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All posts in Shingle Roof Repair

Sumner Roofing repairs shingle roofs.


Slipping: Delaminating / Sliding

Shingles may delaminate and slide. This is caused by improper fastening. Shingles are designed to be nailed in a specific area, increasing wind resistance and ensuring that both parts of the shingle are attached to the roof. Today’s shingles are constructed in two parts. The “base” and the “dragon tooth” overlay. When fasteners do not penetrate both parts of the shingle the base can come apart, especially on high pitch roofs.

Torn/Cracked/Broken Surface

Often in high wind events we see the corners of shingles tear. This is common on contractor grade shingles. Sometimes a tree branch or flying debris may impact a shingle causing damage. 3rd party damage is another issue. As people walk across the roof they can cause damage. Damaged shingle leave the underlayment showing, accelerating roof wear.

Roof Recovered

Often used as a way to escape the costs associated with replacing flashings, installing new underlayments and saving labor for tear-off shingle recovers offer an option. We have found shingle recovers cause rapid wear of the primary roof system as they trap moisture and “bake” the original roof. Without replacing flashings, there is no way to ensure a watertight installation. We do not recommend shingle recover applications.

Offset Not Correct

Shingles are not a waterproofing material. When installed correctly, they do “shed” water. However, if installed on a flat roof, they would allow massive seepage. The way shingles work is by their overlapping design. As the previous layer is covered by the next it creates a stair step water shed design, disallowing seepage. This stair step design also has a vertical component to it. If each row is not offset correctly, water may enter the system.

Improper Number of Fasteners

Shingles are designed to be installed using special wide head roofing nails. Each shingle has a designated “nail line”. If shingles are fastened outside the nail line the manufacturer’s warranty is voided and the roof assembly is out of code. This also leaves the roof susceptible to roof blow-off in the event of strong winds. In 1994, when the new code system was introduced, the requirement was 6 nails per shingle. It has since been reduced to 4 nails per shingles. However, most of the good roofing contractors still install 6 and in order to achieve the enhanced wind warranty, 6 nails per shingle must be installed.

Improper Roofing Fastener Installation

It is important that all fasteners are installed perpendicular to the roof’s surface and driven in at a perfect 90 degree angle. Shown are areas where the roofing fasteners were not driven straight in and the fastener heads are lifted slightly. Over time this can and will damage the roof system and allow seepage.

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. The photos show incompatible fastener types were used and electrolysis is occurring.

Fasteners Uplifting

During roof 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 asphalt shingle seals to itself a tight bond is formed. “High nails” begin to protrude through the top surface of shingles. Rusting and seepage can occur. It is also possible for the roof’s underlayment fasteners to uplift.

Blown Off Cap

The most susceptible area on a roof to wind damage is the cap. Cap shingles are used to cover the hip and ridge areas of two adjoining decks. Most installers simply use a 20-years 3-tab shingle, cut into pieces and placed in this area to act as cap and save money. Each manufacturer makes specially formulated cap shingles with aggressive adhesive to prevent blow-off. When it is time to replace the roof ask your contractor to use special Hip & Ridge Cap shingles made to withstand high winds, keep the shingle system guarantee and match the field shingles.

No Starter Strip

Starter strip shingles are used to seal the first row of perimeter shingles and prevent wind uplift. When starter strip shingles are omitted or not installed correctly strong winds have an opportunity to lift the first row of shingles and cause the “domino effect”. This has led to entire roofs being blown of during hurricanes. The photos show where starter strip shingles were not installed correctly on this Nashville roof. Proper sealant was not installed. As a temporary measure the first row can be lifted and sealed. When it comes time to replace your roof make sure your contractor uses specially designed starter-strip shingles to keep your roof’s guarantee and prevent system blow-off

Flat Tie-In not Sealed Properly

The junction between your pitch roof and the flat roof is called the “tie-in”. This area is specifically important because there are two different roofing materials joining. It is also very important that the two roof systems have the correct flashing detail and extra sealant protection

Backwater Laps

When installing a shingle 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 shingle roof, if two seams are lapped in backwards a backwater lap occurs. This can “cup” water and force in under the layers, causing leaks.

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.

Flashings Inspection

Flashings are the most important part of any roof system. Specially designed for their unique applications, flashings bridge transition areas and prevent seepage.

Flashing Rusting

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. I have found rusted flashings on this Mufreesboro roof. Rust cannot be simply sealed over, as it will continue to grow. 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.

