When installing a roof system it is important to always start at the lowest point and proceed upward toward the roof?s peak. This ensures that each layer of materials overlaps the previous. Even on flat roofs, this principle is important. As water travels, on a pitch or on a flat roof, if two seams are lapped in backwards a backwater lap occurs. This can ?cup? water and force in under the layers, causing leaks.
Steel metal flashings exposed to the elements can rust over time. Today’s flashings are made of galvanized metal, a process that protects the steel core from rusting. Rust cannot be simply sealed over, as it will continue to grow as seen on this roof. The rust needs to be cut out and a new flashing installed, then sealed properly. Since the rust is open to the surface and flashings are vital to the integrity of your roof system. We suggest repairing the rusted flashing areas before seepage causes structural damage.
No Sealant at Flashings
Although flashings bridge transitions in the roof, when not sealed properly they are ineffective. Flashing is designed to turn corners and breaks in a roof, which tend to have more movement than other areas. If not sealed properly, these flashings do little to stop water from entering the roof system. This is allowing water to enter the flashing detail area. This can be repaired with minimal expense.
Incorrectly Sealed Boot Flange
As with all rooftop objects it is important that proper water flow and installation are considered. Flashing that is not layered correctly and sealant applied in the right junction areas allow water seepage. The boot flange was not installed correctly with the proper overlap procedure. Sealant has done a good job covering up the installation error, but is now showing signs of deterioration. Adding sealant may prevent seepage temporarily but is not a roof cycle solution. The boot should be replaced and installed correctly.
Flashing Seams Separating
Flashing seams must be overlapped correctly and an adequate amount of sealant placed in between the overlap area to ensure proper waterproofing at the ell flashing transition area. Here we found ell flashing seams were separating and in need of additional sealant. The correct way to repair this area is to replace the flashing with new. That is the only way to ensure the flashing detail area will not leak.
Offset Not Correct
Sprayed Polyurethane Foam (SPF) is not a waterproofing material. When installed correctly, with a heavy waterproof coating and a slight pitch, it does “shed” water. However, SPF foam has millions of small holes called air pockets created at the time of installation. These holes give SPF its insulating properties. As the coating breaks down and allows water into the system the moisture is trapped and causes seepage. We do not suggest spending money on yearly coatings. It is advisable to save funds and replace the SPF roof with a certified roofing system.
Torn, Cracked Or Broken Surface
As a roof expands and contracts the roof system moves. This is a daily occurrence and is associated with Thermal Shock. During movement the membrane binds against each other. Sometimes a tree branch or flying debris may impact the roof causing damage. 3rd party damage is another issue. As people walk across the roof they can cause damage. The membrane on this roof has been damaged. Since this leaves the underlayment showing, it is our recommendation these areas are repaired.
A code violation and warranty exclusion on all asphalt based roof systems, ponding water is when water sits on a roof for more than 48 hours without being evaporated or running off naturally. Water ponding breaks down asphalt, which is an oil-based product. Think of potholes in the road. Or, imagine a pot of boiling water when cooking. If oil were added, it would stay on top of the water. On a roof the opposite effect happens. The oil is trapped at the bottom and due to it’s natural properties, tried to rise to the top causing oil migration. Oil migration when the oil and waterproofing properties of a roofing product are pulled out, causing the roof system to break down.
“High nails” were found on this roof. During roof underlayment installation it’s easy for installers to forget about proper pressure setting on their nail guns. In most cases too many nailers are hooked up to a low volume compressor and the air supply is not sufficient to drive each fastener fully. At time of installation only the severe “high nails” are noticeable. When the modified membrane seals to itself a tight bond is formed. “High nails” begin to protrude through the top surface of membrane causing rust and seepage.
No Starter Strip
Membrane Starter strip is a narrow strip of membrane at the perimeter designed to seal perimeter flashings and prevent wind uplift. When membrane starter strip is omitted or not installed correctly strong winds have an opportunity to lift the first row of membrane and cause the “domino effect”. This has led to entire roofs being blown of during strong wind events. The starter strip on this roof was not installed correctly. Proper sealant was not installed. As a temporary measure the first row can be lifted and sealed. When it comes time to replace the roof make sure your contractor uses specially designed starter-strip membrane to keep your roof’s guarantee and prevent system blow-off.
