reading through this information a lot of the problems are caused by human error and poor workmanship. Often times that good deal you are getting on your roofing work may not be such a good deal in the long run. Hiring a licensed professional with the knowledge and experience to do the correctly can give you years of trouble free service.