Roof flashing provides the additional safeguard to the surfaces where water is likely to leak. They cover the edges of chimneys and skylights, under the shingles, soil stacks, vent pipes, roof valleys including the intersection of the roof deck and dormer walls.
You are aware that there are a number of different components in your roof which must work in combination with your flashing material. They are your roof sheathing, underlayment, roofing material, roof intersections, ventilation and flashing details. Each apparatus must be installed properly for the system to function well and bolster the waterproof barrier of the roof structure.
But because of expansion and contraction due to weather changes, your roofing components are susceptible to ordinary wear and tear and deterioration. With regards to roofing flashings, if they are installed the wrong way, you will notice typical defects.
For instance, if the seals that hold the roof flashing around your chimneys and vents are broken, it is a simple job of chipping them away and applying roofing cement as required. After which, have the flashing reinstalled and seal it again until it dries. When it comes to low slope roof flashing problem, some of the causes are its sealant may be cracked, the clamps are loose, incompatible materials, ineffective or missing scuppers or loosened up fasteners.
For hip and ridge flashing drip edge, the problems may be the materials are coming apart, the fasteners may not be sealed, excessive exposure, loose, misaligned or missing nails, overlaps not alternated and rust. When it comes to plumbing vent pipes/stacking flashings, you may find that they are open at the top, plenty of rust, damaged, exposed and missing fasteners, vertically misaligned, wrong material or wrong size and top of flashing exposed or bottom buried.
The common defects of chimney flashings are the pan is inappropriate or missing, its cap flashing is too short, the cricket is missing, loose or damaged, seams are open, patched, damaged or loose, the base or cap flashings are missing, the top, bottom or side flashings are missing, inadequate overlap on base or cap flashings, rust, side base flashings are quite short and the side base flashings are not properly set into the shingles.
When it comes to valley flashings, its usual problems are above eave protection, above underlayment, closed cut valleys are not trimmed 2 inches back, closed valleys with wrong material, unwidened bottom, exposed fasteners, metal pieces are too long, windows used as a skylight, uncut points, wrong application, rust or rotten materials, no upstand or edge break, shingles not sealed to metal, loose, patched, damaged, open seams, wood joints break into valley and wrong, incomplete flashings.
Now, with regards to roof joining the wall flashings, the customary situation is something is missing and not continuous. The base flashing system should prevent the water from entering the house. Counter flashing should turn the water from the wall up to the roof or base flashing. A removable counter flashing is cost effective for repair of all membraned roofing systems.
So when you need to repair or replace your roof flashing because of water sippage, make sure to contact a licensed roofing specialist who will install it the right way. Have it regularly inspected, cleaned and properly maintained!