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.

Gable End Flashing Not Correct

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 Sumner Roofing & Exteriors’ #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.

Boot Lapped / Sealed Correctly

As with all roof-top 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 on this Hendersonville roof. 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.

Vent Not Lapped / Sealed Correctly

As with all roof-top 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 Westmoreland 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.

Plastic Boots 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. In this case a plastic stack flashing was used to seal the pipe. A gap between the pipe and surrounding flashing is visible and allowing seepage. The boot on this Lakewood roof should be removed and replaced with a new lead boot.

Ell Flashing Not Sealed Properly

Ell flashing bridges the transition from the roof’s surface and a wall or upright surface such as a curb. The ell flashing has not been sealed properly and the shingles are pealing back from the flashing allowing seepage. This can be correctly by removing the area and installing mastic sealant correctly. New membrane may need to be installed in this area. Also, if the ell flashing cannot be cleaned or has too many old fastener holes in it, the entire flashings detail area may need to be replaced.

No Ell Flashing Installed

Whenever a roof surface meets a vertical surface ell flashing is needed to bridge the transition and protect from seepage. On this Franklin roof we found no ell flashing was installed at this detail. Although sealant may have helped avoid leaks, over time sealant breaks down. The correct technique is to install ell flashing here.

Ell Flashing Uplifting

Ell flashing should be nailed every six inches on center. On a Pasquo roof I found the ell flashing uplifted. Not enough fasteners were used and the sealant has deteriorated. We suggest sealing the underside of the ell flashing and installing the correct number of fasteners as specified by code. Another layer of membrane or shingle should be installed to cover the ell-flashing flange and provide a more aesthetically pleasing transition area.

Ell Flashing Behind Wall Surface

Ell flashing is designed to bridge the roof to wall transition and allow for protection against water intrusion. Water which runs down the roof and wall is caught by the ell flashing and channeled to the roof’s edge. It is important that the ell flashing’s end be flared so it sticks out past the siding/stucco. On this Whites Creek roof the installers did not flare the flange end and it terminates behind the siding/stucco. This provides a direct path for water to flow behind the wall surface and into the building. Often this type of leak takes time to show and may only be noticeable in heavy rains and the wall needs to soak enough to be evident. The only correct way to repair this issue is to add a layer of membrane over the existing flashing that directs water flow out and away from the wall. Some roofers may suggest cutting out the old flashings and installing new. We do not suggest this, as it is impossible to replace the wall surfacing material and regain integrity.

Fasteners In The Valley

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. A standard installation guideline on all roof systems is to never install fasteners in the valley’s center. Exposed valley fasteners disrupt the immediate flow of water. Because valleys are transition areas and absorb building movement, fasteners installed in the valley center uplift and allow water seepage. The only way to properly repair this issue is by replacing the valley flashing.

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. Ell flashing seams were separating here 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.

No Wall Cap / Coupling

Separation fire walls are designed to extend past the roof level and protect against spreading flames in the unlikely event of a fire. Many times these walls are simply stuccoed and painted. Over time the paint deteriorates, often at rates faster than walls due to the direct sunlight they receive, and allow moisture to seep into the wall’s core. Under a maintenance program these wall caps can be coated using an elastomeric paint sealant. Other times it is best to use some type of wall cap to permately protect the wall enclose area. When moisture enters the wall it causes moisture bleed out and swelling. The additional moisture content is trapped and cannot evaporate causing further damages to fasteners, flashings and framing. The swelling can rust out concrete rebar and steel straps, both structural components of the wall. The correct way to fix this is to treat the wall top as a roof and install a roof system on it. This can be achieved by installing a metal coupling or a flat roof membrane with flashing on all four sides of the wall’s top. The flat roof membrane is a better detail as it provides one continuous piece and protection without added maintenance.

Off Ridge Vents Not Angled

Vents are installed on the roof to allow for attic airflow. These vents should not be longer than four feet in length and should be installed at an angle. As water flows down the roof it often is blocked behind the vent creating a small area of water ponding. Ponding water is water sitting on any asphalt roofing material longer than 48 hours without run-off or evaporation. As the water sits it magnifies the sun’s rays and works on breaking down the sealant and underlayment used to seal the vent to the roof. The correct way to fix this issue is to install a new vent. These vents were not installed with the correct angle and water is ponding behind them.

Pitch Transition Not Flashed

Whenever two different roof pitches transition a specially designed flashing is needed to bridge the slope change. This Nashville 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.

