1. Poor Roof Construction -- This has become a serious problem in the past 15 years or so. Due to constant changes in the economy, the bidding on new structures (which includes virtually every kind of building including schools, hospitals, apartment buildings, shopping malls, and industrial buildings) has become so fierce that to get the job the roofing contractors must cut corners.
The roofing contractors must fight the weather to meet completion deadlines. Oftentimes installation continues during unfavorable weather conditions. Sometimes moisture is trapped in the roofing system and can contribute to early failure of the roof.
The results of corner cutting are cropping up, all across the country, in the form of inadequate roof insulation, poor roof decks, and the use of 2-ply instead of 3-ply and 4-ply paper in building the new roof. It is now not uncommon for a new roof to leak not long after it has been laid down.
2. Normal Aging and Weathering - A roof begins to deteriorate the day it is constructed. Its main enemy is the weather. It takes a pounding from the sun, rain, snow and sleet; it is scorched by intense summer heat and buffeted by high winds from storms. The sun dries out the roofing paper; causes the tar to run and sag, weakening the roof mat. As this oxidation soaks the oils out of the paper, it becomes brittle and subject to cracking and splitting; and when the weather suddenly changes, the extreme expansion and contraction brings the ultimate disaster - A roof leak!
3. Settling of the Building - All buildings settle; It is their nature, but some settle much more than others. When a building settles at an abnormal rate, this puts great stress on the roof. This unusual movement can, and will, create enough strain to cause a roof leak, which if left ignored will result in a general roof breakdown.
4. Vibrations - Some of these result from natural phenomena such as earth tremors, severe storms such as tornadoes and hurricanes. Even buildings located many miles from such an act of nature can get enough impact to put a strain on the building, which in turn carried to the roof can contribute to a roof leak. Other vibrations from machines, equipment, air conditioners, railroads and truck traffic cause early failure.
5. Mechanical Damage - Much more prevalent than you might think. In today's technology, it has become standard to put many pieces of equipment on the roofs; air conditioning units, phone and TV antennas, sign supports, elevator housings etc., which presents a serious problem for two reasons.
A. They put extra weight on the roof.
B. They require servicing, and every time a serviceman goes on a roof there is some danger of damage being done. Even harmlessly using a small ladder on a roof can make a small break in a flashing, which unknown to the building owner can result in leakage and damage.