Improper Fastener Type
When two different types of metals come in contact a chemical reaction occurs: Electrolysis uses moisture as catalysis at a molecular level to pass ions from one metal to the other. The process causes a deterioration of both metals similar to the effects of rust. Using the wrong type of fasteners causes a real concern due to the importance of the fastener itself. Electrolysis causes the fastener puncture to deteriorate and widen, allowing a water path and seepage. Incompatible fastener types were used and electrolysis is occurring.
Vent Not Correctly Sealed
As with all rooftop objects it is important that proper water flow and installation are considered. Flashing that is not layered correctly and sealant applied in the right junction areas allow water seepage. The vent flange on this roof was not installed correctly with the proper overlap procedure. Sealant has done a good job covering up the installation error, but is now showing signs of deterioration. Adding sealant may prevent seepage temporarily but is not a roof cycle solution. The vent should be replaced and installed correctly.
When two different types of metals, fair and unfair as they are called, come in contact a chemical reaction occurs. Electrolysis uses moisture as catalysis at a molecular level to pass ions from one metal to the other. The process causes a deterioration of both metals similar to the effects of rust. Using two different types of metal causes electrolysis and the rapid breakdown of metal.
Plastic Boot Used
As you know, plastic typically dries out rather quickly in our environment. The sun’s UV rays cause oil migration much the same as it does to exposed asphalt. On this roof a plastic stack flashing was used to seal the pipe. A gap between the pipe and surrounding flashing is visible and allowing seepage. This boot should be removed and replaced with a new lead boot.
Valley Metal Buckling
Valley metal is installed by crimping the valley center, fastening the entire length of both edges and then applying mastic to cover the valley metal edge and fasteners. When valley metal is not properly pressed, fastened and/or sealed it causes buckling and waving. Since a valley is designed to channel water between two pitch areas a valley receives more water flow than any other part of the roof. Valley metal buckling disrupts the immediate flow of water and creates water vortices, a circular flow of water that leads to roof seepage.
Incorrect Gable End Flashing
Gable ends are where a valley terminates into a roof’s surface, rather than running the entire length to the roof’s edge. They are quite common and add to the roof’s design. However, if not correctly detailed with flashings and sealants, the gable end is an area of concern. With the valley channeling large amounts of water to the gable end area there is an increased chance of seepage. In fact, it is roofing’s #1 repair area on all roof systems. Adding more sealant may stop the seepage for a year or so, but the only correct way to fix this area is by removing the flashings and installing them correctly. This will minimize the dependence on sealants, which will deteriorate over time.
Counter Flashing Loose
Counter flashing is metal flashing installed into the wall to protect the roof membrane from coming loose from the wall as it transitions from the roof area. Counter flashing can also be used in conjunction with ell flashing at the same detail area. On this roof the counter flashing, which has a concealed return flashing cut and installed into the wall, has come loose from the wall and is allowing water to enter. Counter flashing is an older flashing technique and requires constant maintenance by re-fastening and re-sealing the top wall cut to disallow seepage. This area should be repaired before interior damage occurs.
Pitch Transition Not Flashed
Whenever two different roof pitches transition a specially designed flashing is needed to bridge the slope change. This roof does not have the correct flashing and is relying on sealant to disallow seepage. Over time the sealant will deteriorate and allow leaks. The pitch transition on your roof does not have any flashing in it. Eventually the roofing materials and mastic used to seal this area will cause interior damages.
Asphalt does not hold up to direct UV exposure. Shingles use small colored stone chips called granules to protect the asphalt from environmental elements and to provide an esthetically pleasing look. Over time these granules wear off. When this happens the asphalt surfacing starts to break down causing a downward turn in the shingle’s life. This is the reason why it is not recommended to pressure clean a shingle roof. Pressure dislodges the granules from their asphalt embedment. We have found improper ventilation to be a major cause of premature granule loss. It is also important to keep overhanging trees trimmed so they don’t brush off granules. Here is an example of granule loss and the starting of shingle breakdown. This is a sign that roof replacement is near.
Punctures in Roof
Flying debris, animals and old rooftop items can all cause holes in the roof. Punctures are major concern because there are no roofing materials protecting the building from water intrusion.