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 Walton Oaks 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.

Fair/Unfair Metals Touching

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. Electrolysis is occurring on this roof.

Pan Roof Tie-In Not Correct

Aluminum structures are inexpensive and easy to install. They often add value to a building by providing additional usable space. The roofing system is typically a pan or super-pan type made of aluminum and coated white. Insulation is sometimes used to help insulate and dampen rain patter. Pan roofs are large and lightweight. They are often fastened directly to the fascia board of a germinate structure and sealed with a simple bead of silicone caulk. During even light winds the entire structure moves causing the caulk bead to break and open and area for water to penetrate causing seepage at the tie-in and along the ribs. Since the caulking will not reseal it is our suggestion that a transition membrane be used to cover the tie-in area as would be installed on a normal flat roof tie-in. This will prevent water seepage and stop the fascia board from rotting.

Drip Edge with Flat Shelf

Often associated with gutter installation and plumb fascia boards, perimeter drip edge flashings can create a shelf or ledge about three inches from the roofs edge. This shelf creates a flat roof area at the roof’s perimeter. Since this roof system is not a flat roof, the perimeter flashings are not designed to allow for sitting water. During light rains and morning dew water seeps under the roof system and deteriorates the perimeter decking sub-fascia board and fascia board. This can be resealed as a temporary fix, but should be replaced for a more germinate measure.

Granules Loss

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 occurs 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 on a Mt Juliet roof is an example of granule loss and the starting of shingle breakdown. This is a sign that roof replacement is near.

Aluminum Ridge Vent w/Nails

Aluminum ridge vents are installed across the crown of the roof to allow ventilation. Although the vent manufactures allow these vents to be installed with aluminum nails, the nails they provide are not long enough to penetrate the decking. Most roofers will simply use the same nails as they use for installing shingles. However, these nails are galvanized and the vents are aluminum, fair and unfair metals, which lead to electrolysis. We suggest these nails be sealed and screws with special EPDM gaskets at the screw’s head be installed to prevent vent blow-off, self seal the fasteners and prevent further electrolysis.

Fiberglass Intermat Showing

Shingle construction starts with a fiberglass intermat. During production the fiberglass intermat is saturated with asphalt and dried repeatedly until the desired thickness is achieved. This intermat is not a waterproofing layer but is necessary to keep the shingle from cracking and separating. Over time the shingles surface wears down. Eventually the intermat will become exposed. It is generally accepted that when this occurs it is time to replace the roof. Without the fiberglass intermat holding the shingle construction together the shingle cannot longer withstand thermal shock (expansion and contraction) and will crack, possibly allowing seepage. You may want to consider replacing the roof at this time.

Shingles Curling

Asphalt, an oil based product, is resistant to water and used in a wide range of waterproofing areas. Shingles are primarily asphalt in construction. Asphalt does dry-out over time. This process is called oil migration. As with most natural elements, when asphalt dries it shrinks. The shingle’s fiberglass intermat tries to prevent the shrinkage. This event is visible on this La Vergne roof. We typically find shingle’s corners curling. Improper ventilation accelerates the curling process. If shingle curling is occurring on your roof, roof replacement is near.

Shingle “W” Valley

There are three main ways to install a shingle valley. First is the correct way, by fully lacing the low side plane through the valley so a full shingle is in the valley protecting the flashing and then the second plane is installed and cut straight with the valley center. Second it a full lace valley where both sides are laced through the valley. This causes “bridging” or uplifting of the shingles and leads to seepage. Third, which is both least expensive and allows the most number of leaks, is by cutting the shingles before they lace through the valley by installing a “W” type valley metal. This is a major installation shortcut as it saves in both shingle and labor expense. However, the biggest issue with this type of installation is the seepage problems it causes. By cutting the shingles without lacing all the way through the only form of protection is a small bead of sealant on either side of the valley. On roof with a pitch over 5 in 12 the issue is more prevalent as the water jumps over the center valley ridge and is driven under the shingles. This Hendersonville roof has been installed with an open valley and is showing signs of sealant breakdown, which may be allowing seepage.

Turbine Vents Not Working

Turbines, or whirly birds ventilation units are found on many homes and can be the source of some roofing issues. In a high wind, driven rain situation water enters the vent through the vent’s “gills”. We have found bearings to be a normal maintenance item as they wear out and the vent ceases to work properly. We recommend replacing this type of vent.